MRCP Part 1 Endocrinology and Nephrology 2

Question 1

A 50-year-old woman presents with lethargy, weight gain, and constipation. TSH is 45 mU/L (normal 0.4-4.0) and free T4 is 4 pmol/L (normal 9-25). Anti-TPO antibodies are strongly positive. What is the most likely diagnosis?

Accepted Answer

Hashimoto's thyroiditis

Answer

Hashimoto's thyroiditis is the commonest cause of hypothyroidism in the UK. The markedly elevated TSH with low free T4 confirms primary hypothyroidism, and strongly positive anti-thyroid peroxidase (anti-TPO) antibodies confirm autoimmune aetiology. Treatment is lifelong levothyroxine.

Question 2

A 45-year-old man presents with episodic headaches, sweating, and palpitations. His blood pressure is 220/130 mmHg. 24-hour urine metanephrines are markedly elevated. What is the diagnosis?

Accepted Answer

Phaeochromocytoma

Answer

Phaeochromocytoma presents with the classic triad of episodic headaches, sweating, and palpitations with paroxysmal hypertension. Elevated urinary metanephrines confirm catecholamine excess. It must be excluded before any surgery, and alpha-blockade (phenoxybenzamine) must precede beta-blockade to prevent hypertensive crisis.

Question 3

A patient with end-stage renal disease on haemodialysis has a PTH of 85 pmol/L (normal 1.6-6.9), low calcium, and high phosphate. What is this condition called?

Accepted Answer

Secondary hyperparathyroidism (renal osteodystrophy)

Answer

Secondary hyperparathyroidism occurs in CKD due to phosphate retention, reduced 1,25-dihydroxyvitamin D production, and hypocalcaemia. The parathyroid glands respond appropriately by increasing PTH secretion. Management includes phosphate binders, active vitamin D (alfacalcidol), and cinacalcet if refractory.

Question 4

A 25-year-old woman presents with polyuria, polydipsia, and a random plasma glucose of 22 mmol/L. Urine dipstick shows glucose 3+ and ketones 3+. Blood gas shows pH 7.15, bicarbonate 8 mmol/L. What is the initial fluid replacement?

Accepted Answer

0.9% sodium chloride 1 litre over 1 hour

Answer

In diabetic ketoacidosis (DKA), initial fluid resuscitation is with 0.9% sodium chloride. The JBDS DKA guideline recommends 1 litre of 0.9% saline over the first hour, followed by a fixed-rate IV insulin infusion at 0.1 units/kg/hour. 5% dextrose is added later when glucose falls below 14 mmol/L.

Question 5

A 55-year-old man with type 2 diabetes has a urine ACR of 8 mg/mmol on two consecutive samples. His blood pressure is 142/88 mmHg. According to NICE, what is the first-line antihypertensive?

Accepted Answer

ACE inhibitor (ramipril)

Answer

NICE recommends an ACE inhibitor (or ARB if not tolerated) as first-line antihypertensive in diabetic patients with microalbuminuria (ACR 3-30 mg/mmol), regardless of age or ethnicity. ACE inhibitors reduce intraglomerular pressure and slow progression of diabetic nephropathy.

MRCP Part 1 Practice Test

MRCP Part 1 Practice Test

MRCP Part 1 Endocrinology and Nephrology 2