Patients treated with mitomycin will be handled by cycles until resolution of the lesion, which according to previous studies is expected between 3 and 6 cycles (between half months and 3 months). Patients managed with interferon will be treated for a period ranging from one month to 12 months according to clinical resolution of the lesion. Both groups will be evaluated by at least one year after the resolution of the lesion to determine the presence of recurrences.