DOI: 10.36347/sjmcr.2024.v12i05.075

Pages: 866-870

Medullary thyroid carcinoma (MTC) is a rare malignant tumor, which accounts for <5% of all thyroid malignancies, derived from parafollicular C cells. Hashimoto’s thyroiditis, which is the most common cause of hypothyroidism is an autoimmune disease. Many studies have been done in association with Hashimoto’s thyroiditis, Papillary thyroid carcinoma and thyroid lymphomas. Very few cases of Hashimoto’s thyroiditis with coexisting medullary thyroid carcinoma have been reported, because of its rarity. MTC produces various tumor biomarkers mainly Calcitonin, Carcinoembryonic antigen (CEA) and Chromogranin A. For determining the severity of the condition, preoperative serum calcitonin and CEA values are crucial. Postoperatively, Serum levels of calcitonin and CEA can be used to assess for distant metastases and recurrence. Here we present a rare case of Medullary thyroid carcinoma coexisting with Hashimoto’s thyroiditis.