Free Osteocutaneous Fibular Flap for Hand Reconstruction Related to Clear Cell Sarcoma Resection: A Case Report

We present a 25-year-old female with a two-year history of clear cell sarcoma (CCS) of the hand. The patient presented with a painless left hypothenar tumor without neurological or functional compromise. MRI was compatible with sarcoma (4.8x3.4x4.9cm) and incisional biopsy confirmed CCS by immunohistochemistry (MITF1 and EWSR1 rearrangement both positive). The patient received preoperative radiotherapy for tumor reduction (approximately 80%). A wide resection was performed with negative margins of 2 cm, including third-fifth metacarpals, partial carpectomy and amputation of the fifth finger due to intraoperative ischemia. The lesion was reconstructed with a free fibula flap whose survival and postoperative short-term evolution were favorable. Six months after surgery, the patient presented partial mobility under rehabilitation with no evidence of recurrence or metastasis. Disabilities of the Arm, Shoulder and Hand (DASH), Musculoskeletal Tumor Society (MSTS) score, grip and pressure strength could not be determined. Our case is very particular due to the hypothenar involvement with central multistructural involvement and an atypical slow evolution. The aggressive therapeutic approach with microsurgical resection, reconstruction and functional preservation using a multisegmented fibula free osteocutaneous flap was favorable for the patient's outcome.