Abstract

Fine needle aspiration cytologic features of a case of insular carcinoma of the thyroid in a 23-year-old woman who presented a palpable neck mass is described. The aspirate showed cellular smear arranged in trabeculae, solid or loose clusters, and microfollicles in necrotic background. The tumor cells had uniform, small round, hyperchromatic nuclei. The chromatin was finely granular, and nuclear membrane was smooth. Nucleoli were not discernible. Nuclear pleomorphism was minimal. The cytoplasm was usually scanty, pale, poorly outlined, and almostly amphophilic. Sometimes paranuclear cytoplasmic vacuoles were noted. Final diagnosis was confirmed by total thyroidectomy as insular carcinoma.

• Keywords: Thyroid;Aspiration cytology;Insular carcinoma;Poorly differentiated carcinoma