MEDICINA 2024 · Preguntas 1-50

#1 🖼️ requiere imagen 1

Mujer de 42 años que acude a la consulta de genética por un diagnóstico reciente de cáncer de endometrio. En base a los antecedentes familiares que constan en la imagen, ¿cuál de los siguientes síndromes es más probable que presente?

1 Poliposis adenomatosa familiar.

FAP (APC gene) causes hundreds-thousands of colonic polyps and colorectal cancer; endometrial cancer is not its defining feature, so this pedigree doesn't fit best here.

2 Síndrome de Lynch.

Correct. Lynch syndrome (mismatch-repair gene mutations — MLH1, MSH2, MSH6, PMS2) is the classic cause of a family pattern combining endometrial and colorectal cancer, often at young ages and across generations.

3 Síndrome de cáncer de mama y ovario hereditario.

Hereditary breast/ovarian cancer syndrome (BRCA1/2) predisposes to breast and ovarian cancer, not endometrial cancer as the leading tumor.

4 Síndrome de Cowden.

Cowden syndrome (PTEN) causes macrocephaly, mucocutaneous hamartomas, and increased breast/thyroid/endometrial cancer risk, but is far rarer and doesn't match a classic Lynch-type pedigree.

⭐ High-yield pearl

Endometrial + colorectal cancer clustering in a family = think Lynch syndrome first. Lynch syndrome is caused by germline mutations in DNA mismatch repair (MMR) genes, leading to microsatellite instability (MSI-H) and a markedly increased lifetime risk of colorectal AND endometrial cancer, plus ovarian, gastric, and urothelial tumors.

Syndrome	Gene(s)	Signature cancers
Lynch	MLH1/MSH2/MSH6/PMS2	Colorectal + endometrial
FAP	APC	Colorectal (with polyposis)
HBOC	BRCA1/2	Breast + ovarian
Cowden	PTEN	Breast + thyroid + endometrial (rare)

Any woman with endometrial cancer and a family history suggestive of colorectal cancer should be referred for Lynch syndrome (MMR/MSI) testing.

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Paciente de 65 años que acude a urgencias por disminución brusca de agudeza visual en ojo derecho. La retinografía de dicho ojo se muestra en la imagen. Uno de los siguientes tratamientos está indicado para una enfermedad que es un factor de riesgo para esta situación. Indique cuál.

1 Latanoprost y timolol.

Correct. Latanoprost and timolol are IOP-lowering drugs used to treat glaucoma, and elevated intraocular pressure/glaucoma is a recognized risk factor for retinal vascular occlusion (the sudden painless vision loss described here).

2 Flecainida.

Flecainide is an antiarrhythmic drug with no relevant link to retinal vascular occlusion risk.

3 Hidroxicloroquina.

Hydroxychloroquine itself causes a toxic retinopathy (bull's-eye maculopathy) rather than treating a risk factor for vascular occlusion — it would be the wrong direction of reasoning.

4 Complejos vitamínicos y antioxidantes.

Vitamin/antioxidant complexes (e.g., AREDS formulas) are used to slow progression of dry age-related macular degeneration, a different disease with a different presentation (gradual central vision loss, not sudden).

⭐ High-yield pearl

Sudden painless monocular vision loss → think retinal artery occlusion. Central/branch retinal artery occlusion presents as sudden, painless, unilateral vision loss. Elevated intraocular pressure from glaucoma is a modifiable risk factor, which is why glaucoma treatment (like latanoprost/timolol) is relevant here. Always screen sudden monocular vision loss patients for vascular risk factors (HTN, atherosclerosis, glaucoma, giant cell arteritis in older patients).

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Hombre de 70 años exfumador de un paquete al día y bebedor de 2 copas de vino al día consulta por una molestia faríngea de 1 mes de evolución. Se observa exudado amigdalar por lo que se inicia tratamiento antibiótico. El resultado del test de estreptococo es negativo. La clínica persiste y se añade odinofagia con otalgia refleja y leve cambio en el timbre de la voz. Nota un bulto duro de unos 2 cm a nivel II cervical ipsilateral no doloroso. La orofaringoscopia se refleja en la imagen asociada. ¿Cuál es la sospecha diagnóstica y su manejo?

1 Resistencia bacteriana a antibioterapia recibida, precisa cultivo de exudado faríngeo con antibiograma para indicación adecuada.

A month of symptoms unresponsive to antibiotics with a hard, painless, fixed neck node is not typical bacterial resistance — repeating cultures would delay the real diagnosis.

2 Sospecha de absceso periamigdalino izquierdo, será remitido a urgencias de Otorrinolaringología para drenaje quirúrgico.

Peritonsillar abscess is acute (days, not a month), very painful, and usually causes trismus and a bulging soft palate — this chronic, painless node picture doesn't fit.

3 Sospecha de neoplasia maligna de amígdala palatina, será remitido preferente-urgente a Otorrinolaringología.

Correct. Heavy tobacco/alcohol use + >3 weeks of unilateral throat symptoms + referred otalgia + voice change + a hard, painless, fixed cervical node is the classic red-flag combination for tonsillar (oropharyngeal) malignancy, warranting urgent ENT referral for biopsy.

4 Sospecha de angina de Plaut-Vincent, remitido a Otorrinolaringología para realización de biopsia de ganglio para estudio de linfoma.

Plaut-Vincent angina (a necrotizing gingivostomatitis/tonsillitis) is an acute infectious process, not associated with a chronic hard neck mass — a lymphoma work-up isn't the leading concern here.

⭐ High-yield pearl

Unilateral sore throat + referred otalgia + hard painless neck node in a smoker = tonsillar cancer until proven otherwise. Persistent unilateral pharyngeal symptoms that fail antibiotics, especially with red flags (referred otalgia, voice change, a firm non-tender lymph node) in a patient with tobacco/alcohol exposure, should trigger urgent ENT referral for direct visualization and biopsy rather than further antibiotic trials. A hard, painless, enlarging neck node in an older smoker is a head & neck cancer red flag, not a reassuring reactive node.

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Niña de 7 años que acude por otalgia y otorrea purulenta derecha desde hace 3 semanas, tratada con antibióticos y antinflamatorios. Tras la resolución de las manifestaciones clínicas, vuelve a aparecer la otorrea por lo que se pauta de nuevo tratamiento antibiótico. A los 5 días se objetiva una tumefacción retroauricular. En la otoscopia se pone de manifiesto una leve retracción de la membrana timpánica, escasa secreción blanquecina en el conducto auditivo externo y una tumefacción retroauricular blanda que ocasiona un mínimo desplazamiento anterior del pabellón auricular. Indique el diagnóstico que sugiere la imagen de resonancia magnética mostrada.

1 Absceso subperióstico extracraneal.

Correct. Recurrent otitis media followed by retroauricular swelling with anterior/inferior displacement of the pinna is the classic evolution to mastoiditis with a subperiosteal (extracranial) abscess overlying the mastoid bone.

2 Trombosis venosa cerebral.

Cerebral venous thrombosis is an intracranial complication that would typically present with more severe neurologic signs (seizures, raised ICP, focal deficits), not isolated retroauricular swelling.

3 Absceso cerebral retromastoideo.

A retromastoid cerebral (intracranial) abscess is a more severe, deeper complication than what this exam picture (soft retroauricular swelling only) suggests.

4 Área de cerebritis retromastoidea.

Cerebritis is an early, non-encapsulated intracranial infection stage — again a more severe intracranial complication than the extracranial swelling described.

⭐ High-yield pearl

Anterior/downward displacement of the ear after otitis media = mastoiditis with subperiosteal abscess. Acute mastoiditis is a complication of otitis media in which infection spreads to the mastoid air cells; a subperiosteal abscess forms when pus breaks through the mastoid cortex, pushing the auricle forward and inferiorly — a clinical sign you should recognize on sight. MRI/CT in suspected mastoiditis is used to distinguish extracranial (subperiosteal) from intracranial complications (sinus thrombosis, epidural/brain abscess, cerebritis), which changes management urgency.

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Una mujer de 18 años acude a urgencias por dolor abdominal intenso, febrícula, test de embarazo positivo y manchado vaginal de 3 días de evolución junto con líquido libre intraabdominal en la ecografía. Se realiza una laparoscopia en la que se encuentra el siguiente hallazgo tras aspirar sangre de la cavidad abdominal. ¿Cuál es el diagnóstico más probable de los siguientes?

1 Gestación ectópica.

Correct. A positive pregnancy test plus abdominal pain, vaginal spotting, and hemoperitoneum found at laparoscopy is the classic presentation of a ruptured ectopic pregnancy — the leading cause of hemoperitoneum in a pregnant patient.

2 Quiste de ovario complicado.

A complicated ovarian cyst can cause acute pain and some free fluid, but wouldn't explain the positive pregnancy test, which is the key driving finding here.

3 Apendicitis aguda.

Acute appendicitis doesn't explain a positive pregnancy test or vaginal spotting, and doesn't typically produce hemoperitoneum.

4 Enfermedad inflamatoria pélvica.

PID causes pelvic pain and fever but is not associated with a positive pregnancy test or hemoperitoneum as the primary finding.

⭐ High-yield pearl

Positive pregnancy test + hemoperitoneum = ruptured ectopic pregnancy until proven otherwise. Any reproductive-age woman with a positive pregnancy test and acute abdominal pain needs an ectopic pregnancy ruled out first — it's a life-threatening surgical emergency when ruptured, presenting with hemoperitoneum, hypotension, and shock in severe cases. Bedside pregnancy test should be part of the initial work-up in any woman of reproductive age with acute abdominal pain.

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Hombre de 40 años que presenta cefalea brusca con exploración neurológica normal. Se realiza TC craneal que se muestra en la imagen y una angiografía cerebral en la que no se encuentra patología subyacente. El cuadro clínico más probable es:

1 Hemorragia subaracnoidea traumática occipital.

There's no mention of trauma in this vignette, and a traumatic bleed wouldn't typically show a completely normal angiogram with this distribution.

2 Hemorragia causada por una malformación arteriovenosa angiográficamente oculta.

An 'angiographically occult' AVM is a diagnosis of exclusion and much rarer than the entity below — it doesn't fit as well with a benign course and normal exam.

