Management Of Anal Dysplasia

Anal dysplasia represents a spectrum of disease that ranges from benign to malignant changes in the anal epithelium. These changes are the result of chronic infection with the human papillomavirus (HPV). The incidence and prevalence of both anal high-grade squamous intraepithelial lesions (HSILs) and anal squamous cell carcinoma (SCC) have steadily increased in past decades. Anal HSIL is believed to be the precursor of anal SCC. The malignant progression rate ranges from 5% to 50%. Risk factors for the development of anal HSIL include infection with oncogenic FIPV serotypes, impaired immunity, anoreceptive intercourse, concurrent infection with HPV along the anogenital tract, and presence of other sexually transmitted infections. Thus, in certain populations, there is a role for screening with anal cytology. Diagnosis of HSIL is usually incidental when patients are taken to the operating room for other anorectal pathology. Furthermore, lesions are often invisible to the eye. Thus, diagnosis is facilitated by performing high-resolution anoscopy (HRA), which involves the placement of acetic acid in the anal canal, and using an operative microscope or colposcope to search for areas of acetowhitening and vascular changes, which are diagnostic of HSIL. Once identified, lesions can be destroyed with infrared coagulator ablation or electrocautery. Other treatment modalities include expectant management, application of topical 5-fluorouracil, photodynamic therapy, and mapping followed by wide local excision. Use of HRA-guided ablation has minimal morbidity and, compared with other strategies, is associated with a lower malignant progression rate (1% vs. 11%-50%).