Endocrine Surgery (Thyroid, Parathyroid, Adrenal)
Core Concepts
Focus on thyroid nodules, thyroid cancer, hyperparathyroidism, and adrenal incidentalomas. Know the Bethesda system for thyroid cytology and the management of differentiated thyroid cancer (total thyroidectomy, radioactive iodine for high-risk). Understand primary hyperparathyroidism: elevated calcium, elevated PTH, and the indications for parathyroidectomy (symptomatic, age <50, calcium >1 mg/dL above normal, osteoporosis, renal stones). For adrenal masses, evaluate for hormonal function and malignancy (size >4 cm, imaging characteristics).
Traps in Questions
A common trap is the evaluation of thyroid nodules: ultrasound features (microcalcifications, irregular margins) increase suspicion; fine-needle aspiration (FNA) is indicated for nodules ≥1 cm with suspicious features. Another trap is the use of intraoperative PTH monitoring during parathyroidectomy: a drop of >50% indicates successful removal. For adrenal incidentalomas, beware of the “non-functional” mass that is actually a pheochromocytoma – always screen with plasma metanephrines. Also, know that thyroid cancer in a young patient is usually papillary and has a good prognosis.
Worked Example
A 45-year-old woman with a 2 cm thyroid nodule, Bethesda IV cytology. What is the next step? Answer: Diagnostic lobectomy (or total thyroidectomy if bilateral).
Rule of Thumb
In primary hyperparathyroidism, surgery is indicated for any symptoms, age <50, calcium >1 mg/dL above upper limit, or T-score < -2.5.