3 Hemorragia subraracnoidea perimesencefálica con un probable origen venoso o capilar.

Correct. Thunderclap headache with a normal exam and a negative angiogram (blood confined around the midbrain) is the classic description of benign perimesencephalic subarachnoid hemorrhage, thought to arise from a venous or capillary source, with an excellent prognosis.

4 Hemorragia causada por una discrasia sanguínea.

A bleeding diathesis would usually cause bleeding in other sites too and wouldn't specifically produce this perimesencephalic pattern.

⭐ High-yield pearl

Thunderclap headache + blood only around the midbrain + negative angiogram = benign perimesencephalic SAH. Perimesencephalic (non-aneurysmal) SAH is a distinct, benign subtype of SAH. Unlike aneurysmal SAH, it has a low rebleeding risk and excellent long-term outcome, and does not require the aggressive vascular work-up/intervention of aneurysmal SAH once an initial angiogram is negative. Don't confuse this benign entity with aneurysmal SAH — the location of blood (perimesencephalic vs. diffuse/sylvian) and a normal angiogram are the distinguishing clues.

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Hombre de 75 años consulta por un cuadro de dificultad para la marcha de 2 años de evolución de forma progresiva. Presenta reflejos vivos en las cuatro extremidades. Se muestra la RM cervical realizada. Con respecto al cuadro clínico del paciente señale la respuesta INCORRECTA.

1 El cuadro de paraparesia puede ser asimétrico.

This is a true and recognized feature of cervical spondylotic myelopathy (CSM) — the gait disturbance and weakness can be asymmetric between sides.

2 La progresión de la enfermedad es lenta pero puede acelerarse por movimientos de flexión o extensión cervical forzados.

Also true — forced cervical flexion/extension can worsen cord compression and accelerate symptom progression in CSM.

3 Se trata de una enfermedad primaria de motoneurona.

Incorrect statement (so this is the answer). CSM is a compressive myelopathy from degenerative spine disease, not a primary motor neuron disease like ALS — this is the false statement being tested.

4 La incontinencia urinaria aparece con la progresión de la enfermedad.

Also a true, recognized feature — urinary incontinence is a late finding as CSM progresses.

⭐ High-yield pearl

Cervical spondylotic myelopathy is compressive, not a primary motor neuron disease — a classic exam trap. CSM results from chronic spinal cord compression by degenerative changes (disc bulges, osteophytes, ligamentum flavum hypertrophy) in the cervical spine, presenting with slowly progressive gait disturbance, hyperreflexia, and eventually sphincter dysfunction — it is mechanical/compressive, not a primary neurodegenerative motor neuron disease.

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Mujer de 14 años derivada a Rehabilitación para el manejo de una deformidad de la columna vertebral. Tuvo la menarquia a los 10 años. En la exploración física se aprecia mínima asimetría de escápulas, el eje occipito-sacro está centrado y en el test de Adams se observa una gibosidad torácica derecha de 10 mm. Se aporta telerradiografía de columna en proyección antero-posterior. ¿Cuál de los siguientes considera el manejo más adecuado a seguir?

1 Observación, con recomendación específica de ejercicios y revisión posterior.

Correct. A small gibbosity (10 mm), minimal clinical asymmetry, a centered trunk, and a patient already 4 years past menarche (limited remaining growth) all point to a mild curve — observation with exercise and periodic follow-up is appropriate.

2 Corsé de Milwaukee a tiempo completo.

Full-time bracing (Milwaukee-type) is reserved for larger, progressive curves in a patient with significant remaining growth potential — overkill for this presentation.

3 Corsé de Boston a tiempo parcial.

Part-time bracing (Boston-type) is used for moderate curves (roughly 25-40°) — this patient's findings suggest a milder curve not yet requiring bracing.

4 Derivación a cirugía para tratamiento quirúrgico.

Surgery is reserved for severe (>45-50°) or progressive curves failing conservative management — far beyond what's described here.

⭐ High-yield pearl

Mild scoliosis near skeletal maturity → observe and re-check; bracing/surgery are reserved for larger or progressive curves. Scoliosis management hinges on curve magnitude (Cobb angle) and remaining growth potential (assessed via bone age, Risser sign, and time since menarche). A small gibbosity late in growth favors observation; larger curves or more growth remaining favor bracing; severe/progressive curves need surgery.

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Hombre de 60 años de edad que tras dolor brusco y chasquido en hombro presenta la siguiente deformidad en el brazo. ¿Cuál es el diagnóstico más probable?

1 Rotura de la porción larga del bíceps braquial.

Correct. Sudden pain/pop in the shoulder followed by a ball-like bulge in the anterior arm (the 'Popeye sign') is the classic presentation of long head of biceps tendon rupture, common in older patients with underlying tendon degeneration.

2 Rotura de la porción corta del bíceps braquial.

Short head ruptures are far less common and don't produce this classic distal bulge/Popeye deformity pattern.

3 Rotura del tendón distal del bíceps braquial.

Distal biceps tendon rupture causes a bulge more proximally (reverse Popeye) near the elbow, with weakness in supination — a different clinical picture than described.

4 Rotura del tendón del pectoral mayor.

Pectoralis major rupture occurs with a chest/axillary deformity and weakness in adduction/internal rotation, typically after a specific mechanism like bench pressing, not this shoulder 'pop' with arm deformity.

⭐ High-yield pearl

'Popeye deformity' of the arm = long head of biceps tendon rupture. The long head of biceps tendon runs through the bicipital groove and is prone to rupture with age-related degeneration; when it ruptures, the unopposed muscle belly retracts distally, creating the characteristic 'Popeye' bulge in the mid-arm.

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Paciente de 41 años, de talla baja, consulta por dolor en ambas caderas, más intenso en la izquierda. Refiere haber tenido dolor en caderas a edades tempranas aunque nunca consultaron por este motivo. Tras estudio radiográfico de caderas, se decide prótesis total de cadera izquierda, siguiendo buena evolución. Durante el postoperatorio el paciente refiere además dolor en hombros. Ante la sospecha diagnóstica se solicita una telerradiografía (ver imagen). Indique qué proceso es más probable que padezca el paciente desde su infancia.

1 Enfermedad de Perthes.

Perthes disease is a unilateral childhood hip-specific condition (avascular necrosis of the femoral head) — it wouldn't explain lifelong short stature and symmetric shoulder involvement too.

2 Osteonecrosis multifocal.

Multifocal osteonecrosis is typically an adult-onset process (steroids, alcohol, sickle cell) rather than a lifelong childhood condition causing short stature.

3 Epifisiolisis bilateral de cadera.

Bilateral slipped capital femoral epiphysis affects only the hips (usually in adolescence, often with obesity/endocrine disorders) and wouldn't explain shoulder involvement or short stature since early childhood.

4 Displasia epifisaria múltiple.

Correct. Short stature since childhood with symmetric, multi-joint (hips AND shoulders) epiphyseal disease progressing to early degenerative arthritis is characteristic of multiple epiphyseal dysplasia, a skeletal dysplasia affecting multiple epiphyses from an early age.

⭐ High-yield pearl

Short stature + symmetric multi-joint epiphyseal disease since childhood = a skeletal dysplasia, not Perthes/SCFE. Multiple epiphyseal dysplasia is a genetic skeletal dysplasia affecting epiphyseal ossification at multiple joints symmetrically, presenting with short stature and early-onset joint pain/degenerative changes in childhood, often misdiagnosed initially as bilateral Perthes disease.

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Hombre de 40 años que consulta por tumoración dolorosa en cara interna de rodilla. En el estudio radiográfico se obtiene esta imagen. ¿Cuál es el diagnóstico más probable?

1 Osteomielitis.

Osteomyelitis usually presents with systemic signs (fever, elevated inflammatory markers) and a permeative/destructive radiographic pattern, not a discrete exophytic mass.

2 Osificación heterotópica.

Heterotropic ossification typically occurs after trauma or surgery in soft tissue, not as a bony projection arising from the metaphysis of a long bone.

3 Encondroma.

Enchondroma is an intramedullary (inside the bone) cartilage lesion, usually incidental and non-painful, rather than an exophytic palpable mass.

4 Osteocondroma.

Correct. A painful mass at the medial knee with an exophytic bony lesion on X-ray is most consistent with an osteochondroma — a cartilage-capped bony projection that can become painful from overlying bursitis or soft-tissue irritation.

⭐ High-yield pearl

Painful bony bump near a joint in a young adult, radiograph shows an exophytic bone lesion → osteochondroma. Osteochondromas are the most common benign bone tumor, arising from the metaphysis as a cartilage-capped bony projection continuous with the underlying medullary cavity; pain usually comes from mechanical irritation of overlying soft tissue/bursa rather than the tumor itself.

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Hombre de 80 años, fumador. Refiere en los últimos días episodios de mareos no relacionados con el ejercicio ni el estrés, de unos 3-4 minutos de duración. Solicita atención urgente en su domicilio tras presentar un síncope, con pérdida completa de conciencia, de unos 15-20 segundos de duración. La presión arterial es 110/40 mmHg. Se obtiene el ECG de la imagen. ¿Cuál es su diagnóstico?

1 Infarto agudo de miocardio con elevación del segmento ST, anterior.

Nothing in the vignette (no chest pain description, presentation is purely syncopal/presyncopal) points specifically to an acute STEMI as the primary diagnosis here.

2 Bloqueo aurículo ventricular (AV) de primer grado.

First-degree AV block is just a prolonged PR interval and is typically asymptomatic — it doesn't cause syncope.

3 Bloqueo AV de segundo grado, tipo II.

Mobitz II can progress to complete block and cause syncope, but the vignette (recurrent presyncope culminating in true syncope with loss of consciousness) is the classically described picture of complete, not just Mobitz II, block.

4 Bloqueo AV de tercer grado.

Correct. Recurrent presyncope followed by true syncope (a Stokes-Adams attack) in an elderly patient is classic for complete (third-degree) AV block, where an unreliable ventricular escape rhythm produces intermittent pauses long enough to cause loss of consciousness.

