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MDCN Assessment practice questions

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Question 1Medicine

A 58-year-old man presents with sudden-onset severe tearing chest pain radiating to the back. Blood pressure is 180/100 mmHg in the right arm and 140/85 mmHg in the left arm. Which is the most appropriate initial imaging investigation for suspected acute aortic dissection in a haemodynamically stable patient?

  1. Plain chest radiograph
  2. Transthoracic echocardiography
  3. Exercise treadmill testing
  4. Contrast-enhanced CT angiography of the aorta Correct answer.

Explanation

Contrast-enhanced CT angiography is the first-line investigation for stable patients with suspected acute aortic dissection because it rapidly demonstrates the intimal flap, extent of dissection, and involvement of branch vessels. Inter-arm blood pressure difference and tearing pain are classic features that warrant urgent aortic imaging.

Question 2Medicine

A 24-year-old woman has fatigue, palpitations, and heat intolerance. Examination shows a diffuse goitre, tremor, and warm moist skin. TSH is suppressed and free T4 is elevated. Which antibody is most characteristically associated with this condition?

  1. Anti-thyroglobulin antibody
  2. Anti-voltage-gated calcium channel antibody
  3. Thyroid-stimulating immunoglobulin Correct answer.
  4. Anti-thyroid peroxidase antibody

Explanation

Graves' disease is caused by thyroid-stimulating immunoglobulins that activate the TSH receptor, producing hyperthyroidism and diffuse goitre. Anti-TPO and anti-thyroglobulin antibodies are seen in Hashimoto's thyroiditis and are not specific for Graves' disease.

Question 3Medicine

A 65-year-old man with chronic obstructive pulmonary disease has an arterial blood gas showing pH 7.32, PaCO2 62 mmHg, and bicarbonate 31 mmol/L. Which acid-base disturbance best describes these findings?

  1. Mixed respiratory and metabolic acidosis
  2. Metabolic alkalosis with respiratory compensation
  3. Chronic respiratory acidosis with metabolic compensation Correct answer.
  4. Acute respiratory acidosis without metabolic compensation

Explanation

A raised PaCO2 with a raised bicarbonate and only mildly reduced pH indicates chronic respiratory acidosis with renal retention of bicarbonate as metabolic compensation. In acute respiratory acidosis, bicarbonate would be only slightly elevated and pH would be lower.

Question 4Medicine

A 30-year-old woman reports episodic pounding headaches with palpitations and sweating. During an attack her blood pressure is 210/120 mmHg. Plasma metanephrines are markedly elevated. Which tumour is the most likely cause?

  1. Adrenal cortical adenoma
  2. Pituitary adenoma
  3. Phaeochromocytoma Correct answer.
  4. Parathyroid adenoma

Explanation

Episodic headache, palpitations, sweating, and severe hypertension with elevated plasma metanephrines are the classic presentation of phaeochromocytoma, a catecholamine-secreting tumour of the adrenal medulla. Biochemical confirmation with metanephrines is the recommended initial test.

Question 5Medicine

A 72-year-old man has resting tremor, bradykinesia, and cogwheel rigidity. Which pathological finding is most characteristic of the underlying neurodegenerative disorder?

  1. Loss of anterior horn cells in the spinal cord
  2. Amyloid plaques and neurofibrillary tangles
  3. Loss of dopaminergic neurons in the substantia nigra pars compacta Correct answer.
  4. Demyelination of the optic nerve

Explanation

Parkinson's disease results from degeneration of dopaminergic neurons in the substantia nigra pars compacta, with Lewy bodies containing alpha-synuclein. This loss reduces striatal dopamine and produces the classic triad of tremor, rigidity, and bradykinesia.

Question 6Medicine

A 45-year-old woman has a deep vein thrombosis confirmed on ultrasound. She is started on a low-molecular-weight heparin. Which laboratory parameter should be monitored to assess the anticoagulant effect of this agent?

  1. International normalised ratio
  2. Anti-factor Xa activity Correct answer.
  3. Activated partial thromboplastin time
  4. Bleeding time

Explanation

Low-molecular-weight heparin predominantly inhibits factor Xa, and its effect is assessed by anti-factor Xa activity when monitoring is required, such as in renal impairment or pregnancy. Routine aPTT monitoring is not appropriate because the drug has a predictable dose response.

