title: Synchronous Primary Anorectal Melanoma and Sigmoid Adenocarcinoma.
abstract: A primary anorectal malignant melanoma is a rare tumor. Moreover, cases involving a synchronous anorectal melanoma and colon adenocarcinoma are extremely rare. The authors report a case of a synchronous anorectal melanoma and sigmoid adenocarcinoma in an 84-year-old man. The regions of the anorectal melanoma showed melanocytic nevi in the adjacent mucosa of the anal canal and rectum. A dysplastic nevus was also identified in the anal mucosa. This case demonstrates that an anorectal melanoma can arise from pre-existing anorectal melanocytic lesions.
authors.affiliation: Department of Pathology, Chosun University School of Medicine, Gwangju, Korea.
authors.forename: Inju
authors.initials: I
authors.lastname: Cho
authors.affiliation: Department of Surgery, Chosun University School of Medicine, Gwangju, Korea.
authors.forename: Kyung Jong
authors.initials: KJ
authors.lastname: Kim
authors.affiliation: Department of Pathology, Chosun University School of Medicine, Gwangju, Korea.
authors.forename: Sung-Chul
authors.initials: SC
authors.lastname: Lim
keywords: Adenocarcinoma; Anus; Melanoma; Rectum; Sigmoid colon