⭐ High-yield pearl

Syncope with a wide pulse pressure in an elderly patient → think complete heart block until the ECG proves otherwise. Complete (third-degree) AV block occurs when no atrial impulses conduct to the ventricles, which then depend on an unreliable escape rhythm; transient asystolic pauses cause Stokes-Adams syncope. It requires prompt pacemaker evaluation.

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Hombre de 75 años que consulta por palpitaciones de aparición súbita hace 1 hora, sin dolor torácico ni cortejo vegetativo asociado. Tiene antecedentes de hipertensión arterial, dislipemia, hipertrofia benigna prostática y accidente isquémico transitorio hace 12 años. PA 180/109 mmHg, FC 126 lpm, Sat O2 98%. Auscultación cardíaca tonos rítmicos, sin soplos audibles. Miembros inferiores sin edemas ni signos de trombosis venosa profunda. Se realiza ECG que se muestra en la imagen. Indique, de los siguientes, el diagnóstico más probable.

1 Fibrilación auricular.

Correct. Sudden-onset palpitations in an elderly hypertensive patient with a prior TIA (a common risk factor for and complication of AF), a fast heart rate, and no chest pain fits new-onset atrial fibrillation — the most common sustained arrhythmia in this age group.

2 Flutter auricular.

Atrial flutter classically shows a more regular, 'sawtooth' ECG pattern at a fixed conduction ratio — a specific ECG pattern that would need to be confirmed, but AF is statistically far more common and fits this non-specific vignette better.

3 Infarto agudo de miocardio.

The absence of chest pain or vegetative symptoms (diaphoresis, nausea) argues against acute coronary syndrome as the primary process here.

4 Taquicardia ventricular.

Ventricular tachycardia would typically cause more hemodynamic compromise and is less common as an isolated new presentation without structural heart disease mentioned.

⭐ High-yield pearl

Elderly patient + sudden palpitations + past TIA → new-onset atrial fibrillation is the top differential. New-onset AF is common in elderly hypertensive patients and is both a cause and a consequence of thromboembolic events like TIA/stroke — anticoagulation decisions (CHA2DS2-VASc) become central to management once confirmed.

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Mujer de 69 años, obesa, con historia de apnea obstructiva del sueño, insuficiencia respiratoria hipercápnica, polimialgia reumática e hipotiroidismo de larga evolución. Acude a consulta en su centro de salud con los resultados de una tomografía computarizada (TC) solicitada por hallazgo de cardiomegalia en la Rx de tórax. Su frecuencia cardíaca es 68 lpm, y la presión arterial es 145/70 mmHg. Con inspiración profunda, sus cifras tensionales son 139/68 mmHg. Con estos datos clínicos y la imagen de la TC que se muestra, señale qué diagnóstico es más probable.

1 Neumotórax.

Nothing points to pneumothorax here — the presentation is chronic cardiomegaly, not acute respiratory distress.

2 Taponamiento cardíaco con colapso de cavidades cardíacas.

True tamponade would show hemodynamic compromise and a significant pulsus paradoxus (>10 mmHg drop with inspiration causing symptoms); this patient's minor pressure drop (145/70 → 139/68) and stable vitals argue against it.

3 Disección de aorta.

Aortic dissection presents acutely with severe pain, not as an incidental chronic cardiomegaly finding.

4 Derrame pericárdico crónico.

Correct. Long-standing hypothyroidism (a recognized cause of pericardial effusion) plus incidental cardiomegaly and a hemodynamically stable exam without true pulsus paradoxus points to a chronic, well-tolerated pericardial effusion.

⭐ High-yield pearl

Chronic hypothyroidism + incidental cardiomegaly + hemodynamically stable = chronic pericardial effusion, not tamponade. Hypothyroidism is an underrecognized cause of pericardial effusion, which can become large and chronic while remaining asymptomatic because the pericardium stretches slowly, unlike the rapid accumulation seen in tamponade.

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Paciente de 72 años con antecedentes de cardiopatía isquémica que acude a Urgencias por astenia, disnea de esfuerzo y malestar general desde hace dos semanas. En analítica se objetiva hemoglobina 7,1 g/dL, leucocitos 9.330/µL (Neutrófilos 77%), plaquetas 15.6000/µL, creatinina sérica 7,6 mg/dL (previa 1,1 mg/dL), Na+ 139 mmol/L, K+ 5,2 mmol/L. Orina: Na+ 121 mmol/L, K+ 21,3 mmol/L, cociente proteína/creatinina 3,5 g/g, eritrocitos +3, leucocitos +3. Se realiza un TC de tórax que se muestra en la imagen. Indique la actitud más correcta en relación con su diagnóstico y tratamiento inicial.

1 Neumonía atípica con fracaso renal agudo secundario a necrosis tubular aguda y el tratamiento es la administración de antibióticos de amplio espectro y hemodiálisis.

ATN wouldn't typically produce a nephritic urine sediment (heavy proteinuria, dysmorphic-type hematuria) — that pattern points to glomerular, not tubular, injury.

2 Fracaso renal agudo parenquimatoso de probable origen glomerular con hemorragia alveolar asociada y el tratamiento es inmunosupresores y plasmaféresis.

Correct. Anemia + a dramatic creatinine rise (1.1→7.6) + nephritic sediment (proteinuria, hematuria) + a lung CT abnormality is the pulmonary-renal syndrome picture — a vasculitis or anti-GBM disease causing rapidly progressive glomerulonephritis with alveolar hemorrhage, treated with immunosuppression plus plasmapheresis.

3 Síndrome urémico hemolítico atípico y hay que plantear plasmaféresis y administración de eculizumab.

Atypical HUS causes microangiopathic hemolytic anemia with schistocytes and thrombocytopenia as core features — the labs here (normal platelets, no schistocyte mention) don't support this diagnosis.

4 Fracaso renal agudo funcional secundario a insuficiencia cardíaca y hay que iniciar tratamiento con diuréticos a altas dosis y diálisis si no responde.

A purely functional (pre-renal/cardiac) cause wouldn't produce a nephritic urine sediment with heavy proteinuria — that finding indicates intrinsic glomerular disease, not a hemodynamic issue.

⭐ High-yield pearl

Anemia + rapidly rising creatinine + nephritic sediment + lung infiltrates = pulmonary-renal syndrome. Pulmonary-renal syndromes (ANCA-associated vasculitis, anti-GBM/Goodpasture) combine rapidly progressive glomerulonephritis with alveolar hemorrhage. Recognizing the combination of severe AKI with an active urine sediment plus lung findings should trigger urgent immunology work-up and early immunosuppression/plasmapheresis.

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Hombre de 68 años, exfumador desde hace 3 meses, con criterios clínicos de bronquitis crónica. Consulta por cuadro de pérdida de peso junto con astenia de un mes y medio de duración. Refiere tos seca ocasional y sensación distérmica sin fiebre termometrada. Tras realizarle la radiografía de tórax se solicita TC torácico que se muestra en la imagen. ¿Cuál de los siguientes es el diagnóstico más probable?

1 Bronquiolitis respiratoria con enfermedad pulmonar intersticial.

Respiratory bronchiolitis-ILD is a smoking-related interstitial disease, but it doesn't typically present with this degree of weight loss and constitutional symptoms concerning for malignancy.

2 Neumonía organizada criptogénica.

Cryptogenic organizing pneumonia usually presents with subacute cough/dyspnea and patchy consolidations, without the strong weight-loss/smoking-malignancy signal here.

3 Atelectasia obstructiva de lóbulos inferiores por neoplasia central.

Correct. An older heavy ex-smoker with weight loss and constitutional (B-type) symptoms should always raise concern for malignancy — obstructive atelectasis from a central endobronchial tumor is the most likely explanation given this risk profile.

4 Neumonía intersticial inespecífica.

Nonspecific interstitial pneumonia is typically associated with connective tissue disease and doesn't fit this smoking + constitutional symptom picture as well as malignancy does.

⭐ High-yield pearl

Weight loss + heavy smoking history + new chest imaging abnormality = rule out lung cancer first. In any older smoker/ex-smoker with unexplained weight loss and a new chest CT finding, lung cancer must be excluded before considering other interstitial or infectious diagnoses — the pretest probability is simply too high to ignore.

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Paciente de 63 años consulta por dolor en flanco derecho, ictericia y aumento del perímetro abdominal. Se realiza ecografía doppler y TC de hígado como se muestra en la imagen. ¿Cuál de las siguientes es la mejor opción terapéutica?

1 Colocación de una derivación intrahepática percutánea (TIPS).

Correct. Right upper quadrant pain, jaundice, and ascites with a hepatic vein/Doppler abnormality describes Budd-Chiari syndrome; TIPS is the treatment of choice for symptomatic cases not controlled by anticoagulation alone, since it decompresses the congested liver.

2 Anticoagulación oral.

Anticoagulation alone is first-line for mild/asymptomatic Budd-Chiari, but this patient already has symptomatic hepatic congestion (jaundice, ascites), which typically requires more definitive decompression like TIPS.

3 Trasplante hepático.

Liver transplant is reserved for fulminant hepatic failure or cases refractory to TIPS — it's not the first step here.

4 Angioplastia percutánea.

Percutaneous angioplasty alone (without TIPS) has a higher restenosis rate and is not the best initial option for this presentation.

⭐ High-yield pearl

Abdominal pain + jaundice + ascites + hepatic vein imaging abnormality = Budd-Chiari; TIPS is first-line invasive therapy. Budd-Chiari syndrome results from hepatic venous outflow obstruction, causing congestive hepatopathy. Management is stepwise: anticoagulation first for mild disease, then TIPS for symptomatic/refractory cases, with transplant reserved for fulminant failure.

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Mujer de 90 años que acude a urgencias por hipotensión, vómitos oscuros y dolor abdominal. Se realiza una TC abdominal que se muestra en la imagen. De las siguientes opciones, ¿cuál es la más probable?

1 Se observa gas en el sistema portal siendo indicativo de mal pronóstico.

Correct. In a critically ill, hypotensive elderly patient with dark ('coffee-ground') vomiting and abdominal pain, portal venous gas on CT is an ominous sign, typically reflecting bowel ischemia/necrosis with bacterial translocation — a recognized poor prognostic marker.

