AMC MCQ - Australian Medical Council Multiple Choice Questions Amc Mcq/Questions/Practice 1 — Questions and Answers
Question 1: A 45-year-old woman presents with a 3-month history of fatigue, weight gain, constipation, and cold intolerance. Her TSH is 18 mIU/L and free T4 is low. What is the most appropriate initial treatment?
- Levothyroxine (Correct answer)
- Carbimazole
- Prednisolone
- Radioactive iodine
Correct answer: Levothyroxine
The clinical picture and biochemistry are consistent with primary hypothyroidism (elevated TSH, low free T4). Levothyroxine (synthetic T4) is the standard first-line replacement therapy. Carbimazole and radioactive iodine are used for hyperthyroidism; prednisolone would not address the thyroid hormone deficiency.
Question 2: A 72-year-old woman with hypertension and atrial fibrillation is brought in confused and unable to speak. CT head is normal. Her symptoms began 90 minutes ago. What is the most appropriate next step?
- IV tissue plasminogen activator (tPA) (Correct answer)
- Aspirin 300 mg orally
- Urgent MRI brain
- Anticoagulation with heparin
Correct answer: IV tissue plasminogen activator (tPA)
This presentation is consistent with acute ischaemic stroke within the thrombolytic window (within 4.5 hours of onset). CT has excluded haemorrhage. IV tPA is the recommended treatment. Aspirin alone is not adequate in the acute thrombolytic window; heparin is not first-line for acute stroke; MRI is not necessary before thrombolysis if CT is clear.
Question 3: A 30-year-old man presents with painless, firm swelling of the left testis. Serum alpha-fetoprotein is markedly elevated. What is the most likely diagnosis?
- Yolk sac tumour (non-seminomatous germ cell tumour) (Correct answer)
- Classical seminoma
- Epididymo-orchitis
- Testicular torsion
Correct answer: Yolk sac tumour (non-seminomatous germ cell tumour)
Markedly elevated AFP is characteristic of non-seminomatous germ cell tumours, particularly yolk sac tumours. Pure seminomas do not produce AFP. Epididymo-orchitis presents with pain and tenderness. Testicular torsion is an acute painful emergency, not a painless swelling.
Question 4: A 55-year-old man with type 2 diabetes and an eGFR of 28 mL/min/1.73m² is found to have a serum potassium of 6.1 mmol/L and no ECG changes. Which medication should be started as the priority initial management?
- Calcium resonium (sodium polystyrene sulfonate)
- Insulin and dextrose infusion (Correct answer)
- IV calcium gluconate
- Sodium bicarbonate infusion
Correct answer: Insulin and dextrose infusion
Insulin and dextrose rapidly shift potassium intracellularly and is the first-line pharmacological treatment for hyperkalaemia without ECG changes. IV calcium gluconate stabilises the myocardium and is indicated when ECG changes are present. Calcium resonium reduces total body potassium but acts slowly. Bicarbonate has limited evidence in non-acidotic patients.
Question 5: A 3-year-old child presents with a purpuric, non-blanching rash, fever of 39.5°C, and neck stiffness. She appears unwell and drowsy. What is the most critical immediate action?
- IV benzylpenicillin (Correct answer)
- Lumbar puncture
- Blood cultures then await results
- CT head before any treatment
Correct answer: IV benzylpenicillin
This presentation is highly suspicious for meningococcal meningitis/septicaemia. IV benzylpenicillin must be given immediately without waiting for investigations as delay increases mortality. Lumbar puncture and CT may follow after stabilisation and treatment have been initiated, and blood cultures should be taken but must not delay antibiotics.
Question 6: A 28-year-old woman at 10 weeks gestation presents with severe nausea, vomiting, a uterus larger than expected for dates, and serum beta-hCG of 350,000 IU/L. Ultrasound shows a snowstorm appearance with no fetal parts. What is the most likely diagnosis?
- Complete hydatidiform mole (Correct answer)
- Partial hydatidiform mole
- Twin pregnancy
- Choriocarcinoma
Correct answer: Complete hydatidiform mole
The combination of markedly elevated beta-hCG, hyperemesis, uterus large for dates, and snowstorm appearance on ultrasound with absent fetal parts is classic for a complete hydatidiform mole (46,XX karyotype, entirely paternal origin). Partial moles have fetal/embryonic tissue. Choriocarcinoma typically follows a molar or other pregnancy rather than presenting de novo with this ultrasound pattern.
A 45-year-old woman presents with a 3-month history of fatigue, weight gain, constipation, and cold intolerance.
Her TSH is 18 mIU/L and free T4 is low.
What is the most appropriate initial treatment?