Medical Council of Canada Qualifying
Examination Part I MCCQE1 EXAM 2026
**1. A 45-year-old man presents with crushing chest pain radiating to his left arm.
ECG shows ST elevation in leads V1-V4. Which artery is most likely occluded?**
A) Right coronary artery
B) Left circumflex artery
C) Left anterior descending artery (correct answer)
D) Posterior descending artery
**Rationale:** ST elevation in V1-V4 indicates anteroseptal MI, typically caused
by LAD occlusion.
**2. A 28-year-old woman presents with fatigue, pallor, and pica (eating ice). CBC
shows microcytic hypochromic anemia. What is the most likely diagnosis?**
A) Vitamin B12 deficiency
B) Iron deficiency anemia (correct answer)
C) Thalassemia
D) Sickle cell anemia
,**Rationale:** Microcytic hypochromic anemia with pica is classic for iron
deficiency.
**3. A 65-year-old man with COPD presents with worsening dyspnea, increased
sputum production, and fever. Arterial blood gas shows pH 7.30, PaCO2 65 mmHg,
PaO2 55 mmHg. What is the primary acid-base disturbance?**
A) Respiratory alkalosis
B) Metabolic acidosis
C) Respiratory acidosis (correct answer)
D) Metabolic alkalosis
**Rationale:** Elevated PaCO2 with low pH indicates respiratory acidosis,
common in COPD exacerbations.
**4. A 30-year-old man presents with bloody diarrhea, abdominal pain, and
tenesmus. Colonoscopy shows continuous inflammation from rectum to sigmoid.
What is the diagnosis?**
A) Crohn's disease
B) Ulcerative colitis (correct answer)
C) Ischemic colitis
D) Diverticulitis
,**Rationale:** Continuous inflammation starting at the rectum is characteristic of
ulcerative colitis.
**5. A 55-year-old woman presents with sudden onset severe headache
("thunderclap"), neck stiffness, and photophobia. CT head is negative. What is the
next best step?**
A) MRI brain
B) Lumbar puncture (correct answer)
C) CTA head
D) EEG
**Rationale:** CT may miss subarachnoid hemorrhage in first 6 hours; LP is
essential for xanthochromia detection.
**6. A 2-year-old child presents with fever, stridor, and barking cough. What is the
most likely diagnosis?**
A) Epiglottitis
B) Croup (correct answer)
C) Bronchiolitis
D) Asthma
**Rationale:** Barking cough and stridor in a toddler is classic for croup
(laryngotracheobronchitis).
, **7. A 40-year-old man presents with polyuria, polydipsia, and weight loss.
Random glucose is 18 mmol/L. What is the diagnostic criterion for diabetes?**
A) Fasting glucose >7.0 mmol/L on two occasions
B) HbA1c >6.5%
C) Random glucose >11.1 mmol/L with symptoms (correct answer)
D) All of the above
**Rationale:** All are valid diagnostic criteria. The random glucose with classic
symptoms confirms diabetes.
**8. A 25-year-old woman presents with joint pain, malar rash, and oral ulcers.
ANA is positive. What is the most specific antibody?**
A) Anti-Ro
B) Anti-dsDNA (correct answer)
C) Anti-Smith
D) Anti-histone
**Rationale:** Anti-dsDNA is highly specific for systemic lupus erythematosus.
**9. A 60-year-old man presents with painless hematuria. CT urogram shows a
filling defect in the bladder. What is the most likely diagnosis?**
Examination Part I MCCQE1 EXAM 2026
**1. A 45-year-old man presents with crushing chest pain radiating to his left arm.
ECG shows ST elevation in leads V1-V4. Which artery is most likely occluded?**
A) Right coronary artery
B) Left circumflex artery
C) Left anterior descending artery (correct answer)
D) Posterior descending artery
**Rationale:** ST elevation in V1-V4 indicates anteroseptal MI, typically caused
by LAD occlusion.
**2. A 28-year-old woman presents with fatigue, pallor, and pica (eating ice). CBC
shows microcytic hypochromic anemia. What is the most likely diagnosis?**
A) Vitamin B12 deficiency
B) Iron deficiency anemia (correct answer)
C) Thalassemia
D) Sickle cell anemia
,**Rationale:** Microcytic hypochromic anemia with pica is classic for iron
deficiency.
**3. A 65-year-old man with COPD presents with worsening dyspnea, increased
sputum production, and fever. Arterial blood gas shows pH 7.30, PaCO2 65 mmHg,
PaO2 55 mmHg. What is the primary acid-base disturbance?**
A) Respiratory alkalosis
B) Metabolic acidosis
C) Respiratory acidosis (correct answer)
D) Metabolic alkalosis
**Rationale:** Elevated PaCO2 with low pH indicates respiratory acidosis,
common in COPD exacerbations.
**4. A 30-year-old man presents with bloody diarrhea, abdominal pain, and
tenesmus. Colonoscopy shows continuous inflammation from rectum to sigmoid.
What is the diagnosis?**
A) Crohn's disease
B) Ulcerative colitis (correct answer)
C) Ischemic colitis
D) Diverticulitis
,**Rationale:** Continuous inflammation starting at the rectum is characteristic of
ulcerative colitis.
**5. A 55-year-old woman presents with sudden onset severe headache
("thunderclap"), neck stiffness, and photophobia. CT head is negative. What is the
next best step?**
A) MRI brain
B) Lumbar puncture (correct answer)
C) CTA head
D) EEG
**Rationale:** CT may miss subarachnoid hemorrhage in first 6 hours; LP is
essential for xanthochromia detection.
**6. A 2-year-old child presents with fever, stridor, and barking cough. What is the
most likely diagnosis?**
A) Epiglottitis
B) Croup (correct answer)
C) Bronchiolitis
D) Asthma
**Rationale:** Barking cough and stridor in a toddler is classic for croup
(laryngotracheobronchitis).
, **7. A 40-year-old man presents with polyuria, polydipsia, and weight loss.
Random glucose is 18 mmol/L. What is the diagnostic criterion for diabetes?**
A) Fasting glucose >7.0 mmol/L on two occasions
B) HbA1c >6.5%
C) Random glucose >11.1 mmol/L with symptoms (correct answer)
D) All of the above
**Rationale:** All are valid diagnostic criteria. The random glucose with classic
symptoms confirms diabetes.
**8. A 25-year-old woman presents with joint pain, malar rash, and oral ulcers.
ANA is positive. What is the most specific antibody?**
A) Anti-Ro
B) Anti-dsDNA (correct answer)
C) Anti-Smith
D) Anti-histone
**Rationale:** Anti-dsDNA is highly specific for systemic lupus erythematosus.
**9. A 60-year-old man presents with painless hematuria. CT urogram shows a
filling defect in the bladder. What is the most likely diagnosis?**
