Treatment protocol: Patients will apply imiquimod daily for 14 days on the tumor and a rim of 2mm around the tumor. On day 14 a session of mild cryosurgery (2 cycles of 10-15 seconds, with open spray liquid nitrogen) will be applied and the patients will continue application of imiquimod for another 3 weeks before being evaluated again. Persisting erosion will be considered as persistence of the tumor and imiquimod will be continued for another 3 weeks with/or without a cryosurgery session. The patients will be evaluated at 1,3,6,12 months after discontinuation of imiquimod and yearly thereafter for relapse. In case of clinical relapse, it will be confirmed by biopsy.