How should premalignant lesions, such as actinic keratoses and actinic cheilitis, be treated?

We should probably first ask, “Why should premalignant lesions be treated?” While a small percentage of actinic keratoses regress spontaneously, up to 20% develop into squamous cell carcinoma. Treating actinic keratosis can therefore prevent the development of SCC. Additionally, small SCCs are difficult to separate from actinic keratoses on clinical exam. The smallest SCCs are often picked up when a suspected actinic lesion does not respond to treatment or a lesion appears in a treated area.

Since actinic lesions can vary from tiny, barely palpable lesions to an entire lip or scalp, treatment modalities depend on the size and location of lesions. Small, individual papules can be treated by cryosurgery or by curettage (usually after local anesthesia). Larger areas can be treated by cryosurgery, curettage, dermabrasion, chemical peels, imiquimod, and topical 5-fluorouracil. Laser ablation (CO₂ laser) and excision with mucosal advancement are reserved for extensive involvement of the lip.