Use of the immunohistochemical marker HBME-1 to optimize the diagnosis of follicular carcinomas

Abstract

Background. In clinical practice, there are often patients with a diagnosis of benign follicular adenoma (FA) and follicular tumor with an uncertain malignant potential, whose diagnoses must be changed to malignant processes due to relapse or metastasis observed over time. The purpose of the study was to optimize the differential diagnosis of FA and follicular thyroid carcinoma (FTC) using the immunohistochemical (IHC) marker HBME-1 on the histological material of patients who were operated for nodular goiter with a cytological conclusion corresponding to the Bethesda categories III–V. Materials and methods. One hundred and twenty-four patients underwent surgery for follicular nodular neoplasms with a cytological conclusion according to Bethesda Gray zone and had a histological diagnosis of FTC in 23 ca­ses (18.55 %) and FA in 101 cases (81.45 %). IHC analysis was performed using mouse monoclonal antibodies against human HBME-1 (Bio SB, USA). Evaluation criteria corresponded to the strength of staining (from 0 to 3). Results. According to the intensity of IHC staining, there was an increase in the diagnosis of FTC (p < 0.05): 0 — 0 %, 1 — 12.7 %, 2 — 25 %, 3 — 36.4 %. Histopathological findings were reexamined for FA that had the strongest staining reaction: in 3 (2.97 %) cases, the diagnosis was changed to FTC. Accor­dingly, the total number of detected FTC increased to 26 (20.96 %). These cases showed a good positive result regarding IHC study with HMBE-1 on FA preparations for a differential diagnosis between FA and FTC. Conclusions. HBME-1 can serve as an IHC marker for the differential diagnosis of FA and FTC in cases considered as FA, as after the study, the diagnosis was changed to FTC in 2.97 % of patients.

Keywords

• thyroid gland
• follicular carcinoma
• follicular tumor with an uncertain malignant potential
• hbme-1