Anal Adenocarcinoma within Anorectal Fistula

**Semantic type:** Neoplastic Process

**Definition:** An anal adenocarcinoma arising from the lining of an anorectal fistulous tract. The overlying anal mucosa does not show evidence of neoplastic changes. Some cases are associated with Crohn disease.

**Synonyms:** - Adenocarcinoma of Anus within Anorectal Fistula - Adenocarcinoma of the Anus within Anorectal Fistula