Endocrine

Question 1

20F with neck lump, growing over last 12 weeks. Reports intermittent episodes of diarrhea. O/E palpable thyroid nodule. Blood showed hypercalcaemia and genetic test positive for RET oncogene. Most likely diagnosis?

Medullary, papillary, follicular, anaplastic thyroid cancer

Answer 1

Medullary
MEN 2: autosomal dominant with the presence of medullary thyroid cancer + other endocrine tumors (phaeochromocytoma and/or parathyroid adenomas in MEN 2A, pheochromocytoma and mucosal neurinomas in MEN 2B)
- RET found in > 98% of MEN 2
- Primary hyperparathyroidism is a/w MEN 2A

Question 2

30U glargine and 7U novorapid with each meal, what is the insulin sensitivity factor

Answer 2

2
ISF = 100/ total daily insulin dose (amount of the serum blood sugar drops with 1U of insulin over 2-4h)

Question 3

MOA of carbergoline

Answer 3

Stimulate dopamine receptor, inhibit prolactin secretion, reduce size of prolactinoma, decrease GH in people with acromegaly

Question 4

Control BP in pheochromocytoma

Answer 4

Alpha blocker e.g. phenoxybenzamine (start at 40mg -> increase to 80-120mg

Question 5

GLP-1 receptor agonist e.g. exenatide
Side effects

Answer 5

Acute pancreatitis, fatatl haemorrahagic and necrotising type (C/I if previous pancreatitis)

Question 6

Mechanism of Desmopressin

Answer 6

Selective vasopressin V2 receptor agonist in collecting ducts and DCT - positive response