Diagnostic Value of Fine-Needle Aspiration Cytology in the Operative Management of Thyroid Nodules

ABSTRACT

PURPOSE: Fine-needle aspiration cytology (FNA) and frozen section biopsy (FS) have been used for the purpose of distinguishing benign lesions from malignancies and for deciding the operative procedures to be used in the management of the thyroid nodules. We performed this study the diagnostic value of the FNA, the need for the FS in intraoperative procedures, and to determine their values in deciding the extent of surgery. METHODS: The medical records of 365 consecutive patients who had undergone surgery for thyroid nodules at the Department of Surgery, Hanyang University Hospital, between Jan. 1996 and Dec. 1998 were reviewed retrospectively. FNA and FS were performed on all patients who underwent thyroid surgery during this period. Among them, 35 patients who were diagnosed as insufficient for diagnosis by FNA were excluded. RESULTS: Definitive histopathological diagnosis revealed benign lesions in 232 patients and malignancies in 98. A borderline group consisted of patients whose specimen were interpreted as follicular neoplasms by FNA and FS. Overall results for FNA and FS were sensitivity, 98 versus 100; specificity, 97 versus 99; diagnostic accuracy, 97 versus 99%. Five patients who were diagnosed with benign lesions by FNA were rediagnosed by FS as having malignant lesions. The tinal diagnosis was a papillary carcinoma. Of the 45 patients who were interpreted borderline by FNA, 7 patients had benign lesions, and 38 were borderline by FS. Finally, 34 patients were diagnosed as having benign lesions and 11 as having malignancies. CONCLUSION: FNA has a high diagnostic accuracy for differentiatve diagnosis in the thyroid nodules. FS may be unnecessary for patients whose FNA results indicate malignancy especially papillary carcinoma, so routine use of FS for patients who were diagnosed as having a papillary carcinoma by FNA may be omitted. If FNA results are borderline, FS may be helpful to confirm a follicular neoplasm. If FNA indicates benign, FS seems to be necessary to decide the extent of surgery.