Diagnostic Accuracy of Fine Needle Aspiration in Thyroid Nodules Arising in Patients with Graves Disease

Objective: Cytopathologic interpretation in Graves disease (GD) is considered challenging due to significant cellular atypia. Study Design: We retrospectively identified 55 fine needle aspirations (FNAs) from 43 patients with GD that subsequently underwent thyroidectomy from 1995 to 2016. Results: There were 5 patients with papillary thyroid carcinoma (PTC) and 4 with follicular adenoma (FA). Of the 5 patients with PTC, FNA was interpreted as PTC in 3, atypia of undetermined significance (AUS) in 1, and adenomatoid nodule (AN) in 1 (with a 0.5-cm incidental microcarcinoma). Of the 4 patients with FA, FNA was interpreted as follicular neoplasm (FN) in 2, AUS in 1, and AN in 1. Of the 46 nonneoplastic nodules, FNA was interpreted as nondiagnostic in 2, benign in 26, AUS in 15, FN in 1, and suspicious for PTC in 2. None was diagnosed as malignant. The sensitivity, specificity, positive predictive value, and negative predictive value of PTC diagnosis in FNA were 60, 100, 100, and 96.2%, respectively. Conclusion: FNA is a useful tool for identifying neoplastic nodules arising in GD. However, cytologic atypia often leads to indeterminate diagnoses (18/46, 39.1%). Awareness of clinical information regarding prior treatment for GD may be helpful to avoid overinterpretation.