MRCP Part 1 Endocrinology and Nephrology

Question 1

A 35-year-old woman presents with weight gain, moon face, abdominal striae, and proximal myopathy. Her 24-hour urinary free cortisol is elevated. What is the next most appropriate investigation?

Accepted Answer

Overnight dexamethasone suppression test

Answer

After confirming hypercortisolism with elevated urinary free cortisol, the next step is to perform a low-dose (1 mg) overnight dexamethasone suppression test to confirm Cushing's syndrome. Failure to suppress cortisol (<50 nmol/L) confirms the diagnosis. ACTH levels are then measured to determine the cause.

Question 2

A patient with type 2 diabetes has an eGFR of 35 mL/min/1.73m2 and persistent albuminuria (ACR 45 mg/mmol) despite maximal ACE inhibitor therapy. According to NICE, which additional medication should be considered?

Accepted Answer

SGLT2 inhibitor (dapagliflozin)

Answer

NICE recommends SGLT2 inhibitors (dapagliflozin) for patients with type 2 diabetes and CKD with ACR >=30 mg/mmol, regardless of HbA1c level. The DAPA-CKD trial demonstrated significant renal and cardiovascular benefits. They can be used down to eGFR 15 mL/min for renoprotection.

Question 3

A 28-year-old woman presents with a thyroid nodule. Fine needle aspiration cytology is reported as Thy3f (follicular neoplasm). What is the recommended management?

Accepted Answer

Diagnostic hemithyroidectomy

Answer

Thy3f cytology indicates a follicular neoplasm which cannot be distinguished from follicular carcinoma on cytology alone — capsular and vascular invasion can only be assessed on histological examination. Diagnostic hemithyroidectomy is recommended to obtain a definitive tissue diagnosis.

Question 4

A patient presents with severe hypercalcaemia (corrected calcium 3.8 mmol/L) causing confusion and dehydration. What is the most important initial treatment?

Accepted Answer

Intravenous 0.9% sodium chloride

Answer

Aggressive IV fluid resuscitation with 0.9% saline is the first priority in severe hypercalcaemia. Patients are typically volume depleted due to hypercalcaemia-induced nephrogenic diabetes insipidus. Rehydration alone can reduce calcium significantly. Bisphosphonates (zoledronic acid) are given once rehydrated but take 2-4 days to work.

Question 5

Which antibody is most specific for type 1 diabetes mellitus?

Accepted Answer

Anti-GAD65 antibodies

Answer

Anti-glutamic acid decarboxylase (anti-GAD65) antibodies are the most commonly tested and most persistent autoantibodies in type 1 diabetes. Other relevant antibodies include IA-2 antibodies and zinc transporter 8 (ZnT8) antibodies. They are useful for confirming autoimmune aetiology, particularly in LADA (latent autoimmune diabetes in adults).

MRCP Part 1 Practice Test

MRCP Part 1 Practice Test

MRCP Part 1 Endocrinology and Nephrology