Fine needle aspiration cytology of warthin-like tumor of the thyroid

Abstract

Oncocytic change in the thyroid may be encountered in a variety of nonneoplastic and neoplastic lesions. Neoplastic thyroid lesions that display prominent H\ufcrthle cell features include H\ufcrthle cell adenoma, H\ufcrthle cell follicular carcinoma and oncocytic variants of papillary, insular and medullary carcinomas.1 Oncocytic papillary H\ufcrthle cell carcinoma is characterized by complex, branching papillae in which oncocytic cells cover thin, fibrovascular, stromal cores.2 Its incidence is reported to be 1\u9611%, with an age range of 8\u9675 years and a male:female ratio of 5.6:1.0.3,4 The clinical behavior of this tumor varies depending on whether the tumor is encapsulated or widely invasive.4 Based on the common existence of ret/PTC gene rearrangement, recent data suggest a possible pathogenetic link between this tumor and Hashimoto\u92s thyroiditis.1 Warthin-like tumor of the thyroid, or H\ufcrthle cell papillary carcinoma with lymphocytic stroma, is a recent addition to the list of variants of papillary carcinoma and is characterized by cystic change and lymphocytic infiltrate in the cores of neoplastic papillae. The term Warthin-like tumor is derived from the tumor\u92s striking histologic resemblance to papillary cystadenoma lymphomatosum of the salivary gland.1,2,5,6 Generally this tumor has an excellent prognosis.2 As for the cytologic diagnosis, there have been only rare reports of cases diagnosed on fine needle aspiration cytology.6 Below we document another case, describing the cytologic features