In medullary thyroid carcinoma (MTC), which tumor marker is most useful for monitoring disease recurrence after total thyroidectomy?

• A Thyroglobulin
• B CEA (carcinoembryonic antigen)
• C Serum calcium
• D Calcitonin ✓

Explanation

Calcitonin, produced by parafollicular C-cells from which MTC originates, is the primary tumor marker for monitoring MTC after total thyroidectomy. CEA is also elevated in MTC and correlates with tumor burden, but calcitonin is more specific and sensitive. Thyroglobulin is specific for follicular cell-derived thyroid cancers (papillary and follicular), not MTC. Provocative calcitonin testing with pentagastrin or calcium can detect microscopic residual disease. The calcitonin doubling time has strong prognostic value.

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.