SOX-10 and Melan-A Immunostaining in Areas of Focal Acantholytic Dyskeratosis and Epidermolytic Hyperkeratosis Within Dysplastic Nevi Biopsies: An Observational Study

This pilot examination provides evidence that areas of incidental FAD within dysplastic nevi biopsies demonstrate unexpected suprabasal layer staining with melanocytic markers. When dermatopathologists evaluate melanocytic neoplasms with melanocytic markers, it is possible the presence of incidental FAD could lead to over diagnosing pagetoid scatter within these lesions. This study is a proof of concept with mild to moderately dysplastic nevi that do not typically incur the use of melanocytic stains; however, the implication of this unexpected staining pattern would be important when using melanocytic markers on borderline melanocytic neoplasms that have incidental FAD. Close correlation with H&E is imperative to prevent misinterpretation in these cases.