A 38-year-old woman has a firm thyroid nodule. Total thyroidectomy shows a tumor composed of nests of spindle-shaped cells with amyloid stroma on Congo red staining. Serum calcitonin was 1200 pg/mL preoperatively. Which pair of markers is most appropriate for postoperative surveillance of this tumor?
- A Thyroglobulin and anti-thyroid peroxidase antibody
- B Parathyroid hormone and chromogranin A
- C Calcitonin and carcinoembryonic antigen ✓
- D Calcitonin and thyroglobulin
Correct answer: C. Calcitonin and carcinoembryonic antigen
Explanation
The amyloid-producing nests of B-cell origin indicate medullary thyroid carcinoma. Its cells secrete both calcitonin and carcinoembryonic antigen, so rising levels of either after surgery signal persistent or recurrent disease. Thyroglobulin is the surveillance marker for papillary and follicular carcinomas, which arise from follicular cells and do not produce calcitonin. Parathyroid hormone relates to parathyroid tumors seen in MEN syndromes but does not track the medullary carcinoma itself.
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.