2026 EDITION COMSAE Phase 10Exam
Questions with Correct Answers and
Concise Rationales
1. A 24-year-old woman presents with fatigue, weight loss,
heat intolerance, and palpitations. Examination reveals a
diffuse, nontender goiter and bilateral exophthalmos.
Laboratory studies show elevated free T4 and suppressed
TSH. Which mechanism best explains her condition?
A. Destruction of thyroid follicles by cytotoxic T cells
B. Antibodies stimulating the TSH receptor
C. Autonomous thyroid hormone production from a toxic
adenoma
D. Excessive hypothalamic TRH secretion
Answer: B. Antibodies stimulating the TSH receptor
Rationale: Graves disease results from thyroid-stimulating
immunoglobulins that activate the TSH receptor, causing
diffuse thyroid enlargement and excessive hormone
production.
2. A 67-year-old man develops sudden right-sided weakness
and expressive aphasia. Imaging reveals an infarct involving
the dominant inferior frontal gyrus. Which artery is most
likely occluded?
,A. Anterior cerebral artery
B. Posterior cerebral artery
C. Superior division of the middle cerebral artery
D. Inferior division of the middle cerebral artery
Answer: C. Superior division of the middle cerebral artery
Rationale: The dominant inferior frontal gyrus contains Broca
area, supplied primarily by the superior division of the middle
cerebral artery.
3. A patient with chronic hypertension develops progressive
renal insufficiency. Renal biopsy shows concentric thickening
of arteriolar walls with an “onion-skin” appearance. Which
process is responsible?
A. Hyaline arteriolosclerosis
B. Hyperplastic arteriolosclerosis
C. Fibrinoid necrosis
D. Atherosclerosis
Answer: B. Hyperplastic arteriolosclerosis
Rationale: Severe hypertension produces hyperplastic
arteriolosclerosis, characterized by concentric smooth-muscle
proliferation and basement membrane duplication.
4. A 32-year-old woman presents with recurrent episodes of
painful swelling of her knees and ankles. Synovial fluid
demonstrates needle-shaped, negatively birefringent crystals.
Which substance is elevated?
,A. Calcium pyrophosphate
B. Calcium hydroxyapatite
C. Monosodium urate
D. Cholesterol
Answer: C. Monosodium urate
Rationale: Gout is caused by deposition of monosodium urate
crystals, which appear needle-shaped and negatively
birefringent under polarized light.
5. A 19-year-old college student presents with fever,
headache, neck stiffness, and a petechial rash. Cerebrospinal
fluid shows neutrophilic pleocytosis and low glucose. Which
organism is most likely responsible?
A. Listeria monocytogenes
B. Neisseria meningitidis
C. Cryptococcus neoformans
D. Herpes simplex virus
Answer: B. Neisseria meningitidis
Rationale: Meningococcal meningitis commonly affects
adolescents and young adults and may produce a petechial or
purpuric rash due to endotoxin-mediated sepsis.
6. A 45-year-old man develops severe epigastric pain
radiating to the back after heavy alcohol use. Serum lipase is
markedly elevated. Which complication is most characteristic
of acute pancreatitis?
, A. Hypercalcemia
B. Hypoglycemia
C. Fat necrosis
D. Increased bicarbonate secretion
Answer: C. Fat necrosis
Rationale: Pancreatic lipase causes enzymatic fat necrosis,
releasing fatty acids that bind calcium and may produce
hypocalcemia.
7. A patient with Parkinson disease is started on a medication
that inhibits peripheral conversion of levodopa to dopamine.
Which drug was prescribed?
A. Selegiline
B. Entacapone
C. Benztropine
D. Amantadine
Answer: B. Entacapone
Rationale: Entacapone inhibits catechol-O-methyltransferase,
prolonging levodopa availability and reducing peripheral
metabolism.
8. A 58-year-old man presents with painless hematuria. He
has a 40-pack-year smoking history. Cystoscopy reveals a
papillary bladder mass. Which tumor is most likely?
