Immunohistochemical Detection of BRAFV600E in Cutaneous Melanocytic Neoplasms in a Cohort of Egyptian Population

Nada M. Yakout; Dina M Abdallah; Doaa A Abdelmonsif; Hassan Mahmoud  Kholosy; Omayma Elsakka

doi:10.31557/apjcc.2022.7.4.747-751

Authors

Nada M. Yakout Pathology Department, Faculty of Medicine, Alexandria University, Egypt.
Dina M Abdallah Pathology Department, Faculty of Medicine, Alexandria University, Egypt.
Doaa A Abdelmonsif Medical Biochemistry Department, Genomics Research Lab, Faculty of Medicine, Alexandria University, Egypt.
Hassan Mahmoud Kholosy Department of Plastic Surgery, Faculty of Medicine, Alexandria University, Egypt.
Omayma Elsakka Pathology Department, Faculty of Medicine, Alexandria University, Egypt.

DOI:

https://doi.org/10.31557/apjcc.2022.7.4.747-751

Keywords:

BRAFV600E, melanoma, nevi, bleaching, egyptian

Abstract

Objective: Melanocytic neoplasia shows different pathways that have been implicated in tumorigenesis. One of the key genes involved in the BRAFV600E gene, can be detected through DNA-based or protein-based tests including immunohistochemistry (IHC). To check its reproducibility, this study was conducted to evaluate BRAFV600E IHC by different observers in a range of melanocytic neoplasms.
Methods: The present study was performed to evaluate immunohistochemical staining (IHC) using the RM-08 to detect BRAF V600E in 50 formalin-fixed paraffin-embedded (FFPE) blocks of different melanocytic neoplasms after bleaching using Tris-HCL buffer. IHC was considered positive when more than 90% of tumour cells showed cytoplasmic staining. IHC assessment by a team of two pathologists and a third pathologist to check the interobserver variability. IHC scores were compared among nevi and melanoma.
Results: IHC evaluation revealed good agreement by different observers (ĸ-coefficient=0.691, p=0.00). BRAFV600E showed a statistically significant difference between nevi and melanoma.
Conclusions: These findings suggest that BRAFV600E IHC assessment shows good reproducibility among pathologists, however, more strict criteria should be adopted in interpretation, especially in bleached samples.