**1. Introduction**

Anorectal melanoma (AM) is a rare type of anorectal malignancy. It accounts for about 1% of all anal cancers [1]. Due to its rarity, it is often misdiagnosed as hemorrhoids, rectal adenocarcinoma and polyps. Its early diagnosis and treatment are important to improve the prognosis as it is an aggressive disease with high malignant potential. There are no standard guidelines for the diagnosis, staging and treatment of AM. In this chapter, we have discussed the epidemiological, pathogenesis, clinical manifestations, treatment and prognosis of AM.

## **2. Epidemiology**

Mucosal melanoma (MM) accounts for 1–2% of all melanomas with incidence of 2–2.6 cases per million people/year [2]. The most common sites of MM are head and neck followed by anorectal region [3]. AM is the most common type of gastrointestinal melanoma and the third most common type of melanoma [3]. AM accounts for 16.5% cases of mucosal melanomas [4]. The annual incidence rate of AM is 0.259 in males and 0.407 in females according to Surveillance, Epidemiology, and End Results (SEER) analysis and, the incidence has been steadily increasing over the years [5, 6]. However, the exact reasons for rising incidence are poorly understood. The prevalence of AM is 1.6 to 2.3 times higher in females than males and two times higher in Caucasians than African Americans [7, 8].
