Immunohistochemical Profiles of Dermatofibroma and Dermatofibrosarcoma Protuberans: A Scoping Review

This review summarizes the immunohistochemical profiles of dermatofibroma (DF) and dermatofibrosarcoma protuberans (DFSP) as reported by primary literature in the past 10 years. 63 studies were included in the review, with staining information for a total of 99 unique IHC markers reported. The most commonly reported stains were CD34, SMA, S100, and FXIIIa. Most studies applied IHC either to explore descriptive features of DF or DFSP or to determine their utility in diagnostic identification of the lesions. Importantly, summary data of percent positivity for key markers such as CD34 and FXIIIa highlights gaps in the existing diagnostic paradigm using these markers alone. A number of studies applied novel biomarkers that may hold promise for distinguishing DF and DFSP, namely WT1, Cx43, LSP-1, and PHH3, which demonstrated considerable expression differences between the 2 lesions. This review highlights the need for validation of existing and emerging IHC markers for the diagnosis of DF and DFSP.