Primary rectal malignant melanoma: report of two cases.

Primary rectal malignant melanoma is an exceptionally rare neoplasm associated with an extremely poor prognosis despite aggressive surgical treatment. We present two female patients with bulky tumors of the lower rectum that were diagnosed as malignant melanoma, above the squamocolumnar junction. Both patients underwent abdominoperineal resection and postoperatively were treated with autologous melanoma cell vaccine. One patient is considered disease free for months after surgery; the second one developed supraclavicular lymph nodes and right lung metastasis after 7 months.