REACTIVE LENTIGINOUS HYPERPIGMENTATION AFTER CRYOSURGERY FOR LENTIGO-MALIGNA

Background: Twenty patients treated for lentigo maligna of the face with cryosurgery developed benign lentiginous hyperpigmentation mimicking a recurrence. Objective: When cryosurgery is used in the treatment of lentigo maligna, it is important to know whether repigmentation of the scar represents true recurrence or a benign process. Methods: Twenty patients were treated with cryosurgery for lentigo maligna of the face. Within a follow-up period of 7 to 80 months, frequent clinical observations were made. Results: Lentiginous hyperpigmentation developed within the treatment area in eight patients. Histologic investigation revealed recurrence of lentigo maligna in three and benign hyperpigmentation in five. Conclusion: Genetic factors and UV exposure after cryosurgery may favor the development of benign lentiginous hyperpigmentation. Because recurrence of lentigo maligna must be considered, histologic evaluation of repigmentation is mandatory.