Anorectal melanoma: successful treatment by surgical excision and combination chemoimmunotherapy.

Anorectal melanoma is an extremely rare malignancy, and has a poor prognosis mainly due to delays in diagnosis and lack of effective systemic therapy. We report the case of a 63-year-old female patient with anorectal melanoma. Diagnosis was established after surgery by histology and immunohistochemistry. Surgical management consisted of abdominoperineal resection of the rectum. Postoperatively, the patient received combination therapy of dacarbazine, nimustine hydrochloride, vincristine sulfate, and interferon-beta for 3 cycles. Ten months later, a solitary brain metastatic tumor was noted in the left occipital region, which was resected surgically followed by the above combination therapy for 2 cycles. The last metastatic work-up was normal, and no evidence of recurrence was observed at 2-year follow-up. In our case, abdominoperineal resection of the rectum appears to have some effect in preventing regional and lymph node recurrence. Furthermore, our case suggests that prolongation of survival may depend on extensive block resection and combination therapy of DAV and interferon-beta.