2 Se trata de una aerobilia y por tanto el diagnóstico más probable es el de colangitis.

Aerobilia pointing to cholangitis would typically come with fever and jaundice as prominent features, and doesn't match this hypotensive, GI-bleeding-type presentation as well.

3 Se observa aerobilia y pneumatosis gástrica.

The clinical severity here (hypotension, dark vomiting) fits ischemic bowel with portal venous gas rather than a more benign combination of aerobilia and gastric pneumatosis.

4 Se trata de un hallazgo no relevante en relación con una CPRE o cirugía previa.

A benign post-procedural explanation doesn't fit a patient presenting acutely unwell with hypotension and abdominal pain — this is a new, ominous finding, not an incidental one.

⭐ High-yield pearl

Portal venous gas in a sick, hypotensive patient = think bowel ischemia and a poor prognosis. Portal venous gas has very different implications depending on context: an incidental, benign finding after ERCP/biliary surgery versus an ominous sign of bowel necrosis/ischemia in an acutely unwell patient — clinical context is everything.

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Hombre de 60 años sin antecedentes de interés que acude a urgencias con un cuadro de 48 horas de fiebre de 38ºC y dolor abdominal en fosa iliaca izquierda. A la exploración abdominal destaca cierta defensa a la palpación sin peritonismo generalizado. La analítica sanguínea sólo destaca una discreta leucocitosis. La TC abdomino-pélvica se muestra en la imagen adjunta. ¿Cuál es el diagnóstico más probable?

1 Cáncer de colon izquierdo oclusivo.

Occlusive colon cancer would present with obstructive symptoms (distension, absolute constipation) rather than acute fever with localized LLQ tenderness.

2 Síndrome de Ogilvie.

Ogilvie syndrome (acute colonic pseudo-obstruction) presents with massive colonic distension without a mechanical cause, usually in hospitalized/immobile patients — not this febrile, localized-pain picture.

3 Diverticulitis aguda.

Correct. Fever + LLQ pain with localized (not generalized) tenderness and only mild leukocytosis is the classic presentation of acute (sigmoid) diverticulitis, confirmed by the CT.

4 Megacolon tóxico o infeccioso.

Toxic/infectious megacolon presents with systemic toxicity and marked colonic dilation, usually in the context of severe colitis (e.g., C. difficile, IBD) — a more severe, different picture than described.

⭐ High-yield pearl

Fever + LLQ pain + localized tenderness = acute diverticulitis, the most common LLQ abdominal emergency in adults. Acute diverticulitis is the most common cause of LLQ pain with fever in adults; CT is the diagnostic test of choice, both to confirm the diagnosis and to grade severity/detect complications (abscess, perforation, obstruction).

#20 🖼️ requiere imagen 20

Hombre de 73 años con antecedentes de hipertensión arterial y diabetes mellitus tipo 2 que acude a urgencias por presentar desde hace una semana hiperglucemia mayor de 500 mg/dL. Refiere que comenzó con dolor en vacío derecho y vómitos autolimitados. Desde entonces, disminución de la ingesta, poliuria y sensación distérmica sin fiebre termometrada. Se realiza ecografía y TC abdominopélvica sin contraste intravenoso que se muestra en la imagen. ¿Cuál de los siguientes es el diagnóstico más probable?

1 Pielonefritis enfisematosa obstructiva.

Correct. A poorly controlled diabetic (glucose >500) with flank pain and systemic toxicity should raise concern for emphysematous pyelonephritis — a severe, gas-forming renal infection seen almost exclusively in diabetics, often with underlying obstruction, requiring urgent urologic management.

2 Necrosis papilar renal.

Renal papillary necrosis typically presents with hematuria and colicky pain from sloughed papillae, rather than this systemic toxicity/gas-forming infection picture.

3 Pielonefritis xantogranulomatosa.

Xanthogranulomatous pyelonephritis is a chronic, indolent destructive kidney infection (often with an obstructing staghorn calculus), not an acute severe presentation like this.

4 Absceso retroperitoneal perirrenal por apendicitis aguda evolucionada.

A perirenal abscess from evolved appendicitis would be an unusual, roundabout explanation compared to the much more likely diabetes-related emphysematous pyelonephritis given the clinical context.

⭐ High-yield pearl

Poorly controlled diabetes + flank pain + systemic toxicity = emphysematous pyelonephritis is the feared diagnosis to exclude. Emphysematous pyelonephritis is a necrotizing, gas-forming renal infection that is a true urologic emergency, almost always occurring in patients with poorly controlled diabetes, sometimes with urinary tract obstruction — prompt imaging and urgent urology involvement are essential.

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Mujer de 57 años con enfermedad renal crónica que presenta astenia, hipotensión y cianosis en manos tras una sesión de diálisis. En la analítica se detecta anemia normocítica (Hb 7 g/dL, VCM 96 fL) con discreta reticulocitosis, leucocitos y plaquetas normales; aumento de LDH y hemoglobina libre en plasma elevada. El estudio inmunohematológico muestra un anticuerpo con especificidad anti-P. Se realiza frotis sanguíneo (ver imagen) mediante punción digital. El diagnóstico más probable es:

1 Síndrome hemofagocítico.

Hemophagocytic syndrome presents with fever, cytopenias across multiple lines, and hyperferritinemia — not this isolated cold-triggered hemolysis with an anti-P antibody.

2 Hemoglobinuria paroxística a frigore.

Correct. An anti-P (Donath-Landsteiner) antibody causing hemolysis after cold exposure (here, likely cooling in the dialysis circuit), with acrocyanosis and evidence of intravascular hemolysis (elevated LDH, free plasma hemoglobin), is diagnostic of paroxysmal cold hemoglobinuria.

3 Hemoglobinuria paroxística nocturna.

PNH is a different disease entirely (acquired GPI-anchor/complement-mediated hemolysis) despite the similarly-sounding name — it is not triggered by cold and does not involve an anti-P antibody.

4 Crioglobulinemia.

Cryoglobulinemia causes cold-induced vasculitis/hyperviscosity symptoms (purpura, arthralgia, renal disease) rather than this specific antibody-mediated hemolytic picture.

⭐ High-yield pearl

Anti-P (Donath-Landsteiner) antibody + cold exposure trigger = paroxysmal cold hemoglobinuria, not PNH. Paroxysmal cold hemoglobinuria is a rare autoimmune hemolytic anemia caused by a biphasic hemolysin (Donath-Landsteiner antibody) with anti-P specificity: the antibody binds red cells in the cold and fixes complement, causing hemolysis on rewarming — classically triggered by cold exposure, sometimes iatrogenic (like a cooled dialysis circuit).

#22 🖼️ requiere imagen 22

Mujer de 58 años acude a urgencias por dolor en la punta de los dedos de la mano. No tiene alergias conocidas, ni hábitos tóxicos. Entre los antecedentes explica tres abortos, una apendicetomía, sensación frecuente de reflujo retroesternal y, desde hace unos 5 años aproximadamente, presenta con la exposición al frío episodios de palidez en los dedos de ambas manos que cada vez se han hecho más intensos. A la vista de la imagen, ¿cuál de las siguientes actitudes se plantea realizar en primer lugar?

1 Solicitar una TC torácica.

Chest CT isn't the first step — you need to establish the underlying diagnosis (autoimmune serology) before pursuing organ-specific imaging.

2 Valoración de tratamiento quirúrgico por cirugía vascular.

Vascular surgery would only be considered for critical digital ischemia unresponsive to medical therapy — it's premature before establishing the diagnosis.

3 Determinación de ANA y anti-centrómero.

Correct. Progressive Raynaud phenomenon plus reflux symptoms (esophageal dysmotility) and a history of miscarriages raises suspicion for an underlying connective tissue disease (scleroderma-spectrum/CREST or possibly antiphospholipid syndrome) — the first, non-invasive step is autoimmune serology (ANA, anti-centromere).

4 Tratamiento vasodilatador con prostaglandinas iv.

IV prostaglandins are used for severe digital ischemia as treatment, but establishing the underlying diagnosis with serology comes first in a stable outpatient-type presentation.

⭐ High-yield pearl

Progressive Raynaud's + GERD + pregnancy losses = screen for scleroderma-spectrum disease with ANA/anti-centromere first. The combination of worsening Raynaud phenomenon, esophageal dysmotility (reflux), and pregnancy morbidity should prompt an autoimmune work-up — anti-centromere antibodies point toward limited systemic sclerosis (CREST), while other patterns might suggest antiphospholipid syndrome.

#23 🖼️ requiere imagen 23

En relación con un hombre de 74 años, que muestra alteraciones cognitivas y de la movilidad y en el cerebro neuronas con inclusiones citoplásmicas, como se observa en la imagen histológica, el diagnóstico más probable es:

1 Enfermedad de Alzheimer.

Alzheimer's disease is characterized histologically by extracellular amyloid plaques and intracellular neurofibrillary tangles (tau) — not the cytoplasmic inclusions described here.

2 Demencia senil.

'Senile dementia' isn't a specific histopathologic entity — it's a nonspecific, outdated umbrella term, not the answer being tested by this histology.

3 Enfermedad de Parkinson.

Correct. Cytoplasmic neuronal inclusions on histology, combined with cognitive AND motor impairment, describe Lewy bodies (aggregated alpha-synuclein) — the histologic hallmark of Parkinson's disease / Lewy body dementia.

4 Encefalitis viral.

Viral encephalitis would show inflammatory infiltrates and different clinical features (fever, acute onset) rather than this chronic cognitive/motor decline with cytoplasmic inclusions.

⭐ High-yield pearl

Cytoplasmic neuronal inclusions = Lewy bodies → Parkinson's disease / Lewy body dementia spectrum. Lewy bodies are eosinophilic, intracytoplasmic neuronal inclusions composed of aggregated alpha-synuclein; they are the histologic signature of both Parkinson's disease and dementia with Lewy bodies, distinct from the extracellular amyloid plaques and tau tangles of Alzheimer's disease.

#24 🖼️ requiere imagen 24

Mujer de 35 años con historia de dolor abdominal recurrente que coincide con la menstruación. Los hallazgos de la intervención quirúrgica requieren una resección intestinal. El estudio anatomopatológico se muestra en la imagen. ¿Cuál es el diagnóstico más probable?

