Diagnostic Accuracy of Fine Needle Aspiration Cytology in Thyroid Lesions: Analysis of Histologically Confirmed 153 Cases

Park, Kyeong Mee; Ko, Ill Hyang

Abstract

This is a retrospective review of fine-needle aspiration cytology(FNAC) smears of 153 cases of thyroid disease performed during August 1989 to July 1995, which were confirmed histologically following surgical operations. FNAC results showed 63 cases(41.2%) of adenomatous goiter, 45 cases(29.4%) of papillary carcinoma, 29 cases(19.0%) of follicular neoplasm, 4 cases(2.6%) of follicular variant of papillary carcinoma, 4 cases(2.6%) of Hashimoto's thyroiditis, 4 cases(2.6%) of Hurthle cell neoplasm, 2 cases(1.3%) of medullary carcinoma and one case(O.7%) each of subacute thyroiditis and of anaplastic carcinoma. The overall accuracy of cytological diagnosis was 83.7%. These data strongly suggest thyroid FNAC is a reliable preoperative diagnostic tool, but FNAC has been less valuable in the diagnosis of follicular lesions than any other disease of the thyroid. Adenomatous goiter was not infrequently interpreted as follicular neoplasia that requires surgery for diagnostic .conformation and vice versa. The following findings are considered to be compatible with follicular neoplasm: 1) microfolticles, 2) nuclear grooving, 3) irregularity of nuclear membrane, and 4) irregular arrangement or crowding of follicular cells in groups. The FNAC criteria of adenomatous goiter are as follows: 1) atrophic follicular cells, 2) presence of macrophages, 3) abundant colloid, and 4) large follicles. It is recommended that aspiration of thyroid lesions in order to analyse with critical clinico pathological approach and surgery is considered only for nodules that are clinically suspicious or unresponsive to hormone therapy or when a diagnosis of follicular neoplasm is made.