A 45-year-old woman presents with a thyroid nodule and chronic diarrhea. Serum calcitonin is markedly elevated. Which tumor marker is characteristically elevated in the majority of patients with this diagnosis and is used for postoperative surveillance?
- A Thyroglobulin
- B Chromogranin A
- C Carcinoembryonic antigen (CEA) ✓
- D Parathyroid hormone
Correct answer: C. Carcinoembryonic antigen (CEA)
Explanation
Medullary thyroid carcinoma arises from parafollicular B cells and secretes calcitonin. CEA is also characteristically elevated and is used alongside calcitonin for postoperative monitoring. Thyroglobulin is a marker for follicular or papillary thyroid carcinoma. Chromogranin A is a general neuroendocrine marker. PTH is elevated in primary hyperparathyroidism.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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