Original articles
Identifying thyroid follicular proliferations that need lobectomy; value of the Bethesda category 4
Authors:
A. Kankanamge,
University of Ruhuna, Galle, LK
About A.
Department of Pathology, Faculty of Medicine
T. G. Liyanage ,
University of Ruhuna, Galle, LK
About T. G.
Department of Pathology, Faculty of Medicine
L. K. B. Mudduwa
University of Ruhuna, Galle, LK
About L. K. B.
Department of Pathology, Faculty of Medicine
Abstract
Introduction: Thyroid follicular proliferations (TFPs) identified on fine needle aspiration cytology can be either follicular lesions of undetermined significance; Bethesda category 3 or follicular neoplasms and lesions suspicious for a follicular neoplasm; Bethesda category 4. The purpose of categorizing to Bethesda category 4 is to identify a thyroid nodule that might be a follicular carcinoma and triage it for thyroid lobectomy. This study was designed to determine the predictive value of categorizing TFPs to Bethesda category 4 in deciding on lobectomy for cytologically identified TFPs.
Methods: This retrospective study included all patients with TFPs identified on cytology, and had a subsequent histological diagnosis, at our unit, over a period of two years. TFPs were categorized into either Bethesda category 3 or 4 on cytology, according to the Bethesda system. Sensitivity, specificity and positive (PPV) and negative predictive values (NPV) for Bethesda category 4 in identifying neoplastic TFPs and implied risk of malignancy for Bethesda category 3 and 4 were calculated taking histopathology as the gold standard. A total of 52 TFPs (Bethesda category 3; n = 39, Bethesda category 4; n = 13) were included. Subsequent histology has confirmed 18 neoplastic and 34 non-neoplastic TFPs. Sensitivity and specificity of Bethesda category 4 in identifying neoplastic TFPs were 66.66% and 97.05% respectively. PPV and NPV of Bethesda category 4 were 92.3% and 84.6% respectively. Implied risk of malignancy for Bethesda category 3 and 4 were 5.12% and 15.38% respectively.
Conclusions: Bethesda category 4 predicts the TFPs that need thyroid lobectomy to triage for follicular carcinoma. The Bethesda category 3 and 4 carry an implied risk of malignancy comparable to the expected values given in Bethesda system.
How to Cite:
Kankanamge, A., Liyanage, T.G. and Mudduwa, L.K.B., 2021. Identifying thyroid follicular proliferations that need lobectomy; value of the Bethesda category 4. Galle Medical Journal, 26(2), pp.68–73. DOI: http://doi.org/10.4038/gmj.v26i2.8088
Published on
14 Aug 2021.
Peer Reviewed
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