An update on tumors of the anal canal.
BACKGROUND
The anal canal possesses complex anatomy and histology and gives rise to a variety of tumor types. Challenging issues remain with regard to both the pathologic diagnosis and the clinical management of these tumors.


OBJECTIVE
To provide an updated overview of the histogenesis, clinical and pathologic characteristics, diagnostic terminology, and relevant clinical management of the various types of anal canal tumors.


METHODS
Recent literature on clinical and pathologic characteristics of anal canal tumors.


CONCLUSIONS
Although most anal canal tumors are of squamous lineage, a complex variety of other tumors also occurs. Recognition of such diverse tumor entities will allow accurate pathologic diagnosis and most optimal clinical management.
Department of Pathology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065, USA. shiaj@mskcc.org
Jinru
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Shia
D000230:Adenocarcinoma / Q000473:pathology*; D001003:Anal Canal / Q000473:pathology*; D001005:Anus Neoplasms / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D006801:Humans; D008545:Melanoma / Q000473:pathology*