Simultaneous triple primary malignant melanomas occurring in the buccal mucosa, upper gingiva, and tongue: A case report ☆

Abstract Malignant melanoma of the oral cavity is a rare disease. Here, we present an extremely rare case of simultaneous triple primary malignant melanomas occurring in the buccal mucosa, upper gingiva, and tongue. A 97-year-old male was referred because of tumors of the right buccal mucosa and left upper gingiva. Macroscopically, neither the tumors nor the adjacent mucosae exhibited melanin pigmentation. Biopsies of the two lesions showed that both were malignant melanomas. The patient underwent resection of the two tumors and right neck dissection. A histological examination of the surgical specimens demonstrated primary malignant melanomas and a metastatic lymph node. Most of the tumor cells were amelanotic, but displayed positive reactions for S100 or HMB45. One month after surgery, a small amelanotic nodule appeared on the dorsum of the patient's tongue. An excisional biopsy demonstrated that this was also a primary malignant melanoma. The patient is well at 6 months after the initial surgical procedure.