A Case Report of Synchronous Medullary and Papillary Thyroid Carcinoma with Bilateral Lymph Node Metastasis

Papillary thyroid carcinoma (PTC) and medullary thyroid carcinoma (MTC) are two distinct types of thyroid carcinoma that have different origins. An association between medullary and papillary thyroid cancer is rare and occurs as either discrete lesions or as a mixed lesion. We present the case of a patient diagnosed with synchronous medullary and PTC with bilateral lymph node metastasis.

A 36-year-old man had a follow-up checkup because over the last year his serum carcinoembryonic antigen (CEA) levels had been elevated. During a thyroid examination, nodules were palpable on both sides of his thyroid gland. Ultrasound-guided fine needle aspiration showed PTC of the right lobe of the thyroid but a diagnosis could not be made for the sample from the left lobe. Total thyroidectomy was performed and after surgery, the synchronous MTC and PTC diagnosis was confirmed using the pathologic findings.

From the pathology findings after surgery, the patient was diagnosed with synchronous MTC and PTC with bilateral lymph node metastasis. We recommend paying more attention to the synchronous emergence of these thyroid tumors in men in order to avoid misdiagnoses.