Question 7Medicine

A 19-year-old student develops a sore throat followed two weeks later by malaise, dark urine, and periorbital oedema. Urinalysis shows red cell casts, and complement C3 is low. Which is the most likely diagnosis?

  1. IgA nephropathy
  2. Post-streptococcal glomerulonephritis Correct answer.
  3. Acute interstitial nephritis
  4. Minimal change disease

Explanation

A nephritic syndrome developing one to three weeks after streptococcal pharyngitis, with red cell casts and low C3, is characteristic of post-streptococcal glomerulonephritis. The low complement reflects immune complex activation via the alternative pathway.

Question 8Medicine

A 60-year-old man with atrial fibrillation has a CHA2DS2-VASc score of 4. Which is the most appropriate long-term management to reduce his risk of stroke?

  1. Aspirin monotherapy
  2. Clopidogrel monotherapy
  3. Catheter ablation without anticoagulation
  4. Oral anticoagulation with a direct oral anticoagulant Correct answer.

Explanation

A CHA2DS2-VASc score of 4 confers a high annual stroke risk, and oral anticoagulation with a direct oral anticoagulant or warfarin is recommended. Antiplatelet agents are inferior for stroke prevention in non-valvular atrial fibrillation.

Question 9Medicine

A 55-year-old man with type 2 diabetes has an eGFR of 28 mL/min/1.73 m2 and an albumin-to-creatinine ratio of 350 mg/g. Which medication class slows progression of diabetic kidney disease by reducing intraglomerular pressure?

  1. Thiazolidinediones
  2. Angiotensin-converting enzyme inhibitors Correct answer.
  3. Loop diuretics
  4. Beta-blockers

Explanation

ACE inhibitors reduce angiotensin II-mediated efferent arteriolar constriction, lowering intraglomerular pressure and slowing progression of albuminuric diabetic kidney disease. They are indicated in patients with hypertension, albuminuria, and reduced eGFR.

Question 10Medicine

A 68-year-old woman has a humeral fracture after a minor fall. Dual-energy X-ray absorptiometry shows a T-score of -2.8 at the femoral neck. Which is the most appropriate first-line pharmacological treatment?

  1. Calcium and vitamin D alone
  2. Oral bisphosphonate Correct answer.
  3. Teriparatide
  4. Raloxifene

Explanation

A T-score of -2.8 with a fragility fracture confirms osteoporosis, and an oral bisphosphonate is the usual first-line therapy alongside calcium and vitamin D repletion. Bisphosphonates inhibit osteoclast-mediated bone resorption and reduce fracture risk.

Question 11Medicine

A 40-year-old man has a 6-month history of low mood, anhedonia, insomnia, and poor concentration that impairs his work. He has no suicidal ideation or psychotic features. Which is the most appropriate initial management?

  1. Antipsychotic monotherapy
  2. Long-term benzodiazepine monotherapy
  3. Selective serotonin reuptake inhibitor plus structured psychological therapy Correct answer.
  4. Electroconvulsive therapy

Explanation

Moderate depression without psychotic features or immediate risk is managed with an SSRI and/or structured psychological therapy such as cognitive behavioural therapy. Combining medication and psychotherapy is recommended for moderate to severe depression.

Question 12Medicine

A 26-year-old woman has recurrent episodes of severe abdominal pain, dark urine, and muscle weakness triggered by fasting. Urine testing shows raised porphobilinogen. Which enzyme deficiency is most likely responsible?

  1. Glucose-6-phosphate dehydrogenase
  2. Alpha-galactosidase A
  3. Porphobilinogen deaminase Correct answer.
  4. Phenylalanine hydroxylase

Explanation

Acute intermittent porphyria is caused by deficiency of porphobilinogen deaminase, leading to accumulation of porphobilinogen and delta-aminolevulinic acid. Attacks are precipitated by fasting, drugs, and hormonal changes, causing neurovisceral symptoms and dark urine.

Question 13Medicine

A 70-year-old man has a 3-month history of progressive dysphagia, initially to solids and now to liquids, with unintentional weight loss. He smokes and drinks alcohol heavily. Which investigation is the definitive diagnostic step?

