PANCE Endocrine System 2 — Questions and Answers
Question 1: A 45-year-old woman presents with weight gain, cold intolerance, and constipation. TSH is 12 mIU/L and free T4 is low. Which medication is first-line treatment?
- Methimazole
- Levothyroxine (Correct answer)
- Propylthiouracil
- Radioactive iodine
Correct answer: Levothyroxine
Levothyroxine (synthetic T4) is the first-line treatment for hypothyroidism.
Question 2: A patient with type 1 diabetes develops sudden confusion, diaphoresis, and tremors. Blood glucose is 42 mg/dL. What is the most appropriate immediate intervention?
- Administer IV insulin
- Give 15-20g of fast-acting carbohydrates (Correct answer)
- Administer glucagon IM
- Start IV dextrose 50%
Correct answer: Give 15-20g of fast-acting carbohydrates
The rule of 15 (15g fast carbs, recheck in 15 min) is first-line for a conscious hypoglycemic patient.
Question 3: A 52-year-old man has a serum calcium of 11.8 mg/dL, PTH of 95 pg/mL, and is asymptomatic. What is the most likely diagnosis?
- Hypoparathyroidism
- Primary hyperparathyroidism (Correct answer)
- Humoral hypercalcemia of malignancy
- Vitamin D toxicity
Correct answer: Primary hyperparathyroidism
Elevated calcium with elevated (or inappropriately normal) PTH is the hallmark of primary hyperparathyroidism.
Question 4: Which of the following is the most common cause of Cushing syndrome in clinical practice?
- Adrenal adenoma
- Ectopic ACTH production
- Exogenous corticosteroid use (Correct answer)
- Pituitary adenoma (Cushing disease)
Correct answer: Exogenous corticosteroid use
Iatrogenic Cushing syndrome from exogenous glucocorticoid use is the most common cause overall.
Question 5: A 28-year-old woman has amenorrhea, galactorrhea, and a serum prolactin of 120 ng/mL. MRI shows a 7 mm pituitary lesion. First-line treatment is:
- Surgical resection
- Bromocriptine or cabergoline (Correct answer)
- Radiation therapy
- Estrogen replacement
Correct answer: Bromocriptine or cabergoline
Dopamine agonists (cabergoline preferred) are first-line for prolactinomas regardless of size.
Question 6: A patient with known Addison disease presents with severe hypotension and vomiting after a flu illness. Which is the most critical immediate treatment?
- Oral fludrocortisone
- IV hydrocortisone and saline (Correct answer)
- Oral prednisone
- IV dextrose only
Correct answer: IV hydrocortisone and saline
Adrenal crisis requires immediate IV hydrocortisone and aggressive IV fluid resuscitation with normal saline.
Question 7: A 60-year-old man on lithium for 15 years presents with polyuria and polydipsia. Urine osmolality remains low after water deprivation but increases after desmopressin. What is the diagnosis?
- Primary polydipsia
- Nephrogenic diabetes insipidus
- Central diabetes insipidus (Correct answer)
- SIADH
Correct answer: Central diabetes insipidus
Response to desmopressin indicates central (not nephrogenic) DI; lithium can cause nephrogenic DI, but response to ADH analog points to central.
PANCE Endocrine System 2
A 45-year-old woman presents with weight gain, cold intolerance, and constipation.
TSH is 12 mIU/L and free T4 is low.
Which medication is first-line treatment?