ROLE OF FINE-NEEDLE ASPIRATION CYTOLOGY AS THE INITIAL MODALITY IN THE INVESTIGATION OF THYROID LESIONS

OBJECTIVE: To study the utility of fine needle aspiration (FNA) cytology as the initial modality in the investigation of thyroid lesions. STUDY DESIGN: Fine needle aspiration biopsies performed on patients presenting with diffuse or nodular thyroid enlargement-and solitary thyroid nodules at the Goa Medical College Hospitals, Bambolim Goa, India, from January 1986 to June 1993, were reviewed. Two thousand four biopsies were performed on 1,992 patients, with 12 patients undergoing repent FNA biopsy at different times dire to an inconclusive primary result. These repeat biopsies were also inconclusive and were excluded from the series, leaving 1,992 cases. Two hundred thirty-eight of these 1,992 cases underwent surgery, either excision of the nodule or some form of thyroidectomy for a cytologically suspicious diagnosis, compression symptoms or cosmetic reasons, and a cytohistopathologic correlation was established in these cases. Twenty-five of the 238 cases that had inadequate cytologic findings were excluded, and the accuracy was studied in the remaining 213 cases. RESULTS: The results of FNA classified 1,557 (78.16%) of these cases as benign, 151 (7.58%) as suspicious, 30 (1.51%) as malignant and 254 (12.75%) as unsatisfactory. Cytohistopathologic correlation runs established in 238 cases, which were operated on. Nine (5.5%) of 163 cases with an FNA diagnosis of benign, 10 (26.3%) of 38 cases with an FNA diagnosis of suspicious and 11 (91.67%) of 12 cases with an FNA diagnosis of malignant were histologically malignant. CONCLUSION: FNA biopsy of the thyroid can be used effectively as the initial modality in the evaluation of thyroid lesions, both nodular and diffuse. It is very useful in detecting neoplastic foci in multinodular goiter and also in evaluating solitary thyroid nodules.