The Utility of Fine-Needle Aspiration in the Diagnosis and Management of Follicular Thyroid Neoplasms:One Institution’s 10-Year Experience

Background: Classical teaching dictates that follicular adenoma (FA) can be distinguished from follicular carcinoma (FC) based on histologic features only. We retrospectively reviewed our institution’s 10-year experience in the use of fine-needle aspiration (FNA) to diagnose follicular thyroid neoplasms. Methods: Patients who had FNA of a thyroid neoplasm from 2000 to 2010 were reviewed. Diagnoses of FA, FC, or follicular neoplasm-not otherwise specified (NOS) were included. Cytopathological results were correlated with surgical pathology. Results: Of 138 patients, 65% underwent surgery. FNA diagnosis for FA had a sensitivity of 50% and specificity of 71%. 25% of patients with an FNA diagnosis of FA were found to have cancer after surgical specimen examination. FNA diagnosis for FC had a sensitivity of 60% and specificity of 94%. Conclusions: FNA has a low sensitivity for diagnosing FA. Surgical pathology remains the gold standard for differentiating follicular carcinoma from adenoma.