Immunohistochemical Expression of HBME-1 in a Spectrum of Thyroid Neoplasms

Introduction: Thyroid neoplasms are the most common malignancy of the endocrine system, representing 3.8 of new cancer cases, and it is the ninth most common cancer overall. The immuno-histochemical marker Hector Battifora Mesotheilial-1 (HBME-1) is a monoclonal antibody that now finds its diagnostic utility as a positive marker for well-differentiated thyroid carcinomas. The aim was to study the expression of HBME-1 and to differentiate between malignant and non-malignant lesions by demonstrating their usefulness in the categorisation of thyroid neoplasms. Methods: A prospective study was conducted at a tertiary care centre from August 2022 to May 2023, comprising 25 cases. All thyroidectomy specimens were included. They were subjected to histopathological examination using routine haematoxylin and eosin stain, and further confirmation was made by immuno-histochemical staining for HBME-1. Results: There were a total of 25 cases consisting of 23 (92) females and two (8) males. The maximum number of cases was seen in the age group of 21-30 years (27), followed by 31-40 years (24) and 41-50 years (24). The most common thyroid neoplasm noted was the follicular variant of papillary thyroid carcinoma (40) with HBME-1 being strongly positive for papillary thyroid carcinoma and its variants compared to other tumour sub-types, where it shows diffuse and focal expression. Conclusion: HBME-1, due to its high sensitivity, can be significantly used as a marker for identification and differentiation, particularly papillary thyroid carcinoma. However, using a panel of markers comprising Galectin-3 and Ck-19 along with HBME-1 increases the accuracy and specificity for the correct diagnosis of thyroid neoplasms. Keywords: HBME-1, malignancy, thyroid, thyroid neoplasm