A. Squamous cell carcinoma
B. Adenocarcinoma
Questions with Correct Answers and
Concise Rationales
1. A 24-year-old woman presents with fatigue, weight loss,
heat intolerance, and palpitations. Examination reveals a
diffuse, nontender goiter and bilateral exophthalmos.
Laboratory studies show elevated free T4 and suppressed
TSH. Which mechanism best explains her condition?
A. Destruction of thyroid follicles by cytotoxic T cells
B. Antibodies stimulating the TSH receptor
C. Autonomous thyroid hormone production from a toxic
adenoma
D. Excessive hypothalamic TRH secretion
Answer: B. Antibodies stimulating the TSH receptor
Rationale: Graves disease results from thyroid-stimulating
immunoglobulins that activate the TSH receptor, causing
diffuse thyroid enlargement and excessive hormone
production.
2. A 67-year-old man develops sudden right-sided weakness
and expressive aphasia. Imaging reveals an infarct involving
the dominant inferior frontal gyrus. Which artery is most
likely occluded?
,A. Anterior cerebral artery
B. Posterior cerebral artery
C. Superior division of the middle cerebral artery
D. Inferior division of the middle cerebral artery
Answer: C. Superior division of the middle cerebral artery
Rationale: The dominant inferior frontal gyrus contains Broca
area, supplied primarily by the superior division of the middle
cerebral artery.
3. A patient with chronic hypertension develops progressive
renal insufficiency. Renal biopsy shows concentric thickening
of arteriolar walls with an “onion-skin” appearance. Which
process is responsible?
A. Hyaline arteriolosclerosis
B. Hyperplastic arteriolosclerosis
C. Fibrinoid necrosis
D. Atherosclerosis
Answer: B. Hyperplastic arteriolosclerosis
Rationale: Severe hypertension produces hyperplastic
arteriolosclerosis, characterized by concentric smooth-muscle
proliferation and basement membrane duplication.
4. A 32-year-old woman presents with recurrent episodes of
painful swelling of her knees and ankles. Synovial fluid
demonstrates needle-shaped, negatively birefringent crystals.
Which substance is elevated?
,A. Calcium pyrophosphate
B. Calcium hydroxyapatite
C. Monosodium urate
D. Cholesterol
Answer: C. Monosodium urate
Rationale: Gout is caused by deposition of monosodium urate
crystals, which appear needle-shaped and negatively
birefringent under polarized light.
5. A 19-year-old college student presents with fever,
headache, neck stiffness, and a petechial rash. Cerebrospinal
fluid shows neutrophilic pleocytosis and low glucose. Which
organism is most likely responsible?
A. Listeria monocytogenes
B. Neisseria meningitidis
C. Cryptococcus neoformans
D. Herpes simplex virus
Answer: B. Neisseria meningitidis
Rationale: Meningococcal meningitis commonly affects
adolescents and young adults and may produce a petechial or
purpuric rash due to endotoxin-mediated sepsis.
6. A 45-year-old man develops severe epigastric pain
radiating to the back after heavy alcohol use. Serum lipase is
markedly elevated. Which complication is most characteristic
of acute pancreatitis?
, A. Hypercalcemia
B. Hypoglycemia
C. Fat necrosis
D. Increased bicarbonate secretion
Answer: C. Fat necrosis
Rationale: Pancreatic lipase causes enzymatic fat necrosis,
releasing fatty acids that bind calcium and may produce
hypocalcemia.
7. A patient with Parkinson disease is started on a medication
that inhibits peripheral conversion of levodopa to dopamine.
Which drug was prescribed?
A. Selegiline
B. Entacapone
C. Benztropine
D. Amantadine
Answer: B. Entacapone
Rationale: Entacapone inhibits catechol-O-methyltransferase,
prolonging levodopa availability and reducing peripheral
metabolism.
8. A 58-year-old man presents with painless hematuria. He
has a 40-pack-year smoking history. Cystoscopy reveals a
papillary bladder mass. Which tumor is most likely?
A. Squamous cell carcinoma
B. Adenocarcinoma
