Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare, low-grade soft tissue neoplasm that typically arises in the extremities. A 72-yearold woman presented with recurrent masses on her left forearm. Four years prior, she underwent an excisional biopsy, diagnosed as MIFS, followed by wide excision and split-thickness skin graft coverage. Preoperative magnetic resonance imaging was conducted for the recurrent mass, revealing multiple tumors invading the flexor digitorum profundus (FDP) muscle and fascia. The tumors including most of the FDP muscle were therefore excised. The third flexor digitorum superficialis (FDS) tendon was harvested, divided in half, and connected to the second and fifth FDP tendons. The same procedure was performed for the third and fourth FDP tendons with fourth FDS tendon. An anterolateral thigh free flap was used to reconstruct the skin and soft tissue defect of the left forearm. Adjuvant radiation therapy was performed. At 12 weeks postoperatively, the patient exhibited no wound complications and achieved spontaneous partial flexion of the metacarpophalangeal and proximal interphalangeal joints.