Ampulla of Vater

Tumors involving the anorectal junction should be classified as rectal cancers if the epicenter is more than 2 cm proximal to the dentate line and as anal cancers if the epicenter is 2 cm or less from the dentate line.2. Cancers that arise in the perianal skin are termed “perianal cancers” and are biologically similar to other skin tumors. ................
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