Bethesda Made It Clearer: A Review of 542 Patients in a Single Institution

Abstract

Background: It is essential to interpret fine needle aspiration biopsy (FNAB) material correctly to create a common language among pathologists and surgeons, leading to a uniform approach to thyroid nodule management. We aimed to compare FNAB reports of patients at our institution who were treated with total thyroidectomy, before and after the Bethesda classification system.

Patients and methods: Patients who underwent total thyroidectomy for thyroid nodules are reviewed. 226 patients who underwent total thyroidectomy before the Bethesda era (2006-2009) were classified as Group-I, and 316 patients in whom total thyroidectomy was performed after the Bethesda classification system was introduced (2010-2014) were classified as Group-II.

Results: Before Bethesda, 'nondiagnostic' or 'benign' lesions were reported in 16.4 and 45% of patients, respectively, which then significantly decreased to 4.7 and 32.9% as the Bethesda classification criteria came into use. In Group-II, the actual malignancy rates were 13.3, 2.8, 7.3, 15.5, 85.4, and 96.5% for Bethesda I, II, III, IV, V, and VI, respectively.

Conclusion: Our experience confirms that the Bethesda classification system leads to a significant reduction in lesions that used to be reported as 'benign' without compromising the actual rates of malignancy. It ensures better classification of so-called suspicious lesions, and allows for more accurate predictions of suspicious or malignant lesions.

Keywords: Bethesda; Fine needle aspiration biopsy; Thyroid cancer; Total thyroidectomy.