Application of the Bethesda system for reporting thyroid cytopathology for classification of thyroid nodules: A clinical and cytopathological characteristics in Bhutanese population

Abstract

Introduction:The existence of baseline data on the spectrum of thyroid nodules in Bhutanese patients is unknown. Fine-needle aspiration cytology (FNAC) is regarded as the gold standard diagnostic test for pre-op assessment of thyroid lesions. Materials and Methods:We conducted a retrospective study, involving 765 patients who underwent FNAC of the thyroid gland, at Jigme Dorji Wangchuck National Referral Hospital, Thimphu, between January-2018 to December-2020. We aimed to assess the cytomorphological spectrum of thyroid nodules, classify them as per The Bethesda system for reporting thyroid cytopathology (TBSRTC), assess risk of malignancy (ROM), and evaluate the accuracy of FNAC in diagnosing thyroid malignancy.Results: Colloid nodule (37.4%) and papillary thyroid carcinoma (4.2%) constituted the majority of benign and malignant cytological diagnoses, respectively. According to TBSRTC, majority of the cases (82.0%) fell under the Bethesda II category.Bethesda III was the least common (1.4%) category. As compared to histopathological diagnosis; the sensitivity, specificity, positive and the negative predictive values of FNAC in diagnosing thyroid malignancy were 90.0%, 93.3%, 93.10%, and 90.32% respectively. The ROM increased concurrently with the grade of the Bethesda category and was more or less close to the ROM reference range, published in the TBSRTC. Conclusion:Benign thyroid nodules (82.0%) constituted a majority of thyroid nodules in Bhutanese patients. FNAC was found to be reliable in detecting thyroid malignancy. From the literature, TBSRTC was found to be a more convenient method for reporting thyroid cytology. Henceforth, as most institutes, we plan to implement TBSRTC for reporting thyroid cytopathology. K E Y W O R D Sfine-needle aspiration cytology, the Bethesda system, thyroid malignancy, thyroid nodule | INTRODUCTIONThyroid gland is the largest endocrine organ in the human body that is affected by both neoplastic and non-neoplastic diseases, leading to diffuse and/or nodular enlargement. Depending on the screening approaches, the prevalence of thyroid nodules ranges from 20% to 60%. 1,2 Although non-neoplastic lesions are relatively more common, thyroid malignancy is the most serious clinical condition behind a

Assessment of thyroid lesions using fine-needle aspiration cytology in accordance with The Bethesda System and its histopathological correlation - A prospective study.

“…The Findings were comparable to the study done by Choden et al [6] In the present study, categorization of thyroid lesions based on the Bethesda system showed category 1 lesions-5.5%, category II lesions-85%, category III -2.5%, category III-3.5%, category IV-1%, Category V-4% and category VI-6%. These findings are comparable to the information gathered from earlier investigations done by Kanukuntla et al 15 and Swati et al There were three discordant cases in the present study.…”

“…Five to six groups of well-preserved follicular cells, each having ten or more cells, should be present in an acceptable thyroid cytological smear. 2 This study showed an adequacy rate of 94.5%, which is found to be comparable with the studies done by Choden et al 6 and Nandedkar et al 2,6 In the present study, 87.57 % were female and 12.43% were male patients with a male-to-female ratio of 1:7. These results were comparable with Handa et al The cyto-histopathological correlation done on 33 patients showed high specificity in identifying malignant lesions, high negative predictive value, positive predictive value, and diagnostic accuracy, and a relatively low sensitivity as compared to previous studies.…”

A Comparative Analysis of Thyroid Cytology Classification Systems: Bethesda System Versus Frcpath, Australian, Japanese, and Italian Approaches in the Indian Context

“…Thyroid cytology classification systems play a crucial role in the accurate diagnosis and management of thyroid nodules, thereby influencing patient care outcomes [5,6]. In this study, a comparative analysis is conducted for five widely used classification systems: TBS, FRCPath, Australian, Japanese, and Italian systems, within the context of the Indian health-care system.…”