A unique biphasic variant of cutaneous fibrous histiocytoma with a storiform pattern and intralesional pigmented melanocytes: "storiform melano-fibrous histiocytoma".

Dermatofibromas (cutaneous fibrous histiocytomas) are common cutaneous neoplasms of mesenchymal origin. They are often associated with epidermal hyperplasia and increased basal layer pigmentation. There have been reports of a spectrum of melanocytic lesions associated with dermatofibromas ranging from junctional nevi to malignant melanomas, some of which may be coincidentally associated. We report a case of a long-standing storiform fibrohistiocytic lesion devoid of cytological atypia, lacking extension into subcutaneous fat, not demonstrating the t(17;22) DFSP translocation yet showing diffuse and strong CD34 immunoreactivity and containing pigmented spindle shaped melanocytic cells admixed with the fibrohistiocytic component. This case raises a nosological debate given the histological, immunophenotypic and cytogenetic findings.