A Case of Actinic Keratosis Successfully Treated with Imiquimods+Histological Observations during Therapy

Abstract

A case of actinic keratosis in a 78-year-old woman is reported. Erythema on her middle finger showed atypical cells along the basal layer histologically. The application of imiquimod cream, which has not been approved in Japan, was her choice among the therapeutic options. According to the successful clinical case report, imiquimod was applied three times a week for 12 weeks, and the atypical cells disappeared completely without any recurrences to date. The cosmetic outcome was excellent. During the therapy, a dense lymphocytic infiltration was observed, and some of the cell showed exocytosis. Using immunohistochemical staining, it became apparent that these cells were CD1a, Granzyme B, and CD20 positive. We concluded that imiquimod can be a good treatment option for actinic keratosis, because it stimulate an immune response.