1 Adenocarcimoma intestinal.

Intestinal adenocarcinoma wouldn't specifically flare in sync with the menstrual cycle — that timing pattern is the key clue against this.

2 Metástasis de adenocarcinoma de endometrio.

Endometrial adenocarcinoma metastasis would be a much rarer explanation and wouldn't typically present as cyclical pain over presumably years before diagnosis.

3 Colitis ulcerosa.

Ulcerative colitis causes chronic bloody diarrhea and mucosal inflammation, not focal bowel-wall lesions timed precisely with menstruation.

4 Endometriosis.

Correct. Cyclical abdominal pain that coincides with menstruation, with a bowel lesion requiring resection, is the classic presentation of intestinal (bowel-wall) endometriosis — ectopic endometrial tissue that bleeds and causes pain synchronized with the menstrual cycle.

⭐ High-yield pearl

Cyclical, menstruation-linked abdominal pain with a bowel lesion = intestinal endometriosis. Endometriosis can implant anywhere in the pelvis and occasionally into the bowel wall itself; because the ectopic endometrial tissue still responds to the hormonal cycle, symptoms characteristically flare with menstruation — a key historical clue that should trigger consideration of this diagnosis even at unusual sites.

#25 🖼️ requiere imagen 25

Hombre de 36 años con prácticas sexuales de riesgo. Presenta un cuadro de 4 días de evolución de lesiones cutáneas no pruriginosas (ver imagen). No ha tomado medicación previamente y no tiene antecedente de alergias farmacológicas. Se realiza serología para VIH que es negativa. La serología de sífilis antitreponema pallidum es positiva y RPR 1:32. Señale la respuesta correcta.

1 Se recomienda el análisis del líquido cefalorraquídeo.

Lumbar puncture is reserved for cases with neurologic, ophthalmic, or otic symptoms, or other specific risk indications — nothing here suggests neurosyphilis, so it's not routinely indicated.

2 La azitromicina oral es un tratamiento alternativo eficaz.

Azithromycin is not recommended as a reliable alternative due to widespread and increasing macrolide resistance in T. pallidum.

3 Se recomienda una valoración clínica y serológica (RPR) a los 6 y 12 meses después del tratamiento.

Correct. This is secondary syphilis (non-pruritic rash, positive treponemal test, RPR 1:32). After benzathine penicillin treatment, standard follow-up is clinical and serologic reassessment at 6 and 12 months to confirm an adequate titer decline.

4 Si los títulos de RPR permanecen positivos después de 12 meses está indicado administrar el tratamiento de nuevo.

Re-treatment decisions are based on the trend/magnitude of titer decline (or a rise), not simply persistence of any positive titer at 12 months — some patients have a slower but still adequate serologic response.

⭐ High-yield pearl

Secondary syphilis follow-up = repeat RPR at 6 and 12 months to confirm treatment response. Non-treponemal titers (RPR/VDRL) should fall at least four-fold by 6-12 months after adequate treatment of early syphilis; failure to do so (not simply 'still positive') suggests treatment failure or reinfection and prompts further evaluation, including consideration of neurosyphilis and HIV co-infection.

#26

Entre los cambios metabólicos que se observan en un paciente con resistencia a insulina existe:

1 Incremento de la expresión hepática de genes gluconeogénicos mediado por FOXO1 (forkhead box other) fosforilado.

This is backwards: insulin normally phosphorylates FOXO1, which inactivates it and excludes it from the nucleus, REDUCING gluconeogenic gene transcription. In insulin resistance, FOXO1 remains dephosphorylated (active), so 'phosphorylated FOXO1 increasing gluconeogenic genes' is incorrect.

2 Descenso en los niveles intracelulares de hexoquinasa 2 dependiente de insulina.

Insulin resistance impairs insulin's ability to induce/activate hexokinase II in muscle — but this describes a glucose-uptake defect, not the classic systemic metabolic signature being tested here.

3 Aumento de la glucogenólisis muscular, contribuyendo al incremento de la glucemia.

Skeletal muscle lacks glucose-6-phosphatase, so it cannot release free glucose into the bloodstream regardless of glycogenolysis — muscle glycogenolysis doesn't directly raise blood glucose the way hepatic glycogenolysis does.

4 Aumento en los niveles séricos de aminoácidos como leucina e isoleucina.

Correct. Insulin resistance is associated with a distinctive metabolomic signature that includes elevated circulating branched-chain amino acids (leucine, isoleucine, valine), which correlate with — and may mechanistically contribute to — insulin resistance.

⭐ High-yield pearl

Elevated branched-chain amino acids (leucine, isoleucine) are a recognized metabolic signature of insulin resistance. The BCAA-insulin resistance link (from metabolomics studies, e.g., Newgard et al.) is a modern, high-yield concept: elevated leucine/isoleucine/valine levels are seen early in the development of insulin resistance and type 2 diabetes, independent of obesity.

#27

La deficiencia de acil-CoA-deshidrogenasa provoca una de las siguientes alteraciones bioquímicas:

1 Disminución de ácidos dicarboxílicos.

This is backwards — MCAD deficiency causes INCREASED dicarboxylic acid excretion (dicarboxylic aciduria) from omega-oxidation compensating for blocked beta-oxidation, not decreased.

2 Aumento de la gluconeogénesis.

Fatty acid oxidation defects impair, not increase, gluconeogenesis/fasting tolerance — patients develop hypoketotic hypoglycemia during fasting, the opposite of increased gluconeogenesis.

3 Disminución de la ureagénesis.

Correct. Impaired beta-oxidation reduces acetyl-CoA/NADH available for N-acetylglutamate synthesis (an allosteric activator of carbamoyl phosphate synthetase I), impairing ureagenesis and causing secondary hyperammonemia — a key biochemical consequence of MCAD deficiency.

4 Aumento de carnitina libre.

Free carnitine is typically LOW (not increased) in MCAD deficiency because it gets consumed forming acylcarnitine conjugates with the accumulating fatty acid intermediates.

⭐ High-yield pearl

Fatty acid oxidation defects (e.g., MCAD deficiency) → hypoketotic hypoglycemia, dicarboxylic aciduria, secondary hyperammonemia, and LOW free carnitine. MCAD deficiency is the most common fatty acid oxidation disorder; during fasting/illness, patients cannot mobilize fat for energy, leading to hypoketotic hypoglycemia, and the impaired ureagenesis (via reduced N-acetylglutamate) causes a secondary hyperammonemia that can mimic a urea cycle disorder.

#28

Respecto a la técnica de exploración de la motilidad pupilar y sus reflejos indique la respuesta INCORRECTA:

1 El reflejo de la visión próxima se explora con una linterna que se enfoca sobre las pupilas de forma alternativa.

Incorrect statement (so this is the answer). Swinging a light alternately between the two pupils is how you test for a relative afferent pupillary defect (Marcus Gunn pupil) — not the near/accommodation reflex, which is tested by having the patient shift gaze from a distant to a near target.

2 El signo pupilar de Marcus Gunn o defecto pupilar aferente relativo está presente en enfermedades del nervio óptico y enfermedades retinianas no extensas.

This is a true statement — RAPD occurs with optic nerve disease or non-extensive (asymmetric) retinal disease.

3 El reflejo fotomotor consensuado está afectado cuando el daño implica la vía eferente vehiculada por el nervio motor ocular común.

Also true — a consensual light reflex defect implies a lesion in the efferent pathway carried by CN III (oculomotor nerve).

4 La anisocoria que aumenta en condiciones de oscuridad mostrando una pupila más miótica se debe a que hay un trastorno en el sistema simpático.

Also true — anisocoria that worsens in the dark (the smaller pupil failing to dilate) points to a sympathetic lesion (Horner syndrome).

⭐ High-yield pearl

Swinging flashlight test = tests for RAPD (afferent pathway), not the near/accommodation reflex. Don't confuse the swinging flashlight test (afferent pathway assessment for RAPD) with the near reflex triad (miosis, accommodation, convergence), which is elicited by shifting fixation from far to near — these are two entirely different parts of the pupillary exam.

#29

En relación con el proceso de envejecimiento, respecto a los principales cambios morfológicos de los aparatos y sistemas, indique la respuesta INCORRECTA:

1 En el aparato respiratorio, calcificación de los cartílagos traqueales.

This is a true, recognized change of aging — tracheal cartilage calcification does occur.

2 En el sistema nervioso, aumento del tamaño de los surcos interhemisféricos y de los ventrículos cerebrales.

Also true — cerebral atrophy with enlarged sulci and ventricles is a classic aging change on imaging.

3 En el aparato cardiovascular, reducción en el número de células marcapaso.

Also true — a reduced number of sinoatrial pacemaker cells contributes to age-related sinus node dysfunction.

4 En el sistema nefrourológico, reducción del tejido mesangial.

Incorrect statement (so this is the answer). Normal kidney aging is characterized by an INCREASE (not a reduction) in mesangial matrix and glomerulosclerosis, along with declining nephron number and GFR — the opposite of what this option claims.

⭐ High-yield pearl

Aging kidneys develop MORE mesangial matrix/sclerosis and fewer nephrons — not less mesangial tissue. Renal aging involves progressive nephron loss, glomerulosclerosis (with increased mesangial matrix), and declining GFR — clinically relevant when dosing renally-cleared medications in elderly patients even with a 'normal' creatinine.

#30

La utilización baja de energía por el músculo liso es fundamental para el gasto de energía corporal (órganos como los intestinos, la vejiga urinaria o la vesícula biliar mantienen una contracción muscular tónica casi indefinidamente). A este respecto, señale la afirmación correcta:

1 La disposición física de los filamentos de miosina y actina es similar a la del músculo esquelético.

Smooth muscle lacks the organized sarcomeric arrangement of skeletal muscle — its actin/myosin filament architecture is quite different (no visible striations), so this statement is false.

2 En esa contracción, es fundamental la lentitud de la unión y separación de los puentes cruzados entre los filamentos de actina y miosina.

Correct. Smooth muscle sustains tonic contraction at low energy cost via the 'latch state' — actin-myosin cross-bridges attach and detach very slowly, allowing force maintenance with minimal ATP turnover.

