Fine-Needle Aspiration Cytology of Papillary Hurthle Cell Carcinoma with Lymphocytic Stroma "Warthin-Like Tumor" of the Thyroid.

Papillary Hurthle cell carcinoma with lymphocytic stroma is a recent addition to the list of variants of papillary carcinoma of the thyroid. We report the aspiration cytology and histology findings of this tumor arising in two patients. The smears were cellular, and revealed Hurthle cells arranged in three-dimensional groups, papillary fragments, and as singly dispersed cells with a prominent intimately associated inflammatory component of lymphocytes and few plasma cells. The Hurthle cells were pleomorphic and showed granular eosinophilic cytoplasm, eccentrically oriented nuclei with prominent nucleoli. Nuclear features of papillary carcinoma were present among both the cellular groups and scattered cells. The histologic examination showed a circumscribed papillary tumor comprising Hurthle cells and a brisk inflammatory component filling the stalks of papillae, These findings were consistent with a papillary Hurthle cells carcinoma with lymphocytic stroma, the so-called Warthin-like tumor of the thyroid. Hurthle cells admixed with inflammatory cells in cytology preparations can be seen in Hurthle cell nodules or neoplasms arising in a background of chronic lymphocytic thyroiditis. We suggest that a careful search for nuclear features may be helpful in diagnosing this variant of papillary carcinoma.