Grave's disease. Appearance in cytologic smears from fine needle aspirates of the thyroid gland.

The cytomorphologic features were analyzed in thyroid samples obtained by fine needle aspiration (FNA) from 54 cases proven to be Grave's disease (toxic goiter) by a multiparameter study. A fire-flare appearance of the follicular cells and a good cellularity of the smears were the features most frequently observed in these cases. Hürthle cell changes were present in 47% of the cases, and small numbers of lymphocytes were seen in smears from 41% of the cases. Epithelioid cell granulomata and multinucleated giant cells were observed in less than one-fourth of the cases. About half of the cases showed some degree of pleomorphism of the follicular cells. Twenty cases of toxic multinodular goiter were similarly analyzed; the features that distinguished this entity from Grave's disease were the absence of epithelioid cells and multinucleated giant cells in the FNA smears.