PANRE Endocrinology 2 — Questions and Answers
Question 1: A 55-year-old woman with type 2 diabetes has an eGFR of 38 mL/min/1.73m². Which medication should be discontinued?
- Metformin (Correct answer)
- Glipizide
- Sitagliptin
- Insulin glargine
Correct answer: Metformin
Metformin is contraindicated when eGFR falls below 30 and should be used with caution (many guidelines recommend discontinuing) at eGFR <45 due to risk of lactic acidosis.
Question 2: Which finding is most consistent with primary hyperaldosteronism (Conn syndrome)?
- Hyperkalemia with hypertension
- Hypokalemia with hypertension (Correct answer)
- Hyperkalemia with hypotension
- Hyponatremia with hypertension
Correct answer: Hypokalemia with hypertension
Primary hyperaldosteronism causes sodium retention and potassium wasting, resulting in hypokalemia and hypertension.
Question 3: A patient with suspected pheochromocytoma should be screened using which initial test?
- 24-hour urine catecholamines and metanephrines (Correct answer)
- Random serum epinephrine level
- Adrenal CT scan
- ACTH stimulation test
Correct answer: 24-hour urine catecholamines and metanephrines
24-hour urine catecholamines and fractionated metanephrines (or plasma metanephrines) are the recommended biochemical screening tests for pheochromocytoma.
Question 4: A 40-year-old man has central obesity, moon facies, and purple striae. His 24-hour urine free cortisol is elevated. What is the next best step?
- MRI of the pituitary
- Low-dose dexamethasone suppression test (Correct answer)
- CT of the adrenal glands
- High-dose dexamethasone suppression test
Correct answer: Low-dose dexamethasone suppression test
After confirming hypercortisolism with elevated urine free cortisol, a low-dose dexamethasone suppression test helps confirm the diagnosis of Cushing syndrome before localization.
Question 5: Which thyroid cancer subtype has the worst prognosis?
- Papillary
- Follicular
- Medullary
- Anaplastic (Correct answer)
Correct answer: Anaplastic
Anaplastic (undifferentiated) thyroid carcinoma is extremely aggressive with median survival of only 3-5 months after diagnosis.
Question 6: A patient with MEN2A would most likely have which combination of conditions?
- Medullary thyroid cancer, pheochromocytoma, and hyperparathyroidism (Correct answer)
- Papillary thyroid cancer, pituitary adenoma, and pancreatic tumor
- Parathyroid adenoma, insulinoma, and gastrinoma
- Adrenal adenoma, pheochromocytoma, and prolactinoma
Correct answer: Medullary thyroid cancer, pheochromocytoma, and hyperparathyroidism
MEN2A (Multiple Endocrine Neoplasia type 2A) is characterized by medullary thyroid carcinoma, pheochromocytoma, and primary hyperparathyroidism.
Question 7: Which insulin regimen best mimics physiologic insulin secretion in type 1 diabetes?
- Once-daily NPH insulin
- Twice-daily premixed 70/30 insulin
- Basal-bolus regimen with glargine plus rapid-acting insulin (Correct answer)
- Sliding scale regular insulin only
Correct answer: Basal-bolus regimen with glargine plus rapid-acting insulin
A basal-bolus regimen using long-acting insulin (e.g., glargine) for basal needs and rapid-acting insulin at meals best approximates normal pancreatic insulin secretion.
PANRE Endocrinology 2
A 55-year-old woman with type 2 diabetes has an eGFR of 38 mL/min/1.73m².
Which medication should be discontinued?