RELATIONSHIP OF MALIGNANCY IN THYROID NODULES WITH REPEAT BETHESDA III CLASSIFICATION ON FINE NEEDLE ASPIRATION BIOPSY

Abstract

OBJECTIVES
There is no consensus regarding treatment options available for patients with repeat Bethesda III Classification. This may cause anxiety regarding additional procedures and possible delay in definitive diagnosis and management. This study aimed to evaluate the risk of malignancy as well as the predictors of malignancy for repeat Bethesda III nodules on fine needle aspiration biopsy (FNAB).

METHODOLOGY
A single center, ambispective cross-sectional study of adult patients with thyroid nodules who underwent both initial and repeat fine needle aspiration biopsy at the Diabetes, Thyroid and Endocrine Center of St. Luke’s Medical Center Quezon City was conducted. The Thyroid Registry was utilized to collect each patient’s demographic and clinical characteristics, ultrasonographic features of thyroid nodules, and cytopathologic and histopathologic results. Subclassification of atypia/follicular lesion of undetermined significance (AUS/FLUS) were retrieved from cytopathology reports using the electronic Healthcare- Results Management System of the same institution.

RESULTS
A total of 59 adult patients with thyroid nodules were included. Thirty-eight patients were malignant based on histopathology, having an incidence of 64.41% (95% CI: 51.22-75.72%). There were no significant differences in clinical, ultrasonographic and cytopathologic features of malignancy between benign and malignant nodules.

CONCLUSION
A second FNAB result of AUS/FLUS carries a 64% risk of malignancy. This suggests an elevated risk of malignancy compared with a single FNAB result of Bethesda III (5- 15%). This supports surgical intervention (lobectomy/thyroidectomy) as a reasonable option after a second Bethesda III classification on FNAB.