LAUSR

Digital papillary adenocarcinoma (DPA) is a rare sweat gland carcinoma arising on acral sites. The main differential diagnosis included tubular adenoma, hidradenoma, poroid hidradenoma, and mixed tumours, distinction between DPA and these mimickers being crucial for therapeutic management. Recently, HPV42 was identified as the main oncogenic driver of most DPA. Controversially, a few sweat gland tumour cases diagnosed as “DPA” but lacking the HPV42 genome and harbouring instead a BRAFV600E mutation, a genetic hallmark of tubular adenomas, have been recently described. Methylation analysis is a powerful tool for tumour classification systems. In this context, the aim of the present study is to evaluate the accuracy of methylation analysis for sweat gland tumour classification with special emphasis on the distinction between DPA and mimickers.