Abstract
A 21-year-old woman complained of a small nodule on her left lower leg that she had first noted at the site of an insect bite when she was 16 years old. The nodule became larger, and was 20×20 mm in size when she visited our hospital. It had a smooth surface and was clearly demarcated from the surrounding skin, but there was neither pain nor irritable sensation. The nodule was diagnosed as a hypertrophic scar arising after an insect bite and treatment using an adhesive tape containing steroid was started. Two months later, as the cystic region had become prominent, an excisional biopsy was performed and the specimen was diagnosed as dermatofibrosarcoma protuberans. A wide local excision was undertaken with a 5 cm margin that included a deep fascia. The defect was covered with artificial dermis and a split thickness skin graft. The patient had no recurrence or metastasis in the 6 months after the first operation.
As the tumor here resembled a keloid or hypertrophic scar in the early stages, it is recommended that physicians need to suspect a possible malignant tumor if a treatment resistant keloid or hypertrophic scar is presented.
Optimal resection of dermatofibrosarcoma protuberans and the application of Mohs micrographic surgery for such tumors are discussed. [Skin Cancer (Japan) 2002; 17: 205-208]
