Dermatofibrosarcoma Protuberans Arising in a Digit: A Case Report

Dermatofibrosarcoma protuberans (DFSP) is a rare slow-growing soft tissue sarcoma that is usually found on the trunk or extremities. This report highlights an exceedingly rare case in which a DFSP arose on the digit of a 43-year-old man. Clinical and histologic analysis revealed an atypical CD34-positive tumor with differentials including DFSP and multiple similar entities. However, fluorescence in situ hybridization studies revealed a COL1A1 translocation to the platelet-derived growth factor B (22q13.1) locus, t(17;22)(q22;q13), confirming the diagnosis of DFSP. Although rare, this case highlights the importance of including DFSP on the differential in CD34-positive acral tumors, with cytogenetic analysis crucial for accurate diagnosis and treatment.