dermatofibrosarcoma protuberans dfsp with fibrosarcomatous transformation a case report

Abstract Case Report: We report a case of a 40 year-old woman, who consulted for an infraumbilical 5cm cutaneous node, the third recurrence of a fibrocystic lesion. An expert sarcoma pathologist analyzed the previous histopathological samples, and suspected a DFSP, finding a positive rearrangement for the PDGFB gene (derived growth factor beta polypeptide). Surgical removal with wide local excision was performed. The histopatological analysis showed a mesenchymal proliferation with storiform pattern according to a DFSP, and a fishbone pattern with fusiform cells corresponding to a fibrosarcoma in the deeper region. Backgrounds: DFSP is a rare soft tissue tumor affecting young adults, and has been related to a chromosomal translocation t(17;22)(q22;q13), presented in 90% of the cases, that results in a fusion protein COL1A1-PDGFB (collagen type 1A1). It is usually presented as an indurated skin plaque, involving dermis and subcutaneous fat. It has a high risk of local recurrence (10-60%), being weird lymphatic dissemination and distant hematogenous metastasis (4-5%). Histologically it is characteristic fusiform cells with a storiform pattern (cellular swirls). The treatment is surgical removal with wide local excision. It has a 10-year overall survival of 99%. It has been described de fibrosarcomatous degeneration (7-16% of the cases), with more aggressive behavior, a higher local recurrence and distant metastasis rate. Conclusion: A proper identification of this type of tumors may change the surgical procedure and disease prognosis, so they must be managed by expert pathologists and a Multidisciplinary Team on soft tissue sarcomas in order to achieve the best results. Keywords Dermatofibrosarcoma; Protuberans; Soft tissue; Fibrosarcoma