Soft tissue sarcomas in dermatology.

BACKGROUND: Dermatofibrosarcoma protuberans, atypical fibroxanthoma, and cutaneous leiomyosarcoma are uncommon soft tissue sarcomas that tend to have a high recurrence rate when removed with standard excisional surgery, and in some cases have been reported to metastasize. These tumors have been reported in the surgical, medical, and pathology literature. The diagnosis and treatment of these tumors is still evolving. Wide excision and surgical techniques involving meticulous surgical margin control appear to be the most efficacious treatment for these problematic tumors.

OBJECTIVE: The surgical, medical, and pathology literature was extensively reviewed to collate the observations of multiple investigators, and to summarize their findings. Literature from medical journals of multiple subspecialties as well as textbooks were reviewed with particular emphasis on diagnosis, histologic features including immunohistochemistry, and useful surgical techniques that facilitate the removal of these difficult tumors.

RESULTS: Dermatofibrosarcoma protuberans is a soft tissue neoplasm of intermediate malignancy that shows a high recurrence rate when treated with standard excision. Wide surgical excision using a 3-cm margin greatly reduces the risk of recurrence, but is not practical in some cases. Evidence is continuing to accumulate that Mohs micrographic surgery may be the treatment of choice for this tumor. Atypical fibroxanthoma is best thought of as a superficial form of malignant fibrous histiocytoma. It is histologically indistinguishable from certain forms of malignant fibrous histiocytoma and differs primarily in its size and superficial location. These tumors are best removed surgically. For most smaller tumors a 1-cm margin, which is carried down to the subcutaneous tissue, provides adequate treatment. In cases where tissue conservation is important, Mohs micrographic surgery has been shown to be very effective. Cutaneous leiomyosarcoma is a rare superficial soft tissue sarcoma that has a high incidence of recurrence after excision and can metastasize. Because of the small number of patients treated, treatment recommendations are still evolving. Currently, wide local excision is recommended with a 3-5 cm margin and removal of the underlying subcutaneous tissue. Mohs micrographic surgery has been used in a small number of cases with good success.

CONCLUSION: Dermatofibrosarcoma protuberans, atypical fibroxanthoma, and cutaneous leiomyosarcoma are soft tissue sarcomas that have a high rate of recurrence when treated with standard surgical techniques and may occasionally metastasize. When removing these tumors it is very important to take adequate margins. Mohs micrographic surgery is proving to be very useful in treating these difficult neoplasms.