Does fine-needle aspiration cytology optimize the surgical management of thyroid disorders in endemic goiter region?

Aim: The aim of this study was to determine the diagnostic value of fine-needle aspiration cytology (FNAC) before thyroidectomy in an endemic goiter region.

Methods: One hundred patients with preoperative FNAC of thyroid nodules who underwent thyroidectomy were recruited. FNAC were classified into five groups. 0, no thyroid cells; 1, normal thyroid cells; 2, degenerative thyroid cells without evidence of malignacy; 3, follicular or oncocytary neoplasia; and 4, malignant thyroid cells. FNAC was compared with postoperative histopathological diagnoses.

Results: Only 76% of the FNAC allowed an adequate cytological examination. In 15 patients (15%), carcinomas were found in the postoperative histopathological diagnosis (including four follicular carcinomas). In the 48 patients of FNAC groups 3 and 4, nine carcinomas (18.7%) were found (including four follicular carcinomas). In the 28 patients of groups 1 and 2, there was only one papillary carcinoma (3.5%). In the 24 patients of group 0, there were two papillary, two follicular, and one anaplastic carcinomas (total of 20.8%). The sensitivity, specificity, and likelihood ratio (LR) of the FNAC for benign nodules were 90%, 40.9%, 0.24, respectively. The LR for malignant nodules was 13.2, and that for follicular neoplasia was 0.55.

Conclusions: Despite the high prevalence of carcinoma in an endemic goiter region, FNAC disappointed its diagnostic expectation. The lower specificity of FNAC may be caused by a higher prevalence of thyroid nodules in an endemic goiter region or by the absence of a specialized cytopathologist.