3 La fuerza máxima de contracción es con frecuencia menor que la que se produce en el músculo esquelético.

Smooth muscle can actually generate comparable or even greater maximal force per unit cross-sectional area than skeletal muscle — this statement understates its capability.

4 La contracción prolongada exige que la excitación de las fibras musculares se mantenga mientras lo haga esa contracción.

Unlike skeletal muscle, smooth muscle tonic contraction does NOT require continuous sustained electrical excitation — the latch state allows force maintenance even after excitation has ceased.

⭐ High-yield pearl

Smooth muscle's 'latch state' — slow cross-bridge cycling — lets it sustain tone with very little energy, unlike skeletal muscle. The latch state explains why organs like the bladder, gallbladder, and GI sphincters can maintain tonic tension for long periods without fatiguing or consuming large amounts of ATP — a key physiologic distinction from fast, energy-hungry skeletal muscle contraction.

#31

En relación con el control químico de la respiración en condiciones fisiológicas señale la afirmación INCORRECTA:

1 Los quimiorreceptores carotídeos y aórticos detectan especialmente cambios en la presión parcial de O2 en la sangre.

True statement — peripheral chemoreceptors (carotid/aortic bodies) mainly sense PaO2 changes.

2 Los quimiorreceptores carotídeos y aórticos reciben un flujo arterial muy elevado por lo que se consideran expuestos en todo momento a sangre arterial.

Also true — these chemoreceptors have an extremely high blood flow relative to their mass, keeping them constantly exposed to fresh arterial blood.

3 Los quimiorreceptores centrales detectan fundamentalmente cambios en la concentración de H+ (procedente sobre todo de la disociación de CO2 y H2O).

Also true — central chemoreceptors respond mainly to CSF H+ derived from CO2 diffusing across the blood-brain barrier.

4 El efecto estimulador de la ventilación del CO2 se mantiene sin atenuación en los primeros días.

Incorrect statement (so this is the answer). With chronic hypercapnia over days, renal and CSF bicarbonate compensation blunts the central chemoreceptor response to CO2 — the ventilatory drive is NOT sustained unattenuated, which is why chronic CO2 retainers can become relatively dependent on hypoxic drive.

⭐ High-yield pearl

Central chemoreceptor sensitivity to CO2 blunts over days of chronic hypercapnia due to renal/CSF bicarbonate compensation. This is clinically relevant in COPD patients with chronic CO2 retention: their blunted central response to CO2 means hypoxic drive (via peripheral chemoreceptors) becomes relatively more important — the classical (if oversimplified) rationale behind caution with high-flow oxygen in some chronic hypercapnic patients.

#32

En un paciente diagnosticado de una neoplasia maligna de nasofaringe que presenta dolor y edema orbitario, neuropatía de los pares craneales III, IV y VI, y neuropatía de la rama V1 del V par craneal, indique qué estructura es más probable que se encuentre infiltrada:

1 Seno cavernoso.

Correct. Combined palsies of CN III, IV, VI, plus the ophthalmic division (V1) of CN V, together with orbital pain/edema, define cavernous sinus syndrome — all of these nerves pass through or alongside the cavernous sinus.

2 Hipófisis.

Pituitary (hypophyseal) lesions classically cause visual field defects (bitemporal hemianopia from chiasm compression) and endocrine dysfunction, not this specific combination of ocular motor + V1 palsies.

3 Agujero yugular.

The jugular foramen syndrome involves CN IX, X, and XI (not III, IV, VI, V1) — a different cranial nerve combination entirely.

4 Fosa pterigopalatina.

The pterygopalatine fossa relates to branches like V2 (maxillary) and autonomic fibers, not the CN III/IV/VI/V1 combination described.

⭐ High-yield pearl

CN III + IV + VI + V1 palsies together = cavernous sinus syndrome. The cavernous sinus is traversed by CN III, IV, VI, and V1 (plus the internal carotid artery), making it a key anatomic 'choke point' — any mass lesion invading it (tumor, thrombosis, aneurysm) can produce this characteristic multi-nerve palsy pattern with orbital pain/edema.

#33

Niña de 7 años con una sospecha de anemia de Fanconi. ¿Cuál de las siguientes manifestaciones clínicas NO se ajusta a los rasgos típicos de esta enfermedad?

1 Anomalías pigmentarias.

This is a true, classic feature of Fanconi anemia — café-au-lait spots and other pigmentary changes are common.

2 Anomalías renales.

Also a recognized feature — renal malformations are part of the classic constellation.

3 Anomalías esqueléticas.

Also true — skeletal anomalies (especially radial ray/thumb defects) are classic.

4 Estatura alta.

Incorrect fit (so this is the answer). Fanconi anemia is classically associated with SHORT stature, not tall stature — this is the outlier that doesn't belong.

⭐ High-yield pearl

Fanconi anemia = short stature + skin pigment changes + thumb/radial and renal anomalies + bone marrow failure. Fanconi anemia is a DNA-repair disorder (an inherited bone marrow failure syndrome) presenting with short stature, skeletal anomalies (classically radial ray defects), pigmentary skin changes, and renal malformations, progressing to marrow failure and increased malignancy risk — tall stature has no place in this picture.

#34

La exploración ecográfica de una mujer gestante de 26 semanas muestra hallazgos consistentes con osteogénesis imperfecta tipo II (gen COL1A1/COL1A2). La paciente tuvo un embarazo previo con la misma patología. Ni ella ni su pareja tienen manifestaciones clínicas de osteogénesis imperfecta. ¿Cuál de las siguientes es la explicación más probable para la recurrencia?

1 Herencia autosómica recesiva.

OI type II is typically autosomal dominant (from COL1A1/COL1A2), not recessive, so this doesn't fit the known inheritance pattern.

2 Mutación de novo.

A fresh de novo mutation would be extremely unlikely to recur identically in a second pregnancy — this doesn't explain the recurrence pattern seen here.

3 Penetrancia incompleta.

Incomplete penetrance would mean carriers sometimes show no symptoms, but wouldn't specifically explain how phenotypically completely normal parents have TWO affected pregnancies.

4 Mosaicismo germinal.

Correct. Germline (gonadal) mosaicism — where a mutation is present in a subset of a parent's germ cells but not in their somatic (body) tissue — explains how clinically unaffected parents can have recurrent offspring with an autosomal dominant condition.

⭐ High-yield pearl

Recurrence of an autosomal dominant disease in unaffected parents = germline mosaicism. Germline mosaicism should be suspected whenever a 'sporadic' autosomal dominant condition recurs in siblings born to unaffected parents — it has important implications for genetic counseling, since the recurrence risk is higher than the near-zero risk expected from a truly de novo mutation.

#35

Las vacunas contra el neumococo recomendadas para prevenir la enfermedad neumocócica en personas mayores de 65 años y en pacientes inmunocomprometidos pueden estar constituidas por polisacáridos del neumococo purificados (PPV23) o polisacáridos conjugados a proteínas (PCV15 o PCV20). Desde una perspectiva inmunológica las vacunas conjugadas:

1 No generan memoria inmunológica.

This is backwards — conjugate vaccines are specifically designed to generate strong, durable immune MEMORY, unlike plain polysaccharide vaccines.

2 Activan una respuesta inmunitaria T-dependiente (o timo-dependiente).

Correct. Conjugating the polysaccharide antigen to a carrier protein converts the response from T-independent to T-dependent, engaging T-helper cells and enabling germinal center reactions.

3 No activan el proceso de hipermutación somática.

Also backwards — because they engage T-dependent germinal center reactions, conjugate vaccines DO activate somatic hypermutation.

4 No inducen cambio de isotipo.

Also backwards — T-dependent responses DO induce isotype (class) switching, another feature enabled by the conjugate design.

⭐ High-yield pearl

Conjugate vaccines (PCV) work by converting a T-independent polysaccharide response into a T-dependent one, generating memory and class-switched antibody. This is why conjugate vaccines (like PCV13/15/20) are preferred over plain polysaccharide vaccines (PPV23) in young children (whose immune systems respond poorly to T-independent antigens) and why they provide more durable protection with booster/memory responses in adults too.

#36

El paso de autoanticuerpos de la madre al feto a través de la placenta puede asociarse a la aparición de enfermedades autoinmunes en el recién nacido. Señale cuál de las parejas Enfermedad – Autoanticuerpo es INCORRECTA:

1 Pénfigo vulgar – Anticuerpos antidesmogleina 3.

This pairing is correct — transplacental anti-desmoglein 3 antibodies cause neonatal pemphigus vulgaris.

2 Bloqueo cardíaco congénito – Anticuerpos anti Ro y anti-La.

Also correct — anti-Ro/SSA and anti-La/SSB antibodies cause congenital heart block.

3 Miastenia gravis – Anticuerpos anti receptor de la acetilcolina.

Also correct — anti-AChR antibodies cause transient neonatal myasthenia gravis.

4 Lupus eritematoso neonatal – Anticuerpos antiSm.

Incorrect pairing (so this is the answer). Neonatal lupus (including congenital heart block and the classic rash) is mediated by anti-Ro/SSA and anti-La/SSB antibodies — NOT anti-Sm, which is more specific for SLE itself but isn't the mediator of neonatal lupus.

⭐ High-yield pearl

Neonatal lupus (including congenital heart block) is mediated by anti-Ro/SSA and anti-La/SSB — NOT anti-Sm. Remember that anti-Ro/La are the culprits behind both the neonatal lupus rash AND congenital heart block, making them the antibodies to screen for in a pregnant woman with SLE/Sjögren's, regardless of whether anti-Sm is also present.

#37

Mutaciones en el gen Btk pueden causar una inmunodeficiencia primaria que cursa con la disminución drástica o ausencia de inmunoglobulinas en la sangre periférica (agammaglobulinemia). En relación al estudio de los pacientes con esta agammaglobulinemia, ¿cuál de las siguientes afirmaciones es cierta?

1 Es una enfermedad autosómica recesiva.

X-linked agammaglobulinemia is X-linked, not autosomal recessive — the gene name (BTK, on the X chromosome) is the giveaway.

2 El porcentaje de linfocitos que expresan CD19 o CD20 (linfocitos B) en sangre periférica está dentro de los límites normales.

