PANCE Endocrine System 3 — Questions and Answers
Question 1: A 35-year-old woman has episodic hypertension, headache, diaphoresis, and palpitations. 24-hour urine shows elevated metanephrines. Which imaging is most appropriate next?
- Ultrasound of the thyroid
- CT or MRI of the abdomen/pelvis (Correct answer)
- Nuclear stress test
- Chest X-ray
Correct answer: CT or MRI of the abdomen/pelvis
CT or MRI of the abdomen/pelvis is used to localize pheochromocytoma after biochemical confirmation.
Question 2: Which electrolyte abnormality is most characteristic of primary hyperaldosteronism (Conn syndrome)?
- Hyperkalemia and hypernatremia
- Hypokalemia and hypertension (Correct answer)
- Hyponatremia and hypotension
- Hyperkalemia and hypotension
Correct answer: Hypokalemia and hypertension
Excess aldosterone causes sodium retention and potassium wasting, producing hypokalemia with hypertension.
Question 3: A 70-year-old woman with osteoporosis is found to have a serum calcium of 10.9 mg/dL and PTH-related peptide (PTHrP) elevated. PTH is suppressed. What is the most likely etiology?
- Primary hyperparathyroidism
- Familial hypocalciuric hypercalcemia
- Humoral hypercalcemia of malignancy (Correct answer)
- Vitamin D intoxication
Correct answer: Humoral hypercalcemia of malignancy
Elevated PTHrP with suppressed PTH in an elderly patient suggests humoral hypercalcemia of malignancy.
Question 4: A patient with type 2 diabetes has an HbA1c of 9.2% and CKD stage 3 (eGFR 38 mL/min). Which medication should be avoided or used with caution?
- Insulin glargine
- Sitagliptin
- Metformin (Correct answer)
- Empagliflozin
Correct answer: Metformin
Metformin is contraindicated when eGFR <30 and requires dose reduction/caution at eGFR 30-45 due to lactic acidosis risk.
Question 5: Graves disease is caused by which mechanism?
- TSH receptor-blocking antibodies
- Thyroid peroxidase antibodies causing hypothyroidism
- Stimulating antibodies against the TSH receptor (Correct answer)
- Destruction of follicular cells by cytotoxic T cells
Correct answer: Stimulating antibodies against the TSH receptor
Thyroid-stimulating immunoglobulins (TSI) bind and activate the TSH receptor, causing hyperthyroidism in Graves disease.
Question 6: A 25-year-old man presents with tall stature, long limbs, lens dislocation, and aortic root dilation. Which endocrine/metabolic condition is associated with this phenotype?
- Acromegaly
- Multiple endocrine neoplasia type 1
- Homocystinuria (Correct answer)
- Klinefelter syndrome
Correct answer: Homocystinuria
Homocystinuria (enzyme deficiency) causes a Marfanoid habitus with lens dislocation downward and thrombotic risk, distinguishing it from Marfan syndrome.
Question 7: A 55-year-old man undergoes thyroidectomy. Postoperatively he develops perioral numbness and carpopedal spasm. Which sign would you elicit?
- Kernig sign
- Chvostek sign (Correct answer)
- Cullen sign
- Rovsing sign
Correct answer: Chvostek sign
Chvostek sign (facial twitch on tapping the facial nerve) indicates hypocalcemia from hypoparathyroidism after thyroidectomy.
PANCE Endocrine System 3
A 35-year-old woman has episodic hypertension, headache, diaphoresis, and palpitations. 24-hour urine shows elevated metanephrines.
Which imaging is most appropriate next?