70 clinical MCQs in Uncategorized. Which tumor marker is most specific for hepatocellular carcinoma? —. Kenya, Africa and global revision.
Q1. Which tumor marker is most specific for hepatocellular carcinoma? ---
Answer: AFP
Q2. A patient with small cell lung cancer develops hyponatremia with concentrated urine. The ectopic hormone responsible is ---
Answer: ADH
Q3. CA 125 is the tumor marker of choice for monitoring treatment response in ---
Answer: Ovarian cancer
Q4. Which lab finding best distinguishes ectopic ACTH syndrome from pituitary Cushing disease? ---
Answer: Very high ACTH with failed high-dose dexamethasone suppression
Q5. A man with bronchogenic carcinoma has calcium 13.2 mg/dL with suppressed PTH. The mediator is ---
Answer: PTHrP
Q6. The most common cause of delayed puberty in boys is ---
Answer: Constitutional delay of growth and puberty
Q7. A 16-year-old girl has no breast development, primary amenorrhea, and elevated FSH/LH. Karyotype is 45,X. Diagnosis ---
Answer: Turner syndrome
Q8. Precocious puberty in girls is defined as secondary sexual development before age ---
Answer: 8 years
Q9. A 6-year-old boy has pubic hair, enlarged testes, and pubertal LH response to GnRH. Diagnosis ---
Answer: Central precocious puberty
Q10. The most common cause of hirsutism in reproductive-age women is ---
Answer: Polycystic ovary syndrome
Q11. Best biochemical marker of adrenal androgen excess in hirsutism ---
Answer: DHEA-S
Q12. Which feature is NOT part of virilism in women? ---
Answer: Galactorrhea
Q13. Semen analysis: count 10 million/mL, motility 20%, morphology 2%. This is ---
Answer: Oligoasthenoteratozoospermia
Q14. WHO lower reference limit for normal sperm concentration is ---
Answer: 15 million/mL
Q15. Elevated FSH with azoospermia in a male infertility workup suggests ---
Answer: Primary testicular failure
Q16. Aminoglycoside trough level sample should be collected ---
Answer: Just before the next dose
Q17. Which drug has the narrowest therapeutic index requiring routine TDM? ---
Answer: Digoxin
Q18. In acetaminophen toxicity, the antidote N-acetylcysteine works by replenishing ---
Answer: Glutathione
Q19. Carbon monoxide poisoning is confirmed by measuring ---
Answer: Carboxyhemoglobin
Q20. In salicylate toxicity, the earliest acid-base disturbance is ---
Answer: Respiratory alkalosis
Q21. Phenylketonuria results from deficiency of ---
Answer: Phenylalanine hydroxylase
Q22. The newborn screening test for PKU measures ---
Answer: Serum phenylalanine
Q23. A patient with dark urine on standing, ochronosis, and arthritis has ---
Answer: Alkaptonuria
Q24. Maple syrup urine disease involves accumulation of ---
Answer: Branched-chain amino acids
Q25. Classic galactosemia is due to deficiency of ---
Answer: Galactose-1-phosphate uridyltransferase
Q26. The gold standard for diagnosing osteoporosis is ---
Answer: DEXA scan
Q27. In Paget's disease of bone, which marker is most characteristically elevated? ---
Answer: Alkaline phosphatase
Q28. Primary hyperparathyroidism characteristically shows ---
Answer: High calcium, low phosphate, high PTH
Q29. The enzyme deficient in classic gout leading to hyperuricemia is ---
Answer: Hypoxanthine-guanine phosphoribosyltransferase (HGPRT)
Q30. Allopurinol treats gout by inhibiting ---
Answer: Xanthine oxidase
Q31. The hypothalamic hormone that stimulates both FSH and LH release is ---
Answer: GnRH
Q32. Growth hormone excess before epiphyseal fusion causes ---
Answer: Gigantism
Q33. The best screening test for acromegaly is ---
Answer: IGF-1
Q34. Diabetes insipidus is characterized by ---
Answer: Low urine osmolality, high serum osmolality
Q35. A patient has low TSH and high free T4. The most likely diagnosis is ---
Answer: Primary hyperthyroidism
Q36. The best initial test to evaluate thyroid function is ---
