Endocrine System
Core concepts
Endocrine surgery questions center on thyroid, parathyroid, adrenal, and pancreatic neuroendocrine disease. Know the workup of a thyroid nodule (TSH, ultrasound, fine-needle aspiration), the significance of medullary thyroid carcinoma (RET, MEN2), and the presentation of primary hyperparathyroidism (hypercalcemia, elevated PTH, osteoporosis, stones). Understand pheochromocytoma preoperative preparation and adrenal incidentaloma evaluation.
Traps
- Thyroid nodule workup: check TSH first; a suppressed TSH suggests a hyperfunctioning nodule and changes the diagnostic path. Ultrasound features and FNA guide management.
- Medullary thyroid cancer: not driven by TSH; screen for RET mutations and associated MEN2 syndromes. Don't treat it like differentiated cancer.
- Pheochromocytoma: never operate without alpha blockade first; unopposed alpha stimulation during induction can cause hypertensive crisis.
- Primary hyperparathyroidism: PTH is inappropriately normal or elevated despite hypercalcemia; distinguish from malignancy-associated hypercalcemia where PTH is suppressed.
Rule of thumb
For an adrenal mass with hypertension and episodic symptoms, screen with plasma metanephrines; if positive, alpha-blockade precedes any surgery.
Worked example
A patient with recurrent kidney stones, bone pain, and elevated calcium: check PTH. Elevated or inappropriately normal PTH confirms primary hyperparathyroidism; localize with imaging and plan parathyroidectomy.