A rare phenomenon in thyroid neoplasms: Collision tumor

Abstract

The combination of two or more histologically distinct tumor components occurring at the same anatomic location is called a collision tumor and is a rare occurrence in the thyroid gland. Most often both the tumors are malignant and combinations of papillary-follicular carcinoma, papillary-medullary carcinoma are more common. Here, we report a rare collision tumor having Hurthle cell adenoma and papillary microcarcinoma as its components.