Answer: TSH
Q37. Hashimoto's thyroiditis is associated with antibodies against ---
Answer: Thyroglobulin and thyroid peroxidase
Q38. The HbA1c reflects average blood glucose over the preceding ---
Answer: 4 months
Q39. Diagnostic criterion for diabetes mellitus using fasting plasma glucose is ---
Answer: ≥ 7.0 mmol/L
Q40. In diabetic ketoacidosis, the predominant ketone body measured by nitroprusside test is ---
Answer: Acetoacetate
Q41. C-peptide measurement helps differentiate type 1 DM from factitious hypoglycemia because ---
Answer: Exogenous insulin suppresses C-peptide
Q42. The classic triad of Cushing syndrome includes all EXCEPT ---
Answer: Hypoglycemia
Q43. The best outpatient screening test for Cushing syndrome is ---
Answer: Overnight 1 mg dexamethasone suppression test
Q44. Primary hyperaldosteronism (Conn syndrome) characteristically presents with ---
Answer: Hypokalemia, hypertension, low renin
Q45. In congenital adrenal hyperplasia due to 21-hydroxylase deficiency, which metabolite is elevated? ---
Answer: 17-hydroxyprogesterone
Q46. The earliest marker of glomerular damage in diabetic nephropathy is ---
Answer: Microalbuminuria
Q47. Which formula is used to estimate GFR in clinical practice? ---
Answer: Cockcroft-Gault or CKD-EPI
Q48. In nephrotic syndrome, the urine dipstick finding is ---
Answer: 4+ proteinuria
Q49. The most sensitive early indicator of tubular dysfunction is ---
Answer: Urine beta-2 microglobulin
Q50. In pre-renal acute kidney injury, urine sodium is typically ---
Answer: < 20 mmol/L
Q51. The BUN/creatinine ratio in pre-renal AKI is typically ---
Answer: > 20:1
Q52. Calcium oxalate crystals in urine are associated with which type of renal calculi? ---
Answer: Calcium oxalate stones
Q53. Struvite (triple phosphate) renal stones are associated with ---
Answer: Urease-producing bacterial infections
Q54. In chronic kidney disease, which electrolyte abnormality is most life-threatening? ---
Answer: Hyperkalemia
Q55. The enzyme deficient in acute intermittent porphyria (AIP) is ---
Answer: Porphobilinogen deaminase
Q56. The most reliable urine marker during an acute attack of AIP is ---
Answer: Porphobilinogen
Q57. Porphyria cutanea tarda presents with ---
Answer: Photosensitive skin blistering
Q58. Which porphyria is associated with deficiency of ferrochelatase and presents with photosensitivity? ---
Answer: Erythropoietic protoporphyria
Q59. The rate-limiting enzyme of heme synthesis is ---
Answer: ALA synthase
Q60. Prolactinoma causes infertility in women primarily by ---
Answer: Inhibiting GnRH pulsatility
Q61. Which pituitary hormone deficiency occurs last in progressive hypopituitarism? ---
Answer: TSH
Q62. A patient with lithium therapy develops polyuria and polydipsia. The most likely mechanism is ---
Answer: Nephrogenic DI from ADH resistance
Q63. The syndrome of inappropriate ADH secretion (SIADH) is characterized by ---
Answer: Hyponatremia with inappropriately concentrated urine
Q64. In Addison's disease, the expected electrolyte pattern is ---
Answer: Hyponatremia, hyperkalemia, hypoglycemia
Q65. The confirmatory test for primary adrenal insufficiency is ---
Answer: Short Synacthen (ACTH stimulation) test
Q66. Calcitonin is used as a tumor marker for ---
Answer: Medullary thyroid cancer
Q67. A patient has low serum calcium, high phosphate, and elevated PTH. The most likely diagnosis is ---
Answer: Secondary hyperparathyroidism
Q68. The oral glucose tolerance test (OGTT) uses a glucose load of ---
Answer: 75 g
Q69. Homocystinuria is associated with deficiency of ---
Answer: Cystathionine beta-synthase
Q70. In von Gierke disease (GSD type I), the deficient enzyme causes fasting hypoglycemia due to inability to perform
Answer: Glycogenolysis and gluconeogenesis via glucose-6-phosphatase deficiency