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.
Nair
Vidhya
V
Department of Pathology, University Health Network, Toronto General Hospital, 200 Elizabeth Street, 11th Floor, Eaton Wing, Room 312, Toronto, M5G 2C4, Ontario, Canada. vidhya.nair@utoronto.ca
Weinreb
Ilan
I
MacNeil
Niki
N
Szollosi
Zoltan
Z
Chetty
Runjan
R
Ghazarian
Danny
D
D000328:Adult; D018952:Antigens, CD34 / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism*; D003937:Diagnosis, Differential; D026122:Factor XIIIa / Q000378:metabolism; D005260:Female; D018219:Histiocytoma, Benign Fibrous / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D009418:S100 Proteins / Q000378:metabolism; D012878:Skin Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D014178:Translocation, Genetic / Q000235:genetics
D018952:Antigens, CD34; D014408:Biomarkers, Tumor; D009418:S100 Proteins; D026122:Factor XIIIa