Dual lesions in thyroidectomy, unravelling the enigma of thyroid collision tumors: A rare case report

Follicular adenoma (FA) of the thyroid gland is a benign, solitary, encapsulated tumor. It shows microfollicular and macrofollicular growth patterns. Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy and follicular variant is the most common subtype of PTCs. They have tumor cells arranged in follicular pattern which exhibit nuclear features of papillary carcinoma. Here we present a remarkable case of a patient who was clinically diagnosed as multinodular goiter, TIRADS 2 (not suspicious) by ultrasonography and Fine needle aspiration cytology report was given as a benign adenomatoid nodule. However, histopathological examination revealed the unexpected coexistence of both follicular adenoma and PTC.