Abstract

Dermatofibrosarcoma protuberans (DFSP) is a rare cutaneous tumor with potential for locally aggressive and recurrent behavior. The majority of DFSPs contain a t(17;22) translocation which leads to constitutive activation of the platelet-derived growth factor B chain (PDGFB) receptor. Histologically, DFSP is characterized by spindled cells arranged in a storiform pattern. The tumor stains diffusely for CD34. Rare histologic variants of DFSP have been described, including one with prominent verocay bodies. A 36-year-old man presented to the dermatology clinic for evaluation of a lesion on the left hip that had been present for about 2.5 years. Physical exam of the left hip revealed a 3.8x3.4 cm mobile, skin colored, bilobulated subcutaneous nodule. The patient underwent excisional biopsy which revealed a dermal-based neoplasm formed by elongated, delicate spindle cells. In some areas, the cells assumed a storiform pattern and in others they were arranged in palisaded arrays resembling verocay bodies. Immunohistochemical analysis revealed expression of CD34, but was negative for S-100, CD31, Factor XIIIA, AE1/AE3, and desmin. Molecular studies confirmed a PDGFB rearrangement. The patient was diagnosed with DFSP and subsequently underwent Mohs surgery for definitive treatment of the tumor without complication. Only a few cases of DFSP with verocay bodies have been reported in the literature. Other rare histologic variants of DFSP include pigmented (Bednar), giant cell fibroblastoma, fibrosarcomatous, myxoid, myoid, atrophic, and others. Pigmented and giant cell fibroblastoma variants are more prevalent in skin of color and juvenile patients, respectively, while fibrosarcomatous variant is associated with an aggressive and potentially metastatic phenotype. As of yet there is no clear clinical significance of other histologic variants. Further studies will be required to understand the clinical significance, if any, of DFSP with verocay bodies.

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