Multisite recurrence of dermatofibrosarcoma protuberans with high-grade fibrosarcomatous transformation: a case report

Background. Dermatofibrosarcoma protuberans (DFSP) is a rare, locally aggressive soft tissue sarcoma with a high recurrence rate. The fibrosarcomatous transformation of DFSP (FS-DFSP) is associated with increased metastatic potential and poorer prognosis. Management typically involves wide surgical excision with clear margins, but recurrent and metastatic cases require a multidisciplinary approach, including radiation therapy and systemic treatment. Case presentation. We report a 37-year-old female with a history of recurrent DFSP involving the left posterior chest wall. She underwent multiple surgical resections in Egypt (2017, 2019, 2022), with a subsequent recurrence requiring wide local excision and adjuvant radiation therapy (50 Gy in 25 fractions) in 2022. In October 2023, evaluation revealed a recurrent 10×8 cm mass infiltrating the posterior chest wall. MRI confirmed the involvement of the underlying ribs and intercostal muscles. She underwent extensive resection with plastic reconstruction in November 2023, with pathology confirming Grade 3 FS-DFSP (14×13×6 cm) with negative margins. Postoperatively, wound healing progressed to 80%, and adjuvant AIM chemotherapy was planned. However, in November 2024, imaging detected a new 8.8×9×8 cm mass in the pancreatic head involving the superior mesenteric vein. Biopsy confirmed DFSP recurrence. The patient underwent ERCP with stent placement and was re-evaluated for further surgical and oncological management. Conclusion. This case highlights the aggressive nature of FS-DFSP with multisite recurrence, necessitating ongoing surveillance and a multidisciplinary treatment approach. Despite repeated resections and adjuvant therapies, disease progression underscores the need for novel therapeutic strategies to improve long-term outcomes in high-grade DFSP.