The diagnostic dilemma of follicular variant of papillary thyroid carcinoma.

Overview

BACKGROUND: Given the difference in surgical management between follicular neoplasms and papillary thyroid carcinoma (PTC), we sought to determine the sensitivity of fine-needle aspiration (FNA) and intraoperative pathologic study (IP), frozen section and cytologic study, in establishing a diagnosis of follicular variant of papillary thyroid carcinoma (FVPTC) and how these techniques impact operative management. METHODS: A retrospective chart review was performed of patients who underwent thyroidectomy for nodular disease between June 1997 and June 2002 identifying patients with a final diagnosis of FVPTC. FNA and IP results were reviewed in this group of patients and correlated with those of final histopathologic study. The sensitivity of FNA and IP was calculated. RESULTS: Eighty-two patients had a final diagnosis of FVPTC. Eighty-six preoperative FNAs were obtained in 80 patients, leading to a diagnosis of PTC in 7 (sensitivity 9%). Intraoperative pathologic study was performed in 31 patients with suspicious FNA results, of which 13 were definitive for PTC (sensitivity 42%). Overall, IP was obtained in 42 patients, of which 15 were positive for PTC (sensitivity 36%). CONCLUSION: Although the sensitivity of FNA in establishing a diagnosis of FVPTC is low, FNA identifies patients with suspicious lesions in whom IP is important in guiding operative management.