A case of amelanotic malignant melanoma occurring on the palatal gingiva side of the upper right molar, in a 43-year-old male is presented.
The patient was first seen on September 14, 1995, with the chief complaint of rapid growth and alteration in the color tone of the tumor to ash albedo or redishness.
Initially, we suspected cancer or sarcoma on the basis of oral observations of the ulcerous, nodular mass.
Examination of a biopsy specimen showed the tumor to be composed of a solid proliferation of round and spindle shaped cells characterized by atypia, mitosis and many nuclei. Many tumor cells showed positive immunoreactivity for 5-100 protein, vimentin and HMB-45 mono clonal antibody.
Recognition of premelanosome with electron microscopic obsarvation confirmed the crigiral diagnosis.
Partial resection of the maxilla was performed under general anesthesia on October 3, 1995. The patient was observed periodically and no evidence of recurrent or metastatic lesion was found one year after the operation.