Immunohistochemical Dissection of Cystic Panfolliculoma Focusing on the Expression of Multiple Hair Follicle Lineage Markers with an Insight into the Pathogenesis

The study focused on cystic panfolliculoma (CPF), a rare benign tumor with differentiation towards all components of the hair follicle, and its histological similarity to trichofolliculoma. Researchers used a panel of antibodies to detect various cytokeratins and hair-hard keratin within the lesion, supporting the diagnosis of CPF. Immunohistopathological examinations revealed distinct spatial distribution patterns of tumor cells with specific hair follicle differentiation markers. The study suggested that epithelial-mesenchymal interactions (EMIs) play a role in CPF pathogenesis, with fibroblastic dermal cells preferentially located near certain epithelial structures. These interactions might explain the immature hair follicle differentiation in CPF, contrasting with the mature structures seen in trichofolliculoma.