Malignant melanoma of the anus

Abstract

The authors present a report of 12 patients with anal melanoma (AM) and review 255 cases reported since 1947. Combining these patients with those from the literature, the authors analyze several aspects of AM that are controversial or have not been studied in a systematic manner. The mean clinical tumor size was 4.1 cm. Seventy per cent were grossly pigmented, 63 per cent were polypoid, and 44 per cent were prolapsed. Two-thirds of AM were located in the proximal pecten, at or near the level of the anal valves. Microscopically, the most useful diagnostic criteria were melanin production, junctional change, and a nesting growth pattern. In four of the authors' cases, atypical junctional change extended laterally from the overt invasive neoplasm for distances up to 1 cm. Approximately 60 per cent of patients had metastases at the time of diagnosis. There was no statistical difference in determinate survivals of patients treated for cure by local excision and abdominoperineal resection. Neither tumor size nor configuration affected survival. The choice of therapy was not influenced by tumor size.

Primary Malignant Melanoma of the Rectum: Report of Two Cases

“…The clinical diagnosis may be incorrect in 80% of all cases [1, 2, 18]. Because of delayed diagnosis and rapid progression, malignant rectal melanomas have been accompanied by distant metastases in 60% of patients at the time of final diagnosis [4, 13]. The two present cases had a chief complaint of rectal bleeding, and clinical diagnosis before surgery was rectal carcinoma.…”

“…Malignant melanomas occur frequently in the anorectum because of the presence of abundant melanocytes in the mucosa of the anal canal. The reported 5-year overall survival rate is 6%–15% of patients after surgery [4, 5, 7, 11–13]. Several studies have reported cases of long-term survival [14–16].…”

Primary anorectal malignant melanoma treated with neoadjuvant chemoradiotherapy and sphincter-sparing surgery: A case report

“…Surgery as a primary treatment strategy for PAMM, ranges from abdominoperineal resection (APR) to wide local excision (WLE). However, previous studies comparing the difference in survival time of patients treated by APR or WLE identified no statistical difference (10,13). In a number of studies, adjuvant chemotherapy (14), adjuvant radiation (15), neoadjuvant radiation (16) and immunotherapies (17) have also been used in PAMM, and certain curative effects were obtained.…”

The clinical features and optimal treatment of anorectal malignant melanoma

“…Traditionally, APR is regarded as the standard surgery for AMM [7,21,22]. APR is preferred because it can control lymphatic spread (mainly to mesenteric lymph nodes) and guarantee a larger negative margin for local control [23].…”