Cytomorphological features of oncocytic variant of papillary thyroid carcinoma with lymphocytic thyroiditis

Abstract

Cytological diagnosis of hurthle cell lesions of thyroid is a diagnostic dilemma. Presence of hurthle cells on fine needle aspiration (FNA) leads to a wide range of differential diagnosis including benign and malignant entities. The oncocytic variant of papillary thyroid carcinoma (PTC) is one entity of the vast list of differentials of which very few cases have been reported to date. We report a case of oncocytic variant of PTC in a 28-year-old female diagnosed on cytomorphology. The findings of FNA smears of the first aspirate were not sufficient for a definitive diagnosis. Repeat FNA was done to rule out the possibility of autoimmune thyroiditis/thyroid neoplasm. The repeat FNA smears showed oncocytic cells present in papillary and loosely cohesive clusters. Many of the cells displayed nuclear features of PTC and the case was finally diagnosed as PTC; oncocytic variant. Thyroidectomy specimen revealed PTC; oncocytic variant with lymphocytic thyroiditis in the surrounding tissue. Thus, in cytology practice, concurrent autoimmune thyroiditis may pose a problem in diagnosis of PTC; oncocytic variant.

Keywords

• cytology
• oncocytes
• papillary thyroid carcinoma