[534] Array Comparative Genomic Hybridization (aCGH) on Dermatofibromas (DF): Additional Evidence To Support a Neoplastic Process.

Wei Zhang, Sandra S Osswald, Shelly R Gunn, Martin P Fernandez. University of Texas Health Science Center, San Antonio; Combimatrix Molecular Diagnostics, Irvine, CA

Background: There has been considerable debate over the pathogenesis of DF. Some believe they represent a fibrosing inflammatory process, while others maintain they are neoplastic in nature. Reports of metastasizing DF, and the recognition of DF variants with a tendency to recur have fueled this debate, and catapulted it into the realm of clinical relevance.
Design: A total of 10 cases were studied: 8 DF (6 ordinary DF, 1 aneurysmal DF and 1 cellular DF); 1 angiomatoid fibrous histiocytoma and 1 hypertrophic scar. All cases were formalin-fixed paraffin-embedded. aCGH analysis of the lesional genome was performed using a 3039 probe whole genome bacterial artificial chromosome (BAC) microarray. The presence of copy number changes was correlated with additional clinico-pathologic findings, such as involvement of the subcutaneous tissue.
Results: Four cases showed copy number changes: The cellular DF showed the most obvious abnormalities with loss of large portions of 5q and 6q. Three ordinary DF showed other genomic abnormalities: One showed monosomy 19, a second showed a 19p loss, and a third showed a 19p gain. No obvious copy number changes were seen in any of the other four DF, in the angiomatioid fibrous histiocytoma, or in the hypertrophic scar. Of the eight DF studied, four showed focal involvement of the subcutaneous tissue and the other four were limited to the dermis. The four cases with the above described genomic abnormalities coincided with those showing focal involvement of the subcutaneous tissue.
Conclusions: The finding of copy number changes in a proportion of the cases studied suggests that DF, at least in some instances, may indeed represent a neoplastic process. The presence of genomic abnormalities in the subset of DF showing focal extension into the subcutaneous tissue, including the cellular DF, provides further evidence to support this hypothesis. Complete excision of dermatofibromas should be considered in those cases involving the subcutaneous tissue.
Category: Dermatopathology

Wednesday, March 2, 2011 1:00 PM

Poster Session VI # 120, Wednesday Afternoon


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