Abstract
A 66-year-old man had noticed a subcutaneous mass in the right chest about 5 to 6 years previously, but left it untreated. However, since the mass had begun to grow, about one and a half years ago, he consulted a local doctor, and was referred to our department in August 2003 for further evaluation. At initial examination revealed a large, well-demarcated, freely movable, subcutaneous mass, 17×10×7cm, which was palpable from the right anterior shoulder region to the anterior chest. On the outside of this mass, a cauliflower-like tumor with a 15×13×7cm ulcer was protruding. A wide excision extending up to 2cm from the tumor borders was performed, followed by shoulder skin flap repair and free skin grafting. Histological examination of the totally resected specimen revealed a dermatofibrosarcoma protuberans (DFSP) lesion in which relatively uniform, spindle-shaped cells grew in a cart-wheel pattern, and a fibrosarcomatous lesion showing a herringbone pattern. Histochemicalstaining showed that the DFSP lesion was strongly positive for CD34, but the fibrosarcomatous lesion was weakly stained. Cytogenetic examination identified the COL1A1-PDGFB fusion gene. These findings led to a diagnosis of dermatofibrosarcoma protuberans with fibrosarcomatous change. [Skin Cancer (Japan) 2005; 20: 268-272]
