Evaluation of 5-fluorouracil in the treatment of actinic keratosis of the lip.

Topically applied 5-fluorouracil has recently gained acceptance in the treatment of actinic keratosis of the lip; however, histologic evidence confirming the effectiveness of the therapy has not yet been established. Pretreatment biopsies were performed on six patients to confirm actinic damage and grade the degree of dysplasia. After 5-fluorouracil therapy, biopsies of tissue adjacent to the previous biopsy sites were performed to determine the success of treatment. Histologic evaluation showed residual dysplasia in all posttreatment biopsy material, even though the clinical stigmata of the actinic lesions had been improved or eliminated.