A 38-year-old woman undergoes total thyroidectomy for a medullary thyroid carcinoma. Two serum markers are used to follow her for residual or recurrent disease. These markers are:

• A Thyroglobulin and TSH receptor antibody
• B Carcinoembryonic antigen and neuron-specific enolase
• C Calcitonin and thyroglobulin
• D Calcitonin and carcinoembryonic antigen ✓

Explanation

Medullary thyroid carcinoma arises from parafollicular C cells, which secrete calcitonin, and these tumors frequently coexpress carcinoembryonic antigen. Both serve as sensitive markers for detecting residual disease and recurrence after thyroidectomy. Thyroglobulin is the surveillance marker for differentiated papillary and follicular carcinomas because those tumors derive from follicular epithelium, not C cells, making option C the strongest distractor. Neuron-specific enolase belongs to small cell lung cancer and neuroblastoma.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.