Correlation study of thyroid nodule cytopathology and histopathology at two institutions in Jordan.

Background: Fine-needle aspiration (FNA) plays a fundamental role in determining the appropriate management for patients presenting with thyroid nodules.

Aims: The aims of this study are to evaluate thyroid FNA test performance parameters through a cytohistological correlation.

Materials and Methods: A retrospective analysis of all thyroid FNAs received over a period of 18 months was carried out. The findings were compared to their subsequent definite diagnoses on surgical specimens as well as to their follow-up repeat FNA results. A total of 499 thyroid FNAs were collected and reviewed against The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). The percentage of each diagnostic category was calculated, and the implied risk of malignancy was determined by comparing the cytology results to their definite diagnoses obtained on the resection specimens. Analytical procedures were performed using Microsoft Excel.

Results: Out of 499 thyroid FNAs, a benign interpretation was found in 273 patients (54.7%), atypia of undetermined significance in 81 (16.2%), follicular neoplasm in 20 (4%), suspicious for malignancy in 36 (7.2%), malignant in 32 (6.4%) and were nondiagnostic in 57 patients (11.4%). Only 101 patients (20.2%) underwent surgical resection and 47 (9.4%) underwent a follow-up FNA. After cytohistological correlation, FNA test performance, calculated by excluding the inadequate and undetermined categories revealed test sensitivity, specificity, and diagnostic accuracy of 95.6%, 54.8%, and 78.9%, respectively. The positive predictive value was 75.4%, and the negative predictive value was 89.5%.

Conclusions: Our results are comparable to those previously published figures. The rate of atypia of undetermined significance/follicular lesion of undetermined significance is higher than what is currently recommended in TBSRTC.