  1. 24-hour pH monitoring
  2. Barium swallow
  3. Upper gastrointestinal endoscopy with biopsy Correct answer.
  4. Oesophageal manometry

Explanation

Progressive dysphagia with weight loss in a patient with smoking and alcohol risk factors raises suspicion of oesophageal carcinoma. Upper gastrointestinal endoscopy with biopsy provides histological confirmation and is the definitive diagnostic test.

Question 14Medicine

A 32-year-old woman at 34 weeks' gestation presents with a blood pressure of 158/108 mmHg and 3+ proteinuria on dipstick. She has a headache and visual disturbance. Which is the most appropriate antihypertensive agent for acute control of severe hypertension in this setting?

  1. Ramipril
  2. Atenolol
  3. Sodium nitroprusside for prolonged use
  4. Labetalol Correct answer.

Explanation

Labetalol is a first-line agent for acute severe hypertension in pre-eclampsia because it safely lowers blood pressure without compromising uteroplacental flow. Hydralazine and nifedipine are alternatives.

Question 15Medicine

A 50-year-old man presents with a swollen, painful knee. Joint aspiration yields turbid fluid with a white cell count of 60,000/mm3 and a Gram stain showing gram-positive cocci in clusters. Which is the most appropriate immediate management?

  1. Intra-articular corticosteroid injection
  2. Immobilisation alone
  3. Oral colchicine
  4. Intravenous antibiotics plus urgent joint drainage Correct answer.

Explanation

Septic arthritis requires prompt intravenous antibiotics and drainage of the joint, usually by aspiration or arthroscopy, to prevent irreversible cartilage destruction. Gram-positive cocci in clusters suggest Staphylococcus aureus, the commonest cause.

Question 16Medicine

A 22-year-old man has sudden-onset pleuritic chest pain and breathlessness. He is tall and thin, and chest examination shows reduced breath sounds and hyper-resonance on the right. Which is the most likely diagnosis?

  1. Community-acquired pneumonia
  2. Pulmonary embolism
  3. Primary spontaneous pneumothorax Correct answer.
  4. Acute pericarditis

Explanation

Sudden pleuritic pain and breathlessness with hyper-resonance and reduced breath sounds in a tall, thin young man is characteristic of primary spontaneous pneumothorax, caused by rupture of subpleural blebs. Chest radiography confirms the diagnosis.

Question 17Medicine

A 35-year-old woman has a history of recurrent pregnancy loss and a prolonged activated partial thromboplastin time that does not correct on mixing with normal plasma. Which is the most likely underlying condition?

  1. Haemophilia A
  2. Antiphospholipid syndrome Correct answer.
  3. Vitamin K deficiency
  4. Disseminated intravascular coagulation

Explanation

A prolonged aPTT that fails to correct on mixing indicates an inhibitor, and in a woman with recurrent pregnancy loss this suggests lupus anticoagulant within antiphospholipid syndrome. The condition is paradoxically prothrombotic despite prolonged clotting times in vitro.

Question 18Medicine

A 62-year-old man has progressive exertional breathlessness. Examination reveals a slow-rising carotid pulse and an ejection systolic murmur radiating to the carotids. Which is the most likely valvular lesion?

  1. Mitral regurgitation
  2. Mitral stenosis
  3. Aortic stenosis Correct answer.
  4. Aortic regurgitation

Explanation

A slow-rising pulse with an ejection systolic murmur radiating to the carotids is characteristic of aortic stenosis. The obstruction to left ventricular outflow reduces the rate of systolic pressure rise and produces a crescendo-decrescendo murmur.

Question 19Medicine

A 28-year-old man is brought in with fever, neck stiffness, and photophobia. Lumbar puncture shows a raised white cell count with neutrophil predominance, low glucose, and high protein. Which organism is the most likely cause in an unvaccinated adult?

  1. Streptococcus pneumoniae Correct answer.
  2. Neisseria meningitidis
  3. Listeria monocytogenes
  4. Cryptococcus neoformans

Explanation

Bacterial meningitis with neutrophil-predominant pleocytosis, low glucose, and high protein in an adult is most commonly caused by Streptococcus pneumoniae. Neisseria meningitidis is the next most common, but pneumococcus is the leading cause overall in adults.

