Concurrent papillary and medullary thyroid carcinomas with mixed metastases to lymph nodes.

We report here a rare concurrence of medullary and papillary carcinomas of the thyroid in a 39-year-old Saudi male. He presented with a solitary nodule of the right thyroid lobe and underwent total thyroidectomy based on the cytological diagnosis of papillary carcinoma. Subsequent detailed histopathologic examination of the thyroid revealed 2 different types of malignancies in the 2 lobes papillary cancer in the right and medullary cancer in the left lobe. A single small lymph node showed metastatic replacement by both cancers. The extreme rarity and the interesting pathological features of such combinations are discussed.