2025 Volume 40 Issue 2 Pages 121-126
An 18－year－old female presented with a purplish nodule on her left thigh 1 year earlier. She underwent resection by her previous doctor and was diagnosed with dermatofibrosarcoma protuberans (DFSP). A 2 cm margin from the mass and the inferior floor with an intrinsic fascia were resected. Histopathologically, spindle－shaped cells proliferated irregularly in the dermis, creating a honeycomb－like appearance in the subcutaneous fat, and more than 80% of the tumor showed mucinous changes. Immunohistochemical staining was positive for CD34 and negative for factor ⅩⅢa. Therefore, the patient was diagnosed with myxoid DFSP. The incidence of DFSP in patients aged < 20 years is approximately 1 per 1 million, with myxoid DFSP accounting for 4% of all DFSPs. Herein, we report a case of myxoid DFSP in a young adult, an exceedingly rare occurrence, along with a review of the literature.[Skin Cancer (Japan) 2025 ; 40 : 121－126]