Question 20Medicine

A 58-year-old man with a 40 pack-year smoking history has haemoptysis and weight loss. Chest imaging shows a central lung mass, and biopsy shows small cells with neuroendocrine features. Which paraneoplastic syndrome is most characteristically associated with this tumour?

  1. Hypercalcaemia due to parathyroid hormone-related peptide
  2. Cushing's syndrome due to ectopic ACTH from a carcinoid tumour
  3. Syndrome of inappropriate antidiuretic hormone secretion Correct answer.
  4. Hypoglycaemia due to insulinoma

Explanation

Small cell lung cancer is a neuroendocrine tumour that frequently secretes antidiuretic hormone, causing SIADH with hyponatraemia. It is also associated with ectopic ACTH, but SIADH is the most characteristic paraneoplastic endocrine manifestation.

Question 21Medicine

A 70-year-old woman presents with confusion and a urinary tract infection. She is started on an antibiotic and develops a widespread maculopapular rash, fever, and eosinophilia. Which type of hypersensitivity reaction is responsible?

  1. Type II antibody-mediated hypersensitivity
  2. Type I immediate hypersensitivity
  3. Type IV T-cell-mediated hypersensitivity Correct answer.
  4. Type III immune complex hypersensitivity

Explanation

Maculopapular drug eruptions are mediated by T lymphocytes and represent a type IV delayed hypersensitivity reaction. Eosinophilia and rash appear days after drug exposure, consistent with a cell-mediated mechanism.

Question 22Medicine

A 48-year-old man with cirrhosis presents with haematemesis. He is tachycardic and hypotensive. After resuscitation, which medication should be given to reduce portal pressure in suspected variceal bleeding?

  1. Adrenaline infusion
  2. Metoclopramide
  3. Propranolol intravenously
  4. Terlipressin Correct answer.

Explanation

Terlipressin, a vasopressin analogue, splanchnic vasoconstriction reduces portal pressure and is given early in suspected variceal bleeding alongside antibiotics and endoscopic therapy. It is the standard vasoactive agent in this acute setting.

Question 23Medicine

A 34-year-old woman has fatigue, arthralgia, and a malar rash. Investigations show a positive antinuclear antibody, anti-double-stranded DNA antibodies, and low complement. Which finding on urinalysis would most suggest renal involvement requiring urgent immunosuppression?

  1. Microscopic haematuria without proteinuria
  2. Isolated glycosuria
  3. Red cell casts with proteinuria Correct answer.
  4. Sterile pyuria alone

Explanation

Red cell casts with proteinuria indicate active glomerulonephritis, the hallmark of lupus nephritis, which requires urgent nephrology assessment and immunosuppressive therapy. Anti-dsDNA positivity and low complement correlate with disease activity.

Question 24Medicine

A 55-year-old man is admitted with confusion and a serum sodium of 112 mmol/L that developed over 48 hours. He has a history of alcohol use and is on thiazide diuretics. Which is the most appropriate initial step in management?

  1. Fluid restriction alone
  2. Immediate haemodialysis
  3. Rapid correction with hypertonic saline to a normal sodium within 6 hours
  4. Slow correction with hypertonic saline if symptomatic, aiming for a controlled rise Correct answer.

Explanation

Symptomatic severe hyponatraemia requires cautious correction with hypertonic saline, aiming for a controlled rise of about 8 to 10 mmol/L in the first 24 hours to avoid osmotic demyelination. Rapid normalisation risks serious neurological injury.

Question 25Medicine

A 60-year-old man develops sudden severe epigastric pain radiating to the back with vomiting. Serum lipase is markedly elevated. He is tachycardic and hypoxic with reduced urine output. Which finding best predicts severe acute pancreatitis according to the revised Atlanta classification?

  1. Presence of gallstones on ultrasound
  2. Persistent organ failure lasting more than 48 hours Correct answer.
  3. Serum lipase more than three times the upper limit of normal
  4. Vomiting at presentation

Explanation

Under the revised Atlanta classification, severe acute pancreatitis is defined by persistent organ failure lasting more than 48 hours, such as respiratory or renal failure. This distinguishes severe from moderately severe disease, where organ failure resolves within 48 hours.

Question 26Medicine

A 24-year-old man presents with sudden-onset right-sided chest pain and breathlessness. He is tall and thin. Chest examination reveals reduced breath sounds and hyper-resonance on the right. Which is the most likely diagnosis?

