Expression of MMP-2, MMP-9 and MMP-11 in dermatofibroma and dermatofibrosarcoma protuberans

Dermatofibroma (DF) and dermatofibrosarcoma protuberans (DFSP) are the spindle cell mesenchymal neoplasms of the dermis and subcutis. Their histogenesis still remains uncertain and controversial. Traditionally, CD34 and factor XIIIa or other markers have been widely used to distinguish these two diseases. However, the results of these markers reveal overlapping and they lack specificity. Formalin-fixed, paraffin-embedded blocks were collected from the biopsied cases in Kaohsiung Medical University Hospital in Taiwan between 2004 and 2006. This study included 19 cases of DF and 17 cases of DFSP. Immunohistochemical analysis using antibodies CD34, matrix metalloproteinases (MMP)-2, MMP-9, and MMP-11 was performed. We found that the expression of CD34, MMP-2 and MMP-11 shows significant statistical differences in Immunohistochemistry (IHC) study positive or negative reactivity (positive of CD34 in DFSP and positive of MMP-2 and MMP-11 in DF; p=0.03, p<0.001, and p<0.001, respectively) between DF and DFSP. The result for expression of MMP-9 reveals no differences. The results indicate that the pathogenesis of DF and DFSP are affected by different expressions of extracellular matrix proteins. Metalloproteinases may play a direct role in these two diseases. Since no single marker can completely distinguish DF from DFSP, a combination of more than two or three stains may elevate the accuracy of diagnosis.