Primary malignant melanoma of the oral mucosa

The occurrence of primary oral melanoma is very rare. Large clinical series suggesting appropriate treatment modalities are lacking; the clinician has to rely on case reports to gain insight into the management of this tumor, which is much more aggressive than its skin counterpart. Patients and methods The cases of 5 patients with primary oral melanoma during a 6-year period were retrospectively reviewed. Four patients presented with tumors located in the maxilla. Preoperative workup included microscopic examination of incisional biopsy specimens for the confirmation of the diagnosis and thorough imaging of the body to rule out distant metastases. Histologically significant vertical invasion was found in all patients. No patient had distant metastases initially, and only 1 patient presented with neck disease. Primary treatment included wide local excision in 4 patients and therapeutic modified radical neck dissection in the 1 patient with neck node involvement on presentation. One patient was treated primarily with radiation therapy due to medically compromised status. Adjuvant immunochemotherapy (DAV protocol) was administered to 4 patients. Radiation therapy was used in an adjuvant fashion in 3 patients.

All of the patients developed distant metastases to the lung and liver and eventually died of their disease. Survival ranged from 14 to 38 months (mean, 25.6 months). Local recurrence occurred in 1 patient and was attributed to positive surgical margins. Contralateral neck disease developed in the patient who underwent therapeutic neck dissection.

The prognosis of primary oral melanoma remains poor despite adequate locoregional control of the disease. It seems that diagnosis is made late in the course of the disease when the primary tumor has already shed microscopic distant metastases.