  1. Pleurisy
  2. Pneumonia
  3. Pulmonary embolism
  4. Primary spontaneous pneumothorax Correct answer.

Explanation

The classic presentation of primary spontaneous pneumothorax is sudden pleuritic chest pain and dyspnoea in a tall, thin young man, with examination findings of reduced breath sounds and hyper-resonance on the affected side. Pulmonary embolism can cause similar symptoms but typically lacks these examination findings and often has risk factors. Pneumonia and pleurisy usually present with fever and auscultatory crackles or pleural rub.

Question 27Medicine

A 58-year-old man with a 40 pack-year smoking history presents with haemoptysis and weight loss. Chest X-ray shows a central lung mass. Which histological type of lung cancer is most likely?

  1. Squamous cell carcinoma Correct answer.
  2. Small cell carcinoma
  3. Adenocarcinoma
  4. Large cell carcinoma

Explanation

Squamous cell carcinoma typically arises centrally from the major bronchi and is strongly associated with smoking. Adenocarcinoma is more often peripheral and is the most common type in non-smokers. Small cell carcinoma is also central and smoking-related but is characterised by neuroendocrine features and early metastasis.

Question 28Medicine

A 45-year-old woman has a deep vein thrombosis confirmed on ultrasound. She is started on a low-molecular-weight heparin. Which is the most appropriate immediate management?

  1. Start clopidogrel alone
  2. Continue low-molecular-weight heparin alone Correct answer.
  3. Start warfarin alone
  4. Start aspirin alone

Explanation

For acute deep vein thrombosis, low-molecular-weight heparin is the initial treatment of choice. Warfarin is not used alone initially because it can cause a transient hypercoagulable state due to protein C and S depletion. Aspirin and clopidogrel are antiplatelet agents and are not effective for venous thromboembolism.

Question 29Medicine

A 62-year-old man has progressive exertional breathlessness. Examination reveals a slow-rising carotid pulse and an ejection systolic murmur radiating to the carotids. Which is the most likely diagnosis?

  1. Mitral regurgitation
  2. Mitral stenosis
  3. Aortic regurgitation
  4. Aortic stenosis Correct answer.

Explanation

Aortic stenosis classically presents with exertional dyspnoea, angina, or syncope, and examination findings of a slow-rising (pulsus parvus et tardus) carotid pulse and an ejection systolic murmur radiating to the carotids. Mitral regurgitation causes a pansystolic murmur radiating to the axilla. Aortic regurgitation causes a collapsing pulse and an early diastolic murmur. Mitral stenosis causes a mid-diastolic murmur with a loud first heart sound.

Question 30Medicine

A 70-year-old woman presents with confusion and a urinary tract infection. She is started on an antibiotic and develops Clostridioides difficile infection. Which is the most appropriate treatment?

  1. Oral ciprofloxacin
  2. Oral vancomycin Correct answer.
  3. Oral metronidazole
  4. Intravenous vancomycin

Explanation

Oral vancomycin is the first-line treatment for Clostridioides difficile infection, especially for severe cases. Intravenous vancomycin is not effective because it does not reach the colon lumen. Oral metronidazole is an alternative for mild cases but is less effective than oral vancomycin. Ciprofloxacin can precipitate C. difficile infection and is not a treatment.

Question 31Medicine

A 48-year-old man with cirrhosis presents with haematemesis. He is tachycardic and hypotensive. After resuscitation, which is the most appropriate initial management?

  1. Intravenous vitamin K
  2. Oral omeprazole
  3. Intravenous propranolol
  4. Intravenous terlipressin Correct answer.

Explanation

In acute variceal bleeding, terlipressin is used to reduce portal pressure and control bleeding. Propranolol is used for prophylaxis, not acute bleeding. Omeprazole is not effective for variceal bleeding. Vitamin K is used for coagulopathy but is not the primary treatment for variceal haemorrhage.

Question 32Medicine

A 34-year-old woman has fatigue, arthralgia, and a malar rash. Investigations show a positive antinuclear antibody, anti-double-stranded DNA, and low complement levels. Which is the most likely diagnosis?

