Abstract
Background: The coexistence of malignancies close to each other on the skin has been occasionally reported. The concept of field cancerogenesis applies to such cases. Given the purported mechanism of action of imiquimod, it should not be surprising that this treatment could inhibit epidermal field cancerogenesis. Aim: To assess the effect of imiquimod applied twice weekly on incipient bowenoid changes disclosed in the vicinity of basal cell carcinomas. Materials and Method: Biopsies were taken before treatment and after 4–6 weeks and 12 weeks of imiquimod treatment. Results: Large atypical bowenoid keratinocytes and dyskeratotic cells were cleared in time while factor-XIIIa-positive dermal dendrocytes appeared boosted and admixed with a brisk lymphocytic infiltration. Conclusion: Epidermal field cancerogenesis appears to be controlled by imiquimod. Dermal dendrocytes might play a pivotal role in this regression phenomenon.