The Combined Utility of HBME-1 and Galectin-3 Immunohistochemistry and BRAF V600E Mutations in the Diagnosis of Papillary Thyroid Carcinoma

Immunohistochemistry in the pathologic diagnosis and management of thyroid neoplasms

The use of immunohistochemistry cannot be underestimated in the everyday practice of thyroid pathology. It has evolved over the years beyond the traditional confirmation of thyroid origin to molecular profiling and the prediction of clinical behavior. In addition, immunohistochemistry has served to implement changes in the current thyroid tumor classification scheme. It is prudent to perform a panel of immunostains, and the immunoprofile should be interpreted in light of the cytologic and architectural features. Immunohistochemistry can also be easily performed in the limited cellularity specimen preparation generated from thyroid fine-needle aspiration and core biopsy; however, it will require laboratory validation of immunostains specific to these preparations to avoid diagnostic pitfalls. This review discusses the application of immunohistochemistry in thyroid pathology with a focus on limited cellularity preparations.

Scoring System and Diagnosis of Papillary Thyroid Carcinoma Using Human Bone Marrow Endothelium Marker-1, Cytokeratin 19, and Galectin-3

Background

The increasing incidence of papillary thyroid carcinoma (PTC) and the inadequacy of routine histologic examination in its diagnosis necessitate the application of ancillary studies like immunohistochemistry. This research aimed to investigate the scoring system and diagnosis of PTC with cytokeratin 19 (CK19), human bone marrow endothelium marker-1 (HBME-1), and galectin-3.

Methods

This experimental laboratory study was performed at Babol University of Medical Sciences, Mazandaran, Iran from April 2017 to March 2019. Neoplastic and nonneoplastic tissue samples of 100 cases with a diagnosis of PTC were selected by convenience sampling. CK19, HBME-1, and galectin-3 immunohistochemistry markers were used on tissue samples. Analysis was performed using the t test and the chi-square test, as well as the receiver operator characteristic (ROC) curve (significance level P < 0.05).

Results

The CK19 staining was observed in all 100 (100%) non-neoplastic tissues, but HBME-1 and galectin-3 were positive in 36 (36%) and 14 (14%) of non-neoplastic tissues, respectively. The intensity scores of all the markers and their total had significantly different means in PTC and non-neoplastic tissues (P < 0.001). A significant difference was observed between the total score of each marker and the total score of their combination (P < 0.001). The combination of all 3 markers with an 11.5 0 cut-off for the total score showed the most sensitive (0.99) and specific (1.00) results.

Conclusion

Interpreting CK19, HBME-1, and galectin-3 with the aid of the proposed scoring system was fruitful. HBME-1 and galectin-3 can be used individually or in combination for the diagnosis of PTC.

Lights on HBME-1: the elusive biomarker in thyroid cancer pathology

Among the different ancillary immunohistochemical tools that pathologists may employ in thyroid nodules, the so-called Hector Battifora's 'MEsothelioma' 1 (HBME-1) staining is one of the most fascinating, since its real identity is currently unknown. In the present review, the different clinical applications of HBME-1 are analysed, with main emphasis on its role in thyroid pathology with overview on less impactful fields, such as haematopathology or mesothelial lesions. Different acceptable or good diagnostic performances were recorded for HBME-1 in thyroid pathology, being used in routine practice as one of the best tools to screen thyroid malignancy both in terms of sensitivity and specificity. From a speculative point of view, after many attempts to hunt the cryptic target antigen of this antibody, its identity still remains elusive. In this setting, the application of high-throughput technologies (mainly in situ proteomics) may be the exact route to improve the knowledge about the pathophysiology of HBME-1 and to finally unveil its true identity.