An update on tumors of the anal canal.

CONTEXT

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.

OBJECTIVES

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.

DATA SOURCES

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.