Management of locally-advanced dermatofibrosarcoma protuberans: Four cases report

Dermatofibrosarcoma protuberans (DFSP) is a malignant skin tumor originated from of fibroblast, which remains a challenge in terms of diagnosis and treatment, especially in those with locally-advanced disease.

Case 1 is a 38-year-old male complained with a mass at his left temporal and left mandibular region, and invaded his left orbital region. Case 2 is a 54-year-old male with a mass located in this chest region. The tumor invaded 2th and 3rd ribs with suspicious intra-thoracic invasion. Case 3 is a 63-year-old male with a recurrent tumor in abdominal wall which invaded peritoneum of abdominal wall. Case 4 is a 11-year-old boy with a mass located in his left forearm, which invaded the abductor pollicis longus, extensor pollicis brevis, and extensor carpi radialis longus.

These 4 patients were diagnosed with DFSP with local invasion. Case 3 was pathologically diagnosed with reginal fibrosarcomatous transformation (FS-DFSP).

Case 1 received imatinib 400 mg/day as neo-adjuvant therapy. After 6 months, the mass significantly shrunk and Mohs surgical resection and reconstruction with free anterolateral thigh flap were performed. Case 2 received Mohs surgical resection and reconstruction with contralateral pedicled latissimus dorsi flap. Case 3 and Case 4 also received Mohs surgical resection of the tumor and construction with a free anterolateral thigh flap.

All of the 4 patients achieved clean margins by frozen section during surgery. At the last follow-up, none of them experienced disease recurrence.

Mohs micrographic surgery is an effective surgical technique for locally-advanced DFSP patients. Imatinib neo-adjuvant therapy is an option when surgical resection with negative margin may cause unacceptable functional or cosmetic outcomes.