Anal high-grade squamous intraepithelial lesions: identification, classification, and management

Area of Science:

• Oncology
• Virology
• Gastroenterology

Background:

• Squamous intraepithelial lesions (SILs) are premalignant conditions for anal cancer, a malignancy with slowly increasing global incidence.
• High-risk individuals, including immunosuppressed persons and men who have sex with men, are commonly affected by SILs.
• Chronic human papillomavirus (HPV) infection, particularly high-risk genotypes like HPV 16 and 18, drives SIL development and progression to invasive cancer.

Purpose of the Study:

• To review the current understanding and classification of anal squamous intraepithelial lesions.
• To emphasize the importance of screening and proactive treatment of high-grade SILs (HSIL) in at-risk populations.
• To highlight the role of high-resolution anoscopy in the diagnosis and management of anal dysplasia.

Main Methods:

• Review of historical and current classification systems for anal intraepithelial neoplasia (AIN).
• Discussion of diagnostic modalities, focusing on high-resolution anoscopy with vital dyes and magnification.
• Exploration of the potential impact of artificial intelligence on diagnostic capabilities.

Main Results:

• Anal intraepithelial neoplasia is classified by the degree of dysplasia: AIN I (low-grade SIL) may regress, while AIN III (high-grade SIL) can progress to invasive cancer.
• Proactive treatment of HSIL is established as a crucial strategy for reducing anal cancer development.
• High-resolution anoscopy enables visualization and treatment of subtle premalignant lesions, improving diagnostic accuracy.

Conclusions:

• Active screening and timely treatment of HSIL are essential for preventing anal cancer in high-risk individuals.
• High-resolution anoscopy is a key tool for identifying and managing anal dysplasia, thereby halting progression to squamous cell carcinoma.
• Advancements in artificial intelligence are expected to further refine diagnostic accuracy and ease of use for high-resolution anoscopy.