  1. Dermatomyositis
  2. Systemic lupus erythematosus Correct answer.
  3. Systemic sclerosis
  4. Rheumatoid arthritis

Explanation

The combination of a malar rash, arthralgia, positive ANA, anti-dsDNA, and low complement is highly specific for systemic lupus erythematosus. Rheumatoid arthritis typically presents with symmetrical small joint arthritis and positive anti-CCP or rheumatoid factor. Systemic sclerosis is characterised by skin thickening and anti-topoisomerase or anti-centromere antibodies. Dermatomyositis presents with proximal muscle weakness and a heliotrope rash.

Question 33Medicine

A 55-year-old man is admitted with confusion and a serum sodium of 112 mmol/L that developed over 48 hours. He has a history of excessive water intake. Which is the most appropriate initial management?

  1. Fluid restriction
  2. Demeclocycline
  3. Intravenous furosemide
  4. Hypertonic saline Correct answer.

Explanation

Severe symptomatic hyponatraemia (serum sodium <120 mmol/L) with confusion requires urgent correction with hypertonic (3%) saline to prevent cerebral oedema and neurological damage. Fluid restriction is used for mild asymptomatic hyponatraemia or SIADH. Furosemide and demeclocycline are not first-line for acute severe hyponatraemia.

Question 34Medicine

A 60-year-old man develops sudden severe epigastric pain radiating to the back with vomiting. Serum lipase is markedly elevated. Which is the most likely cause?

  1. Acute pancreatitis Correct answer.
  2. Acute cholecystitis
  3. Perforated peptic ulcer
  4. Myocardial infarction

Explanation

Acute pancreatitis typically presents with severe epigastric pain radiating to the back, vomiting, and markedly elevated serum lipase or amylase. Acute cholecystitis causes right upper quadrant pain and fever. Perforated peptic ulcer causes sudden severe pain with rigidity. Myocardial infarction can cause epigastric pain but lipase is not elevated.

Question 35Medicine

A 32-year-old woman at 34 weeks' gestation presents with a blood pressure of 158/108 mmHg and 3+ proteinuria on dipstick. Which is the most appropriate management?

  1. Delivery Correct answer.
  2. Corticosteroids
  3. Expectant management with antihypertensives
  4. Magnesium sulfate

Explanation

Severe pre-eclampsia at 34 weeks' gestation is an indication for delivery to prevent maternal and fetal complications. Expectant management may be considered in milder cases but not with severe features. Magnesium sulfate is used for seizure prophylaxis, not as the primary treatment. Corticosteroids are given for fetal lung maturity if delivery is anticipated before 34 weeks.

Question 36Medicine

A 50-year-old man presents with a swollen, painful knee. Joint aspiration yields turbid fluid with a white cell count of 50,000/mm³ and Gram-positive cocci in clusters. Which is the most likely organism?

  1. Staphylococcus aureus Correct answer.
  2. Escherichia coli
  3. Neisseria gonorrhoeae
  4. Streptococcus pyogenes

Explanation

Septic arthritis in adults is most commonly caused by Staphylococcus aureus, which appears as Gram-positive cocci in clusters. Neisseria gonorrhoeae is a Gram-negative diplococcus and is more common in sexually active young adults. Streptococcus pyogenes is Gram-positive cocci in chains. Escherichia coli is Gram-negative and more common in immunocompromised or elderly patients.

Question 37Medicine

A 26-year-old woman has recurrent episodes of severe abdominal pain, dark urine, and muscle weakness triggered by fasting. Which is the most likely diagnosis?

  1. Alpha-1 antitrypsin deficiency
  2. Acute intermittent porphyria Correct answer.
  3. Wilson disease
  4. Hereditary haemochromatosis

Explanation

Acute intermittent porphyria presents with neurovisceral symptoms such as abdominal pain, dark urine, and muscle weakness, often triggered by fasting, infections, or medications. Hereditary haemochromatosis causes fatigue, arthralgia, and bronze diabetes. Wilson disease presents with liver disease and neuropsychiatric symptoms. Alpha-1 antitrypsin deficiency causes early-onset emphysema and liver disease.

Question 38Medicine

A 70-year-old man has a 3-month history of progressive dysphagia, initially to solids and now to liquids, with unintentional weight loss. Which is the most likely diagnosis?

