Pass the Medical Council of Canada MCCQE Part 1 MCCQE Questions and answers with ValidTests

The most important pre-vaccination history to elicit is any previous anaphylaxis to vaccine components. mRNA COVID-19 vaccines (e.g., Pfizer-BioNTech and Moderna) may contain polyethylene glycol (PEG), a potential allergen. This is a contraindication to administration.

Toronto Notes 2023 – Infectious Disease & Immunization Chapter:

“Absolute contraindications to mRNA COVID-19 vaccination include a documented anaphylactic reaction to a component of the vaccine such as polyethylene glycol (PEG).”

MCCQE1 Objectives – Population Health > Preventive Medicine > Immunizations:

“The candidate must be able to assess for contraindications prior to immunization, including anaphylaxis to previous vaccines or components.”

Breastfeeding and occupational exposure (Options B and D) do not preclude vaccination. Current immunosuppression (Option C) may affect vaccine efficacy but is not a contraindication unless specifically advised.

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Comprehensive and Detailed Explanation:

At 20 weeks’ gestation, the uterine fundus typically reaches the umbilicus. If the fundal height is lower than expected at a stated gestational age of 26 weeks, the most likely explanation—especially with no prior care—is a dating error.

Toronto Notes 2023 – Obstetrics:

“Fundal height at the umbilicus corresponds to ~20 weeks. In women lacking early prenatal care, dating errors are common causes of fundal height discrepancy.”

MCCQE1 Objectives (Obstetrics > 80-3: Routine Antenatal Care):

“Candidates must interpret fundal height and reconcile discrepancies with gestational age.”

IUGR and oligohydramnios are possible but require imaging confirmation. Bicornuate uterus may cause fundal shape anomalies but not significant dating discrepancy. A mole (D) would increase, not decrease, size.

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Scaphoid fractures are often radiographically occult on initial presentation and can present later with persistent pain and swelling in the anatomical snuffbox. They typically occur following a fall on an outstretched hand. If missed, they can lead to avascular necrosis.

Toronto Notes 2023 – Orthopedics, Wrist Injuries:

“Scaphoid fractures are the most common carpal fractures. X-rays may be negative early, so high suspicion requires immobilization and repeat imaging after 10–14 days.”

MCCQE1 Objectives – Surgery > Musculoskeletal Trauma:

“Candidates must recognize that some fractures, such as scaphoid, may not appear on initial imaging but require clinical suspicion and follow-up imaging or immobilization.”

Other options (B and C) are less likely without radiographic evidence. De Quervain tenosynovitis (D) presents with radial wrist pain unrelated to trauma and worsens with thumb movement.

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The patient has clinical evidence of genital warts (condyloma acuminata), which are caused by low-risk HPV types. Even though she is not currently sexually active and has visible warts, HPV vaccination is still beneficial for protection against other oncogenic strains (especially types 16 and 18). Vaccination is safe and recommended up to age 45.

Toronto Notes 2023 – Gynecology, "STIs and HPV":

“Vaccination is recommended up to age 45, regardless of prior exposure or visible warts. It may prevent reinfection with or acquisition of high-risk HPV strains.”

MCCQE1 Objectives (Gynecology > 83-3: STIs and HPV):

“Candidates must counsel patients appropriately on prevention, including the role of HPV vaccination, even after exposure or infection.”

Pap testing (B) is routine screening, not management of visible warts. Cryotherapy (D) is optional if the patient desires removal, but she declined treatment. Biopsy (A) is reserved for atypical lesions. Contact tracing (E) is not typically required for HPV warts.

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This patient presents with fever, confusion, anemia with schistocytes, thrombocytopenia, and renal impairment — fulfilling the classic pentad of thrombotic thrombocytopenic purpura (TTP). TTP is a hematologic emergency requiring plasma exchange.

Toronto Notes 2023 – Hematology, “Microangiopathic Hemolytic Anemia” Section:

“TTP is a medical emergency. Features include MAHA, thrombocytopenia, renal failure, neurologic symptoms, and fever. Schistocytes on blood film are diagnostic.”

MCCQE1 Objectives (Internal Medicine > 76-7: Hematologic Disorders):

“Candidates must urgently recognize TTP and initiate emergent plasma exchange therapy.”

