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COMSAE COMBINED PHASES PROFESSIONAL EXAM – FORM 115 Questions
with Detailed Rationales UPDATED
Updated 2026/2027 Edition
Total Questions: 176
Sections: 4 × 44 Questions
Time Allowed: 4 hours
SECTION 1 (Questions 1–44)
Question 1
A 55-year-old man with a 40-pack-year smoking history
presents with a painless, pearly papule with telangiectasias on
his nose. What is the most likely diagnosis?
A. Squamous cell carcinoma
B. Basal cell carcinoma
C. Melanoma
D. Actinic keratosis
E. Seborrheic keratosis
Answer: B
Rationale: Basal cell carcinoma typically presents as a pearly
papule with telangiectasias on sun-exposed skin. Squamous cell
carcinoma is often a scaly, erythematous plaque; melanoma is
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pigmented and asymmetric; actinic keratosis is a rough, scaly
patch.
Question 2
Which of the following is the rate-limiting enzyme of glycolysis?
A. Hexokinase
B. Phosphofructokinase-1
C. Pyruvate kinase
D. Aldolase
E. Glyceraldehyde-3-phosphate dehydrogenase
Answer: B
Rationale: Phosphofructokinase-1 (PFK-1) is the committed,
rate-limiting step of glycolysis and is allosterically regulated by
ATP, AMP, and citrate.
Question 3
A 62-year-old woman with type 2 diabetes and hypertension
presents with fatigue and dyspnea. Labs: hemoglobin 9.2 g/dL,
MCV 85 fL, ferritin 200 ng/mL, transferrin saturation 15%. What
is the most likely cause of anemia?
A. Iron deficiency anemia
B. Anemia of chronic disease
C. Vitamin B12 deficiency
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D. Hemolytic anemia
E. Aplastic anemia
Answer: B
Rationale: Anemia of chronic disease is normocytic or mildly
microcytic with normal/high ferritin and low transferrin
saturation. It is common in CKD, diabetes, and chronic
inflammation. Iron deficiency would show low ferritin; B12
deficiency would be macrocytic.
Question 4
A 70-year-old man presents with sudden onset of severe
headache and nuchal rigidity. CT head is negative. Lumbar
puncture shows xanthochromia. What is the most likely
diagnosis?
A. Migraine
B. Subarachnoid hemorrhage
C. Bacterial meningitis
D. Cluster headache
E. Tension headache
Answer: B
Rationale: Xanthochromia (bilirubin from RBC breakdown) in
CSF after a negative CT indicates subarachnoid hemorrhage. CT
can miss small SAH; LP is essential if suspicion remains.
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Question 5
Which of the following is the primary inhibitory
neurotransmitter in the brain?
A. Glutamate
B. GABA
C. Glycine
D. Dopamine
E. Acetylcholine
Answer: B
Rationale: GABA is the major inhibitory neurotransmitter in the
central nervous system. Glycine is predominant in the spinal
cord and brainstem.
Question 6
A 45-year-old woman presents with right upper quadrant pain
after fatty meals, fever, and a positive Murphy's sign. WBC
13,000/µL. What is the most likely diagnosis?
A. Acute cholecystitis
B. Acute pancreatitis
C. Peptic ulcer disease
D. Hepatitis
E. Appendicitis
COMSAE COMBINED PHASES PROFESSIONAL EXAM – FORM 115 Questions
with Detailed Rationales UPDATED
Updated 2026/2027 Edition
Total Questions: 176
Sections: 4 × 44 Questions
Time Allowed: 4 hours
SECTION 1 (Questions 1–44)
Question 1
A 55-year-old man with a 40-pack-year smoking history
presents with a painless, pearly papule with telangiectasias on
his nose. What is the most likely diagnosis?
A. Squamous cell carcinoma
B. Basal cell carcinoma
C. Melanoma
D. Actinic keratosis
E. Seborrheic keratosis
Answer: B
Rationale: Basal cell carcinoma typically presents as a pearly
papule with telangiectasias on sun-exposed skin. Squamous cell
carcinoma is often a scaly, erythematous plaque; melanoma is
, Page |2
pigmented and asymmetric; actinic keratosis is a rough, scaly
patch.
Question 2
Which of the following is the rate-limiting enzyme of glycolysis?
A. Hexokinase
B. Phosphofructokinase-1
C. Pyruvate kinase
D. Aldolase
E. Glyceraldehyde-3-phosphate dehydrogenase
Answer: B
Rationale: Phosphofructokinase-1 (PFK-1) is the committed,
rate-limiting step of glycolysis and is allosterically regulated by
ATP, AMP, and citrate.
Question 3
A 62-year-old woman with type 2 diabetes and hypertension
presents with fatigue and dyspnea. Labs: hemoglobin 9.2 g/dL,
MCV 85 fL, ferritin 200 ng/mL, transferrin saturation 15%. What
is the most likely cause of anemia?
A. Iron deficiency anemia
B. Anemia of chronic disease
C. Vitamin B12 deficiency
, Page |3
D. Hemolytic anemia
E. Aplastic anemia
Answer: B
Rationale: Anemia of chronic disease is normocytic or mildly
microcytic with normal/high ferritin and low transferrin
saturation. It is common in CKD, diabetes, and chronic
inflammation. Iron deficiency would show low ferritin; B12
deficiency would be macrocytic.
Question 4
A 70-year-old man presents with sudden onset of severe
headache and nuchal rigidity. CT head is negative. Lumbar
puncture shows xanthochromia. What is the most likely
diagnosis?
A. Migraine
B. Subarachnoid hemorrhage
C. Bacterial meningitis
D. Cluster headache
E. Tension headache
Answer: B
Rationale: Xanthochromia (bilirubin from RBC breakdown) in
CSF after a negative CT indicates subarachnoid hemorrhage. CT
can miss small SAH; LP is essential if suspicion remains.
, Page |4
Question 5
Which of the following is the primary inhibitory
neurotransmitter in the brain?
A. Glutamate
B. GABA
C. Glycine
D. Dopamine
E. Acetylcholine
Answer: B
Rationale: GABA is the major inhibitory neurotransmitter in the
central nervous system. Glycine is predominant in the spinal
cord and brainstem.
Question 6
A 45-year-old woman presents with right upper quadrant pain
after fatty meals, fever, and a positive Murphy's sign. WBC
13,000/µL. What is the most likely diagnosis?
A. Acute cholecystitis
B. Acute pancreatitis
C. Peptic ulcer disease
D. Hepatitis
E. Appendicitis