  1. Gastro-oesophageal reflux disease
  2. Achalasia
  3. Oesophageal cancer Correct answer.
  4. Oesophageal stricture

Explanation

Progressive dysphagia from solids to liquids, accompanied by weight loss, is a red flag for oesophageal cancer. Achalasia typically causes intermittent dysphagia to both solids and liquids. Gastro-oesophageal reflux disease usually causes heartburn and regurgitation, not progressive dysphagia. Oesophageal stricture causes dysphagia but is usually preceded by longstanding reflux or caustic injury.

Question 39Medicine

A 28-year-old man is brought in with fever, neck stiffness, and photophobia. Lumbar puncture shows a raised white cell count with neutrophil predominance, low glucose, and high protein. Which is the most likely causative organism?

  1. Streptococcus pneumoniae Correct answer.
  2. Listeria monocytogenes
  3. Herpes simplex virus
  4. Neisseria meningitidis

Explanation

Bacterial meningitis in adults is most commonly caused by Streptococcus pneumoniae, which presents with neutrophilic pleocytosis, low glucose, and high protein. Neisseria meningitidis is also common but often occurs in outbreaks or younger patients. Listeria monocytogenes is more common in immunocompromised or elderly patients. Herpes simplex virus causes viral meningitis with lymphocytic pleocytosis and normal glucose.

Question 40Medicine

A 19-year-old student develops a sore throat followed two weeks later by malaise, dark urine, and periorbital oedema. Urinalysis shows haematuria and proteinuria. Which is the most likely diagnosis?

  1. IgA nephropathy
  2. Membranous nephropathy
  3. Minimal change disease
  4. Post-streptococcal glomerulonephritis Correct answer.

Explanation

Post-streptococcal glomerulonephritis typically occurs 1–2 weeks after a streptococcal throat or skin infection and presents with haematuria, proteinuria, oedema, and hypertension. IgA nephropathy causes recurrent haematuria coinciding with respiratory infections, not a latent period. Minimal change disease presents with nephrotic syndrome without haematuria. Membranous nephropathy causes nephrotic syndrome in older adults.

Question 41Medicine

A 60-year-old man with atrial fibrillation has a CHA2DS2-VASc score of 4. Which is the most appropriate long-term management?

  1. Aspirin
  2. Oral anticoagulation Correct answer.
  3. No antithrombotic therapy
  4. Clopidogrel

Explanation

A CHA2DS2-VASc score of 4 indicates a high risk of stroke, and oral anticoagulation is recommended for stroke prevention in atrial fibrillation. Aspirin and clopidogrel are antiplatelet agents and are less effective than anticoagulation. No antithrombotic therapy is inappropriate given the high stroke risk.

Question 42Medicine

A 55-year-old man with type 2 diabetes has an eGFR of 28 mL/min/1.73 m² and an albumin-to-creatinine ratio of 350 mg/g. Which is the most appropriate management?

  1. Metformin
  2. Sulfonylurea
  3. Insulin
  4. SGLT2 inhibitor Correct answer.

Explanation

SGLT2 inhibitors are recommended for patients with type 2 diabetes and chronic kidney disease (eGFR ≥20 mL/min/1.73 m²) to slow progression of kidney disease and reduce cardiovascular risk. Metformin is contraindicated when eGFR <30 mL/min/1.73 m² due to the risk of lactic acidosis. Sulfonylureas and insulin are not first-line for renoprotection.

Question 43Medicine

A 68-year-old woman has a humeral fracture after a minor fall. Dual-energy X-ray absorptiometry shows a T-score of -2.8 at the femoral neck. Which is the most appropriate treatment?

  1. Raloxifene
  2. Bisphosphonate Correct answer.
  3. Calcium and vitamin D alone
  4. Hormone replacement therapy

Explanation

A T-score ≤ -2.5 indicates osteoporosis, and bisphosphonates are first-line treatment to reduce fracture risk. Calcium and vitamin D alone are insufficient for treating osteoporosis. Hormone replacement therapy and raloxifene are alternatives but not first-line for postmenopausal osteoporosis with a high fracture risk.

Question 44Medicine

A 40-year-old man has a 6-month history of low mood, anhedonia, insomnia, and poor concentration that impairs his work. Which is the most appropriate initial treatment?

