Coexistence of anaplastic and papillary thyroid carcinomas and diagnostic pitfalls of fine needle aspiration

Abstract

Anaplastic thyroid carcinoma is a highly aggressive thyroid cancer with a dismal prognosis. We report 
a case of anaplastic thyroid carcinoma coexisting with papillary carcinoma. This is an extremely rare 
occurrence and is considered to have negative prognostic significance.