Abstract
PRAME (PReferentially expressed Antigen in MElanoma) is an antigen that was isolated from autologous T-cells in a melanoma patient PRAME was identified as a melanoma-associated gene by Clarke et. al which was subsequently confirmed by Mitsui et. al. The utility of PRAME IHC has been under recent study with investigators attempting to quantify the staining pattern of various benign and malignant melanocytic tumors. All cases of melanoma in situ with features of concomitant compound or junctional dysplastic nevi were retrieved from the archives from calendar year 2013a total of 81 cases. There were 17 cases of melanoma in situ with compound dysplastic nevi. Cases were reviewed by three dermatopathologists with agreement on diagnosis. Five micrometer thick tissue sections were cut from formalin-fixed and paraffin-embedded tissue blocks. Serial sections will be stained for H&E, PRAME (MAb ERP20330; Abcam, #129650), Sox10 (MAb BP0104; StatLab, #QHD-MM166-2x-15), and S100 (MAb 4C4.9; StatLab, #QHD-MM144). Results will be quantified digitally with either the cell population of interest (melanoma in-situ or compound dysplastic nevus) staining positive or negative for PRAME with statistical analysis presented on the poster, and will be completed by a dermatopathologist blinded to the study. Our hypothesis is that the melanoma in-situ component of the sections will stain positive with PRAME, while the background compound dysplastic nevus will not stain with PRAME. Note to selection committee: PRAME IHC has been completed on the mentioned cases and supports the hypothesis; however, results will be published when all data from the study is completed. SOX10 and S100 immunohistochemical staining and correlation with the PRAME sections and subsequent statistical analysis comprises the remainder of this studythis will be completed in advance of the ASDP 2021 meeting.
Financial Disclosure:
No current or relevant financial relationships exist.