Btk's developmental block in the bone marrow means peripheral B cells (CD19+/CD20+) are markedly REDUCED or absent, not within normal limits.

3 El nivel de IgG en suero disminuye paulatinamente desde el nacimiento hasta resultar indetectable.

Correct. Because maternal IgG crosses the placenta and provides passive protection at birth, affected infants often appear normal initially, with serum IgG progressively falling as maternal antibody is catabolized over the first months of life, eventually becoming undetectable — the classic natural history.

4 La expresión de la proteína Btk en monocitos es normal.

Btk is also expressed in monocytes and would show abnormal expression/function there too in this disease — it's not restricted to (or normal outside) B cells.

⭐ High-yield pearl

X-linked agammaglobulinemia: normal at birth (maternal IgG), then progressive IgG decline to undetectable as maternal antibody wanes, with absent peripheral B cells. This natural history explains why XLA typically presents with recurrent bacterial infections starting around 4-6 months of age — once maternal IgG has waned and the infant's own B-cell-deficient immune system cannot compensate.

#38

Hombre de 20 años que, tras ingesta de gambas, presenta de forma prácticamente inmediata prurito palmoplantar, sensación de nudo en la garganta y ronquera, mareo, sensación de inestabilidad y debilidad intensa. Entre sus antecedentes destaca cuadro de edema laríngeo por alergia a las lentejas al año de edad. No refiere alergia conocida a otros alimentos, tampoco reacciones adversas a fármacos ni picadura de insectos. Entre los antecedentes familiares tiene un hermano con rinitis alérgica leve intermitente por alergia a pólenes. ¿Cuál debe ser el tratamiento inicial de forma urgente?

1 Hidrocortisona 500 mg IV y dexclorfeniramina 5 mg IV.

Corticosteroids and antihistamines are adjunctive treatments, not first-line for acute anaphylaxis — giving these first/alone delays the life-saving intervention.

2 Adrenalina 0,3-0,5 mL IV.

IV epinephrine is reserved for refractory anaphylaxis or cardiac arrest under continuous cardiac monitoring, due to the risk of dangerous arrhythmias — it is NOT the first-dose route.

3 Adrenalina 0,3-05 mL IM.

Correct. This is anaphylaxis (rapid-onset pruritus, laryngeal symptoms/hoarseness, dizziness, severe weakness after a known food trigger). First-line, first-dose treatment is intramuscular epinephrine (0.3-0.5 mg IM into the anterolateral thigh).

4 Metilprednisolona 40 mg IM y desclorfeniramina 5 mg IV.

Same issue as option 1 — steroids/antihistamines are adjuncts, not the urgent first-line treatment for anaphylaxis.

⭐ High-yield pearl

Anaphylaxis first-line treatment is IM epinephrine — not IV, not steroids/antihistamines first. IM epinephrine into the anterolateral thigh (vastus lateralis) achieves faster, more reliable absorption than deltoid IM or subcutaneous injection, and should be given immediately upon recognizing anaphylaxis — delay is a major cause of preventable death.

#39

Hombre de 40 años sin antecedentes patológicos de interés, residente en una zona de interior de la península ibérica, que presentó cuadro de urticaria aguda por sensibilización a Anisakis simplex tras haber ingerido larvas vivas en unos boquerones en vinagre. El cuadro descrito le ocurrió hace más de 6 meses. Aporta prueba cutánea e IgE específica positiva frente a dicho parásito. En relación a la ingesta de pescados, ¿qué pauta de las que se indican a continuación debe seguir?

1 Puede comer pescados y mariscos sin ningún tipo de precaución dado que han transcurrido más de 6 meses de la ingesta.

Sensitization to Anisakis doesn't wane simply because 6 months have passed — precautions must continue indefinitely once IgE-sensitized.

2 No puede ingerir ningún tipo de pescado.

Total fish avoidance is unnecessarily restrictive — the goal is avoiding live larvae, not fish itself.

3 Puede comer pescado cocinado a 45ºC.

45°C is not a sufficiently high cooking temperature to reliably kill Anisakis larvae — proper cooking needs to reach well above this.

4 Puede comer pescado previamente congelado a -20ºC durante 72 horas en el domicilio o pescado congelado industrial.

Correct. Once sensitized, a patient must avoid live-larvae exposure indefinitely, but properly killing the larvae by adequate freezing (household freezing at -20°C for several days, or industrial blast-freezing) renders fish safe to eat.

⭐ High-yield pearl

Anisakis-sensitized patients don't have to give up fish — adequate freezing (or thorough cooking at a proper temperature) kills the larvae and prevents reactions. This is a common source of confusion: the allergy is to the live parasite (or its residual proteins), not fish per se, so freezing/cooking protocols that kill Anisakis are the mainstay of prevention, not permanent total fish avoidance.

#40

La medida adecuada para estimar el riesgo individual de enfermar es:

1 La incidencia acumulada.

Correct. Cumulative incidence (the proportion of an at-risk population developing disease over a defined period) directly represents the average probability — the individual risk — that a person in that population will develop the disease over that period.

2 La densidad de incidencia.

Incidence density (rate) uses person-time in the denominator and represents a rate, not directly an individual's probability of disease over a fixed period.

3 La prevalencia puntual.

Point prevalence measures existing disease burden at a moment in time, not the risk of developing new disease.

4 El riesgo relativo.

Relative risk is a comparative (ratio) measure between two groups' risks — useful for etiologic strength, but it isn't itself an absolute individual risk estimate.

⭐ High-yield pearl

Cumulative incidence = individual probability of developing disease over a time period. This is a fundamental epidemiology distinction: cumulative incidence (a proportion/probability, unitless) estimates individual risk, while incidence density (a rate, with units of 1/time) is used for dynamic populations and doesn't map directly onto a single person's probability.

#41

Al finalizar el periodo de seguimiento en el estudio PREDIMET, el 3,8% de los individuos asignados a dieta mediterránea presentaron algún tipo de evento cardiovascular, frente al 4,4% de eventos ocurridos en el grupo control. ¿Cuál es el número necesario de pacientes a tratar (NNT) con dieta mediterránea para evitar un evento cardiovascular?

1 26.

This would correspond to an absolute risk reduction of about 3.8% (1/26 ≈ 3.8%), which doesn't match the ARR calculated from the given data (0.6%).

2 60.

This would correspond to an ARR of about 1.7% (1/60), again not matching the actual 0.6% ARR from these numbers.

3 80.

This would correspond to an ARR of about 1.25% (1/80), still not matching the calculated 0.6% ARR.

4 167.

Correct. Absolute risk reduction (ARR) = 4.4% - 3.8% = 0.6% = 0.006. NNT = 1/ARR = 1/0.006 ≈ 167.

⭐ High-yield pearl

NNT = 1 / Absolute Risk Reduction. Always convert percentages to decimals before dividing, and double-check by confirming that a smaller ARR produces a larger (not smaller) NNT — a common source of calculation errors under exam time pressure.

#42

En evaluación económica de intervenciones sanitarias, un estudio que compare los costes alternativos de dos intervenciones frente a sus resultados de salud expresados en años ajustados por calidad o años de vida ajustados por discapacidad se denomina:

1 Análisis coste-beneficio.

Cost-benefit analysis expresses health outcomes in monetary terms (translating health gains into dollars), not QALYs/DALYs.

2 Análisis coste-efectividad.

Cost-effectiveness analysis (in the general/narrow sense) uses natural clinical units (life-years gained, cases prevented), not utility-weighted measures like QALYs.

3 Análisis coste-utilidad.

Correct. Cost-utility analysis specifically expresses health outcomes in utility-weighted units such as QALYs or DALYs, allowing comparison across very different interventions/diseases.

4 Análisis de minimización de costes.

Cost-minimization analysis assumes the outcomes of the two interventions are equivalent and compares only their costs — it doesn't use QALYs/DALYs at all.

⭐ High-yield pearl

QALYs/DALYs as the outcome measure = cost-utility analysis. Cost-utility analysis is technically a specific subtype of cost-effectiveness analysis, distinguished by its use of a utility-weighted, generic health outcome measure (QALY/DALY) that allows cross-disease comparisons (e.g., comparing a cancer drug to a hip replacement program) on a common scale.

#43

Señala la opción INCORRECTA respecto a la enfermedad meningocócica:

1 El mecanismo de transmisión es por gotas.

True statement — meningococcal transmission is by respiratory droplets.

2 Se dispone de vacunas efectivas únicamente para la prevención de 4 subtipos de meningococo.

Incorrect statement (so this is the answer). There are effective vaccines covering more than just 4 serogroups — the tetravalent ACWY conjugate vaccine covers 4 serogroups, AND a separate vaccine exists for serogroup B, so overall vaccine coverage spans 5 serogroups, not only 4.

3 La vacuna frente a meningococo tipo B está incluida en el calendario sistemático de inmunizaciones del Sistema Nacional de Salud.

This is a true statement in the current Spanish national immunization schedule context — MenB vaccination has been incorporated into the systematic schedule.

4 Ante un contacto de riesgo con un paciente con meningitis meningocócica, la vacunación del contacto no debe ser la primera estrategia de profilaxis postexposición.

Also true — chemoprophylaxis (antibiotics), not vaccination, is the primary post-exposure strategy for close contacts, since vaccine-induced immunity takes time to develop.

⭐ High-yield pearl

Meningococcal vaccines now cover 5 serogroups overall (ACWY conjugate + separate MenB vaccine). Chemoprophylaxis with antibiotics (e.g., rifampin, ciprofloxacin, or ceftriaxone) remains the cornerstone of post-exposure management for close contacts of meningococcal disease, given the rapid antibody response needed versus the slower buildup of vaccine-induced immunity.

#44

Se diagnostica de varicela a un niño de 8 años. Su madre está embarazada de 32 semanas y se le solicita una serología en la que se observan anticuerpos de tipo IgG frente a varicela por debajo de los niveles protectores y niega haber padecido la enfermedad en el pasado. ¿Cuál es la actitud recomendada con la gestante sabiendo que han pasado 3 días desde el inicio de la exposición?

1 Administrar una dosis de la vacuna frente a varicela.

The varicella vaccine is a live-attenuated vaccine and is contraindicated during pregnancy — this option should never be chosen for a pregnant patient.

