Radioactive iodine-associated cytomorphologic alterations in thyroid follicular epithelium: Is recognition possible in fine-needle aspiration specimens?

Thyrotoxicosis is a condition resulting from presentation to the body's tis sues of excessive quantities of thyroid hormones. Gr aves' disease is the m ost common cause of thyroid hyperfunction in the United States; this condit ion can be managed effectively by long-term antithyroid drugs, radioactive iodine (I-131) therapy, or surgical intervention. The majority of American physicians prescribe I-131, the most cost-effective therapy, for their pati ents with thyrotoxicosis. These patients who are closely followed for their existing thyroid pathology may be referred for fine needle aspiration of n odules. This review focuses on I-131-associated cytologic changes in thyroi d follicular epithelium in patients previously treated Sor underlying hyper thyroidism. Diagn. Cytopathol. 1999;21:207-210, (C) 1999 Wiley-Liss, Inc.