AUTHOR=Salih R. , Ismail F. , Orchard G. E. 

TITLE=Double Immunohistochemical Labelling of PRAME and Melan A in Slow Mohs Biopsy Margin Assessment of Lentigo Maligna and Lentigo Maligna Melanoma

JOURNAL=British Journal of Biomedical Science

VOLUME=Volume 81 - 2024

YEAR=2024

URL=https://www.frontierspartnerships.org/journals/british-journal-of-biomedical-science/articles/10.3389/bjbs.2024.12319

DOI=10.3389/bjbs.2024.12319

ISSN=2474-0896

ABSTRACT=Lentigo maligna (LM) and lentigo maligna melanoma (LMM) are types of melanoma that commonly affect the head and neck regions of older patients. They are characterized by illdefined and potentially large pigmented lesions with inconspicuous borders, making it difficult to accurately determine surgical margins for complete removal.Morphological examination of surgical margins is the key form of determining successful treatment in LM/LMM and underpin the greater margin control provided through the Slow Mohs micrographic surgery (SMMS) approach. The applications of immunohistochemistry (IHC) markers such as Preferentially Expressed Antigen in Melanoma (PRAME) have been recently evaluated within the context of LM/LMM and margin assessment. This is based on the selectivity for PRAME staining in malignant melanocytic neoplasms , versus those that are benign, showing promise as an arbiter within difficult melanocytic investigations. For this study, PRAME is ustilised in a double labelling (DL) method, combined with Melan A, as a means to further maximize the clinical utility of PRAME in the assessment LM/LMM in SMMS. The results showed substantial agreement, 96.1%, between the novel DS and singlelabelling (SL) slides with respect to PRAME and Melan A across the 51 samples tested. The reported sensitivity of the benchmark PRAME SL was 91.3% within the SMMS specimens and 67.9% within the histologically confirmed positive margins. This study highlights the utility of PRAME IHC and by extension PRAME DL as an adjunctive tool in the assessment of melanocytic tumours within staged excision margins in SMMS samples.