Anal Margin Carcinoma

**Semantic type:** Neoplastic Process

**Definition:** A carcinoma arising in the anal margin or perianal skin (below the anal verge and involving the perianal hair-bearing skin). It includes basal cell and squamous cell carcinoma. Anal margin carcinoma is staged as a skin carcinoma, separately from anal canal carcinoma.

**Synonyms:** - Anal Margin Cancer - Carcinoma of Anal Margin - Carcinoma of the Anal Margin - Perianal Skin Carcinoma