Primary Anorectal Melanoma

Abstract

Primary malignant melanoma of the anus and rectum is a rare and aggressive neoplasm that tends to invade locally and metastasize early in the course of the disease. It is often misdiagnosed as hemorrhoids or as one of the other benign anorectal conditions and is thus linked to an overall poor prognosis and a 5-year survival rate of less than 20%. Optimal treatment is still controversial, and current evidence does not show any preferential survival benefit from abdominoperineal resection over wide local excision. Chemotherapy or radiotherapy may be used for advanced disease. We report a 71-year-old female presenting with painful bowel movements and blood in stools. She was eventually found to have a mass arising from the anorectal junction with regional lymph node involvement. The patient underwent an abdominoperineal resection and is currently scheduled for chemotherapy.

Primary anorectal melanoma: a case of 5 year disease-free survival

“…[7][8][9] Anorectal melanoma commonly affects the elderly in their sixth or seventh decade of life, with a 1.7 -fold higher prevalence in Caucasians than in African Americans. 1 Some authors report a possible female predominance, but most publications do not suggest significant gender differences and individual series are too small to draw definitive conclusions. [7][8][9][10][11] Lesions are usually polypoid, often ulcerated and easy to bleed, with or without pigmentation.…”

“…It accounts for 0.25-1.25% of all anorectal malignancies and is the third most common site for melanoma, after the skin and eye. 1 Anorectal melanoma affects mainly people aged 50-80 years, with peak incidence in the sixth and seventh decades of life. There are no significant gender differences, whereas the Caucasian race seems to be more frequently affected than African American individuals.…”

“…There are no significant gender differences, whereas the Caucasian race seems to be more frequently affected than African American individuals. 1 Diagnosis is often delayed, since symptoms are frequently nonspecific and easily mistaken for more benign conditions, such as hemorrhoids. Radical surgery is the mainstay of treatment, while the role of adjuvant chemotherapy, immune therapy and radiotherapy is yet to be established.…”

Spindle anorectal melanotic melanoma in a 70 year old woman

“…3 Melanomas constitute only approximately 0.5% of all colorectal and anal cancers. 2,4 Approximately one melanoma is seen for every 250 adenocarcinomas of anorectal region. 13 Anorectal region is the third most common location of melanoma involvement, skin being the first followed by ocular region.…”

“…13 Anorectal region is the third most common location of melanoma involvement, skin being the first followed by ocular region. 2,4 Lesions may affect the anal canal, rectum or both. Majority of melanomas occur within 6 cm of the anal rim.…”