ARM I: Patients are directed to receive either topical or ablative treatment at the discretion of the clinician. Patients receiving topical treatment apply imiquimod intra-anally, peri-anally or both thrice weekly for up to 16 weeks, fluorouracil twice daily for 5 days every 2 weeks for up to 16 weeks, or trichloroacetic acid every 3 weeks up to 12 weeks. Patients receiving ablative treatment using infrared coagulation, hyfrecation/electrocautery, or laser. Patients may undergo excision under anesthesia if the clinician believes none of the other treatment approaches will be effective. The number and timing of such treatments will be at the discretion of the investigator. Patients with persistent HSIL should continue a protocol-approved treatment or a new protocol treatment should be considered.