AML (B) does not present with schistocytes. HIV (C) can cause thrombocytopenia but not MAHA. ITP (D) causes isolated thrombocytopenia without anemia or schistocytes.

Comprehensive and Detailed Explanation:

This patient has secondary amenorrhea, galactorrhea, and worsening headaches—suggestive of hyperprolactinemia, possibly due to a pituitary adenoma (prolactinoma). Visual field defects (typically bitemporal hemianopia) can result from optic chiasm compression.

Toronto Notes 2023 – Endocrinology / Reproductive Health:

“Prolactinomas may cause amenorrhea, galactorrhea, headaches, and visual field defects. Evaluate with serum prolactin and visual field testing.”

MCCQE1 Objectives (Endocrinology > 37-2: Pituitary Disorders):

“Candidates must recognize clinical signs of prolactinomas and know when to assess visual fields.”

Hirsutism (D) suggests androgen excess. Low BMI (B) can cause hypothalamic amenorrhea but wouldn’t explain galactorrhea. Nodular breast findings (A) are not related.

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Anaphylaxis requires immediate administration of epinephrine via the intramuscular (IM) route, typically in the lateral thigh. This route provides the fastest and most reliable absorption for emergency treatment.

Toronto Notes 2023 – Pediatrics, Anaphylaxis:

“Epinephrine 0.01 mg/kg IM is the first-line treatment for anaphylaxis. The intramuscular route provides the most rapid and safe absorption in emergencies.”

MCCQE1 Objectives – Pediatrics > Allergy and Immunology:

“Candidates must know the emergency management of anaphylaxis, including proper dosage and intramuscular administration of epinephrine.”

IV administration (A) is reserved for critical care settings. Subcutaneous (C) and intranasal/inhaled routes (D, E) are ineffective in anaphylaxis.

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This patient is experiencing mild hypothermia (32–35°C), evidenced by shivering, ataxia, and tachycardia. First-line management includes passive external rewarming — removing wet clothing, providing warm blankets, and ensuring a warm environment (ambient temperature ~28°C).

Toronto Notes 2023 – Emergency Medicine, Environmental Injuries:

“Mild hypothermia (32–35°C): Treatment includes passive rewarming (warm blankets, warm environment). Avoid active rewarming methods to extremities due to risk of afterdrop.”

MCCQE1 Objectives – Internal Medicine > Environmental Exposure:

“Candidates must recognize appropriate levels of hypothermia and select evidence-based rewarming strategies based on severity.”

Options A, C, and D are used in moderate to severe hypothermia (<32°C or unconscious patients). Heating pads (B) may cause tissue damage, especially with frostbite.

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Comprehensive and Detailed Explanation:

Bronchiectasis is characterized by recurrent localized pneumonia, chronic productive cough, and hemoptysis. A linear infiltrate that persists in the same area suggests localized airway damage—typical of bronchiectasis.

Toronto Notes 2023 – Respirology:

“Bronchiectasis presents with recurrent infections in the same location, productive cough, and hemoptysis. Chest X-ray may show linear opacities; high-resolution CT is diagnostic.”

MCCQE1 Objectives (Respiratory > 45-1: Chronic Respiratory Symptoms):

“Candidates must investigate recurrent pneumonias and consider bronchiectasis, especially if localized.”

Chronic bronchitis (A) presents bilaterally. Mitral stenosis (B) may cause hemoptysis but not localized infiltrates. TB (E) usually affects upper lobes. Infarction (C) is acute and not recurrent.

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This is a classic presentation of diabetic peripheral neuropathy: bilateral distal sensory symptoms with preserved motor function and no other systemic findings. The most useful test to confirm this in a previously undiagnosed patient is HbA1c.

Toronto Notes 2023 – Endocrinology, Diabetes Complications:

“Peripheral neuropathy is a common complication of undiagnosed or poorly controlled diabetes. Confirm with HbA1c if diagnosis is not yet established.”

MCCQE1 Objectives – Internal Medicine > Endocrinology:

“Candidates should evaluate for diabetes in patients with peripheral neuropathy and screen appropriately with HbA1c.”

Folate (B) and B12 deficiency may also cause neuropathy but are less likely in the absence of nutritional risk factors. Other choices (A, D, E) are unrelated to this pattern.

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