  1. Electroconvulsive therapy
  2. Antipsychotic
  3. Cognitive behavioural therapy Correct answer.
  4. Lithium

Explanation

For moderate to severe depression, cognitive behavioural therapy or a selective serotonin reuptake inhibitor is first-line. Electroconvulsive therapy is reserved for severe or treatment-resistant depression. Lithium is used for bipolar disorder. Antipsychotics are not first-line for depression unless there are psychotic features.

Question 45Medicine

A 35-year-old woman has a history of recurrent pregnancy loss and a prolonged activated partial thromboplastin time that does not correct with mixing. Which is the most likely diagnosis?

  1. Haemophilia A
  2. Antiphospholipid syndrome Correct answer.
  3. Von Willebrand disease
  4. Factor VII deficiency

Explanation

Antiphospholipid syndrome is characterised by recurrent pregnancy loss, thrombosis, and a prolonged aPTT that does not correct with mixing due to the presence of an inhibitor (lupus anticoagulant). Haemophilia A and von Willebrand disease correct with mixing. Factor VII deficiency prolongs the prothrombin time, not the aPTT.

Question 46Medicine

A 22-year-old man has sudden-onset pleuritic chest pain and breathlessness. He is tall and thin, and chest examination shows reduced breath sounds and hyper-resonance on the right. Which is the most appropriate initial investigation?

  1. Chest X-ray Correct answer.
  2. D-dimer
  3. ECG
  4. CT pulmonary angiogram

Explanation

Chest X-ray is the initial investigation for suspected pneumothorax, confirming the diagnosis and assessing its size. CT pulmonary angiogram is used for suspected pulmonary embolism. D-dimer is used to rule out pulmonary embolism in low-risk patients. ECG is not diagnostic for pneumothorax.

Question 47Medicine

A 58-year-old man with a 40 pack-year smoking history has haemoptysis and weight loss. Chest imaging shows a central lung mass. Which is the most appropriate next step in management?

  1. CT-guided biopsy
  2. PET-CT
  3. Bronchoscopy with biopsy Correct answer.
  4. Sputum cytology

Explanation

For a central lung mass, bronchoscopy with biopsy is the preferred initial procedure to obtain a tissue diagnosis. CT-guided biopsy is more suitable for peripheral lesions. Sputum cytology has low sensitivity. PET-CT is used for staging, not as the primary diagnostic procedure.

Question 48Medicine

A 70-year-old woman presents with confusion and a urinary tract infection. She is started on an antibiotic and develops Clostridioides difficile infection. Which is the most appropriate initial step in management?

  1. Stop the offending antibiotic Correct answer.
  2. Start intravenous metronidazole
  3. Start oral vancomycin
  4. Start loperamide

Explanation

The first step in managing Clostridioides difficile infection is to stop the offending antibiotic if possible, as this alone can resolve mild cases. Loperamide is contraindicated as it can precipitate toxic megacolon. Oral vancomycin is used for severe cases but stopping the antibiotic is the initial step. Intravenous metronidazole is not effective for C. difficile.

Question 49Medicine

A 48-year-old man with cirrhosis presents with haematemesis. He is tachycardic and hypotensive. After resuscitation, which is the most appropriate initial pharmacological treatment?

  1. Terlipressin Correct answer.
  2. Omeprazole
  3. Propranolol
  4. Vitamin K

Explanation

Terlipressin is a vasoactive drug used to reduce portal pressure in acute variceal bleeding. Propranolol is used for prophylaxis, not acute bleeding. Omeprazole is not effective for variceal bleeding. Vitamin K is used for coagulopathy but is not the primary treatment for variceal haemorrhage.

Question 50Medicine

A 34-year-old woman has fatigue, arthralgia, and a malar rash. Investigations show a positive antinuclear antibody, anti-double-stranded DNA, and low complement levels. Which is the most appropriate initial treatment?

  1. Cyclophosphamide
  2. High-dose corticosteroids
  3. Rituximab
  4. Hydroxychloroquine Correct answer.

Explanation

Hydroxychloroquine is the cornerstone of treatment for systemic lupus erythematosus, reducing flares and improving long-term outcomes. High-dose corticosteroids are used for severe flares but are not first-line for mild disease. Cyclophosphamide and rituximab are reserved for severe organ-threatening disease.