Anal anatomy and normal histology

Area of Science:

• Anatomy
• Histology
• Oncology

Background:

• The anal canal's anatomy and histology are crucial for understanding anal cancers.
• Traditional terminology for the anal region has undergone recent revisions.

Purpose of the Study:

• To describe the gross anatomy, blood supply, venous and lymphatic drainage, and nerve supply of the anal canal.
• To highlight recent terminology changes adopted by the American Joint Committee on Cancer.
• To explain the clinical relevance of anal canal anatomy and histology to anal cancers.

Main Methods:

• Review of anatomical and histological literature.
• Description of gross anatomy and neurovascular and lymphatic supply.
• Explanation of revised terminology for the anal region.

Main Results:

• Detailed description of the anal canal's gross anatomy.
• Elucidation of the anal canal's blood supply, venous and lymphatic drainage, and nerve supply.
• Introduction of new terminology separating the anal region into the anal canal, perianal region, and skin.

Conclusions:

• Updated terminology assists clinicians in precise lesion identification without instrumentation.
• Knowledge of anal canal anatomy and histology is vital for accurate diagnosis and management of anal cancers.