2 Forzar la terminación del embarazo para poder vacunarla.

There is no indication whatsoever to terminate a pregnancy for this reason — this option is both unnecessary and inappropriate.

3 Es tarde para plantear una estrategia de profilaxis post-exposición.

Post-exposure prophylaxis with VZIG is effective when given up to about 10 days after exposure — 3 days falls well within this window, so it is NOT too late.

4 Administrar gammaglobulinas polivalentes o hiperinmunes.

Correct. A susceptible (non-immune) pregnant woman exposed to varicella should receive varicella-zoster immune globulin (VZIG) as post-exposure prophylaxis, ideally as soon as possible and still effective within the ~10-day window — 3 days fits comfortably within this.

⭐ High-yield pearl

Susceptible pregnant woman + varicella exposure = VZIG (not the live vaccine), effective up to about 10 days post-exposure. VZIG reduces the severity of maternal varicella and the risk of complications, though it does not fully guarantee prevention of fetal varicella syndrome — timing (within the exposure window) is the critical factor for its effectiveness.

#45

En un metaanálisis, el riesgo relativo estimado para la asociación causal entre el uso de mascarilla y la incidencia de SARS-CoV-2 fue de 0,47. ¿Cuál es la interpretación correcta de este resultado?

1 La incidencia de SARS-CoV-2 se reduce un 47% cuando la población usa mascarilla.

This is a common misinterpretation — an RR of 0.47 does NOT mean a flat 47% reduction; the actual relative risk reduction is 1 - 0.47 = 53%, not 47%.

2 No usar mascarilla aumenta un 53% el riesgo de infección por SARS-CoV-2.

This reverses the reference group incorrectly and mixes up the framing — the correct relative risk reduction (53%) applies to what happens when a non-mask-wearing population starts wearing masks, not phrased as 'not wearing increases risk by 53%' in this direction.

3 El uso de mascarilla podría evitar 47 de cada 100 casos de SARS-CoV-2 que se dan en personas que no la usan.

This restates the same 47% error in different words ('47 of 100 cases avoided') rather than the correct 53% relative risk reduction.

4 La incidencia de SARS-CoV-2 en la población que no usa mascarilla se reduciría un 53% si la utilizara.

Correct. RR = 0.47 means Relative Risk Reduction = 1 - RR = 0.53, i.e., a 53% reduction in risk associated with mask use relative to the non-mask-using population's own baseline risk.

⭐ High-yield pearl

RR of 0.47 → Relative Risk Reduction = 1 − RR = 53%, not 47%. This is a very common exam trap: people intuitively subtract the RR from 100% incorrectly or misassign which group's baseline the percentage refers to. Always explicitly calculate 1 − RR and state clearly whose baseline risk the reduction is relative to.

#46

Hombre de 79 años de edad con antecedentes de hipertensión arterial, hiperuricemia y artrosis que acude a urgencias por posible reacción adversa farmacológica. No refiere antecedentes alergológicos de interés. Después de una excursión en barco sin protección solar presenta un cuadro cutáneo agudo facial, principalmente en párpados superiores e inferiores, consistentes en eritema y edema intenso bilateral. El paciente estaba realizando tratamiento médico de forma habitual con hidroclorotiazida 25 mg, amlodipino 5 mg, atorvastatina 10 mg y apixaban 5 mg. ¿Cuál de los cuatro fármacos descritos es más probable que sea el responsable de una posible reacción de fotosensibilidad?

1 Hidroclorotiazida.

Correct. Thiazide diuretics (hydrochlorothiazide) are among the most classic and common causes of drug-induced photosensitivity/phototoxic reactions, particularly after significant sun exposure, presenting as an exaggerated sunburn-like eruption in sun-exposed areas.

2 Amlodipino.

Amlodipine is much less commonly implicated in photosensitivity reactions compared to thiazides.

3 Atorvastatina.

Atorvastatin is not a classic cause of photosensitivity reactions.

4 Apixaban.

Apixaban (a factor Xa inhibitor) is not associated with photosensitivity — its main adverse effect concern is bleeding.

⭐ High-yield pearl

Thiazide diuretics are a top cause of drug-induced photosensitivity reactions. Always ask about recent sun exposure in a patient on a thiazide who presents with an acute facial/exposed-skin eruption — phototoxic reactions can occur even years into stable thiazide therapy, triggered simply by an unusually intense sun exposure episode.

#47

¿Con cuál de estos fármacos administrados en monoterapia es necesario realizar un ecocardiograma antes de su inicio?

1 Trastuzumab.

Correct. Trastuzumab (anti-HER2 monoclonal antibody) carries a well-known risk of cardiotoxicity (reversible LV dysfunction/heart failure), so a baseline echocardiogram (and serial monitoring) is mandatory before and during treatment.

2 Tamoxifeno.

Tamoxifen's main monitoring concerns are endometrial changes and thromboembolism, not cardiac function — no baseline echo requirement.

3 Paclitaxel.

Paclitaxel's classic toxicities are peripheral neuropathy and hypersensitivity reactions, not cardiotoxicity requiring baseline echo.

4 Docetaxel.

Docetaxel's classic toxicities are neutropenia and fluid retention, not the cardiotoxicity profile that mandates baseline echocardiography.

⭐ High-yield pearl

Trastuzumab requires a baseline (and serial) echocardiogram to monitor LVEF due to cardiotoxicity risk. Trastuzumab-induced cardiotoxicity is usually reversible with drug discontinuation (unlike anthracycline-induced cardiotoxicity, which is often permanent) — but this still requires proactive monitoring with serial LVEF assessments throughout treatment.

#48

La inducción de secuencia rápida en la anestesia general es:

1 Método de inducción anestésica utilizado cuando existe riesgo de regurgitación gástrica y aspiración pulmonar.

Correct. Rapid sequence induction (RSI) is specifically designed to minimize the time between loss of protective airway reflexes and securing the airway with a cuffed endotracheal tube, precisely to reduce aspiration risk in at-risk patients (full stomach, pregnancy, bowel obstruction, emergency surgery).

2 Método de inducción anestésica realizado exclusivamente con halogenados.

RSI is not done exclusively with inhalational (halogenated) agents — it typically uses rapid-onset IV induction agents plus a fast-acting paralytic.

3 Procedimiento anestésico que requiere la ventilación del paciente con presión positiva.

RSI specifically tries to AVOID positive-pressure mask ventilation before intubation (to avoid gastric insufflation and regurgitation risk), so this statement is the opposite of standard RSI technique.

4 Método de inducción anestésica utilizado habitualmente para la realización del procedimiento quirúrgico programado.

RSI is reserved for at-risk patients (full stomach/aspiration risk), not the routine technique for elective, fasted, scheduled surgery.

⭐ High-yield pearl

Rapid sequence induction = airway-securing technique to minimize aspiration risk in patients with a 'full stomach.' Key features of RSI include pre-oxygenation, avoiding bag-mask ventilation (or using it very gently if needed), rapid-onset induction agent plus paralytic, and often cricoid pressure (though its benefit is debated) — all aimed at minimizing the vulnerable unprotected-airway window.

#49

Señale la actitud correcta ante un paciente en edad infantil que refiere antecedente de traumatismo facial no tratado hace 3 años y que presenta limitación progresiva de la apertura oral y desviación del mentón hacia un lado.

1 Debe descartarse la existencia de una fractura antigua tipo Lefort-1.

A Le Fort I fracture involves the maxilla, not the mandibular condyle/TMJ — it wouldn't produce this specific pattern of progressive trismus with chin deviation.

2 Debe realizarse un estudio mediante tomografía computarizada para descartar una displasia fibrosa.

Fibrous dysplasia is possible in the differential of jaw lesions generally, but doesn't specifically fit the classic old-trauma-to-condyle-then-progressive-trismus story as well as the answer below.

3 Debe descartarse el diagnóstico de osteocondroma del cóndilo mandibular.

Osteochondroma of the mandibular condyle is a less common consideration and doesn't match the specific old-trauma history and progressive symptom pattern as precisely.

4 Debe descartarse el diagnóstico de anquilosis témporo-mandibular.

Correct. Progressive limitation of mouth opening (trismus) with chin deviation toward the affected side, following an untreated facial/mandibular condylar trauma years earlier in a child, is the classic presentation of TMJ ankylosis — a recognized late complication of pediatric condylar fractures.

⭐ High-yield pearl

Progressive trismus + chin deviation after old childhood condylar trauma = TMJ ankylosis. Children have high bone remodeling/fibrosis potential, so an untreated condylar fracture can progressively fuse (bony or fibrous ankylosis) over months to years, producing exactly this pattern of worsening trismus and facial asymmetry (chin deviation toward the affected, restricted side).

#50

Respecto al colgajo DIEP (Deep inferior epigastric perforator), señale la respuesta INCORRECTA:

1 Se trata de un colgajo basado en vasos perforantes que puede ser usado como colgajo libre o como colgajo pediculado.

True statement — the DIEP flap is a perforator flap that can be used as free or (less commonly) pedicled tissue.

2 Está irrigado por ramas de la arteria circunfleja femoral lateral.

Incorrect statement (so this is the answer). The DIEP flap is named for and vascularized by perforators of the DEEP INFERIOR EPIGASTRIC artery (a branch of the external iliac artery) — not the lateral circumflex femoral artery, which supplies an entirely different flap (anterolateral thigh).

3 Puede utilizarse para reconstrucción mamaria.

True statement — DIEP is a workhorse flap for autologous breast reconstruction.

4 Los vasos perforantes musculocutáneos atraviesan el músculo recto del abdomen antes de irrigar la piel del colgajo.

Also true — its musculocutaneous perforators characteristically pass through the rectus abdominis muscle before reaching the overlying skin/fat, which is why sparing the muscle (vs. the older TRAM flap) is the key advantage of DIEP.

⭐ High-yield pearl

DIEP flap = based on the deep inferior epigastric artery (not the lateral circumflex femoral artery). The similar-sounding names (deep inferior epigastric vs. lateral circumflex femoral) are a classic exam trap — remember DIEP is an abdominal-donor-site flap for breast reconstruction, distinct from thigh-based flaps like the ALT flap (lateral circumflex femoral system).

Resultado del examen