Optimal timing for a repeat fine-needle aspiration biopsy of thyroid nodule following an initial nondiagnostic fine-needle aspiration.

BACKGROUND: In the case of a nondiagnostic thyroid fine-needle aspiration (FNA) biopsy result, recent guidelines from the Bethesda system recommend repeat thyroid FNA after 3 months to prevent false-positive results. We aimed to examine our institutional data to determine whether the 3-month period affects the diagnostic yield of repeat biopsies.

METHODS: A retrospective review of patient records over a 5-year period at our institution was performed. Patients who required repeat FNA due to nondiagnostic results were included. The time between the FNA biopsies, adequacy of the FNA specimens, as well as the surgical pathology diagnosis were analyzed.

RESULTS: We identified 317 patients who required a repeat FNA. Of these, 96 (30.3%) patients had repeat FNAs less than 3 months after initial biopsy, while 221 (69.7%) patients had repeat FNAs in greater than 3 months. One hundred five patients were referred to our clinic with an initial nondiagnostic biopsy from an outside institution. Repeat FNA was nondiagnostic in 35 patients (11.04%) in the total study population. There was no difference in satisfactory diagnostic yield between repeat FNAs performed greater than 3 months (201 patients, 90.95%) or less than 3 months (81 patients, 84.38%) after the initial biopsy (P = .117). Of the 35 patients with repeat nondiagnostic biopsy, 17 patients underwent diagnostic lobectomy and 3 (17.6%) patients were found to have malignant disease.

CONCLUSIONS: Early (<3 months) repeat FNA does not affect diagnostic yield of the subsequent sample. Patients with suspicious thyroid nodules could therefore receive a repeat FNA as soon as needed, rather than waiting 3 months. The shortened biopsy interval would alleviate stress on patients with benign nodules and expedite surgical intervention in patients with malignancy.