Abstract

A 19-year-old Korean man presented with a tender, erythematous atrophic plaque approximately 3.2 x 2.7 cm in size over the left subclavicular area. The lesion had commenced 9 years prior as a flat macule and grew over that time with repetitive trauma from jujitsu. He initially refused a skin biopsy because he had been previously diagnosed with a biopsy-proven benign disease at another hospital. Thus, we suspected trauma-induced lipodystrophy and performed a comprehensive evaluation. The routine laboratory test results were normal. Thoracic magnetic resonance imaging revealed a well-demarcated mass approximately 4.6 x 5.3 x 0.7 cm in size with adjacent subcutaneous atrophy. We again recommended a skin biopsy; this time, he agreed. Histopathological examination revealed a local infiltrative tumor composed of monomorphic spindle cells with a diffuse storiform pattern that extended to the subcutaneous fibrous septa. Mitotic figures and dysplasia were almost absent. Immunohistochemistry revealed that the spindle cells were diffusely positive for CD34 but not for S-100, SMA, or CD68. He was thus diagnosed with atrophic dermatofibrosarcoma protuberans (DFSP). Atrophic DFSP is a rare variant of DFSP, but both exhibit similar biological behaviors and histopathological features. DFSP pathogenesis reflects the presence of the COL1A1-PDGBF fusion gene, which causes autocrine activation of the platelet-derived growth factor ?-chain and thus, malignant transformation. Diagnosis can be considerably delayed; DFSP clinically resembles morphea, atrophoderma, anetoderma, lipodystrophy, sclerodermic basal cell carcinoma, and a hemangioma. Unlike classic DFSP, the non-elevated variant exhibits a female predilection and is associated with earlier onset and a higher incidence in children. Herein, we report a rare case of atrophic DFSP; we hope that physicians find our note of assistance.

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