The patient was an 8-year-old boy, who consulted our department on May 25, 1999, because of a black spot in the maxillary gingiva. He had under-gone application of saforide® in CB_??_ in a dental clinic 5 years previously. Thereafter, he noted a black spot in the surrounding gingiva, but because of no pain, it was left untreated. Recently, the patient consulted a dental clinic due to an increase in the size of the spot. He was then referred to our department. Intraoral examination revealed a flat dark brown spot (11×6mm) in the buccal gingiva around 2_??_, showing infiltration into the surrounding tissue. There was also a localized flat black spot (1×1mm) besides the dark brown spot. Based upon these clinical findings pigmented nevus or malignant melanoma was suspected. As a result of biopsy performed on May 25 using cryosurgery, histopathologically they were diagnosed as cellular blue nevi. On June 25, the spots were removed together with the surrounding gingiva and periosteum. The course has been uneventful these 8 months after the surgery without a sign of recurrence.
