The Bethesda System for Reporting Thyroid Cytopathology: A Cytohistological Study

Abstract

Introduction. The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) is a significant step to standardize the reporting of thyroid fine needle aspiration (FNA). It has high predictive value, reproducibility, and improved clinical significance. Aim. The study was aimed to evaluate the diagnostic utility and reproducibility of “TBSRTC” at our institute. Methods and Material. The study included 646 thyroid FNAs which were reviewed by three pathologists and classified according to TBSRTC. Cytohistological correlation was done for 100 cases with surgical follow-up and the sensitivity, specificity, positive predictive value, negative predictive value, diagnostic accuracy, and risk of malignancy (ROM) were calculated. The interobserver variation among three pathologists was also assessed. Results. The distribution of cases in various TBSRTC categories is as follows: I—nondiagnostic 13.8%, II—benign 75.9%, III—atypia of undetermined significance (AUS)/follicular lesion of undetermined significance (FLUS) 1.2%, IV—follicular neoplasm (FN)/suspicious for follicular neoplasm (SFN) 3.7%, V—suspicious for malignancy (SM) 2.6%, and VI—malignant 2.8%. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy are 72.4%, 94.3%, 84%, 89.2%, and 87.9%, respectively. The ROM of various TBSRTC categories were II—8.5%; III—66.7%; IV—63.6%; and V and VI—100%. Cohen’s Weighted Kappa score was 0.99 which indicates almost perfect agreement among the three pathologists. Conclusions. Our study substantiates greater reproducibility among pathologists using TBSRTC to arrive at a precise diagnosis with an added advantage of predicting the risk of malignancy which enables the clinician to plan for follow-up or surgery and also the extent of surgery.

The combination of ACR‐Thyroid Imaging Reporting and Data system and The Bethesda System for Reporting Thyroid Cytopathology in the evaluation of thyroid nodules—An institutional experience

“…The foremost advantage of TBSRTC is maintaining uniformity in the interpretation of thyroid FNA and guiding the clinicians to plan appropriate therapy. The preoperative diagnosis of thyroid lesions in the present study using TBSRTC was comparable with other studies as summarised in Table 5 10‐14 . The ND/UNS category still challenges accurate diagnosis.…”

Tiroid Nodüllerinin Değerlendirilmesinde Bethesda Sistemi ve İnce İğne Aspirasyon Biopsisinin Yeri

“…The vast majority of false-negative results is insufficient sampling, and the reason for this is that PTMCs (2,3,(7)(8)(9)(10)(11)(12)(13)(14). The current study, PTMCs were the most common cause of false negativity in line with the literature (2,3,(7)(8)(9)(10)(11)(12)(13)(14).…”

“…This distinction is not so clear especially in the Bethesda classification, which has 6 diagnostic categories and is used in cytological evaluation. The reason why the sensitivity and specificity are in such a wide range in the literature is due to the difficulty and differences in identifying benign and malignant groups in studies (2,3,(7)(8)(9)(10)(11)(12)(13)(14). In our study, as in most of the studies, the FN/SFN category was accepted in the malignant group in addition to the MC category.…”

“…False positivity is generally below 5% in publications, but false negativity ranges varies between 0-16% (16,17). However, when we look at the current publications (Table 5), the false positivity is between 3.5-11.90, while the false negativity is 2.3-42.11 (2,3,(7)(8)(9)(10)(11)(12)(13)(14). The fact that the publications made in the last 10 years have higher results than previous publications has been linked to the increase in the number of thyroidectomy operations performed (18).…”

“…When we look at the current literature, the highest result is 15.5 and is belonged to Muratlı et al (7). In the literature, the cytologicalhistopathological incompatibility rate is quite high when it comes to follicular lesions (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). Fine needle aspiration biopsy is particularly sensitive in detecting papillary, medullary, anaplastic carcinoma, poorly dif-ferentiated follicular and insular carcinoma, while the sensitivity decreases and the false positivity increases in lesions such as adenomatous nodules, FA, well-differentiated FC, HT and noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) which have similar cytological features (7).…”