A case report of metastasis of malignant mesothelioma to the retromolar trigone

Malignant mesothelioma is a rare and aggressive tumor with a poor prognosis. Distant metastases are very rare, and the oral cavity metastases are exceedingly rare. Only a few cases with metastasis to oral gingiva are reported. To our knowledge, this is the first case report of pleural mesothelioma metastasized to the retromolar trigone.

A 59-year-old male was referred with a painless growth at retromolar trigone area. It had been present for 2 months and had increased in size during this period of time. Past medical history revealed a malignant mesothelioma. Intraoral examination showed a soft, haemorrhagic, ulcerated lesion at the right retromolar trigone area. There was no destruction of the bony architecture. An incisional biopsy was performed under local anaesthesia. Based on the histopathological and immunohistochemical findings, a final diagnosis of metastatic mesothelioma was made. The patient was informed about the possibility of multiple metastases within the body, but he succumbed after 45 days following deterioration of his medical condition.

Biopsy, history of the patient and clinical picture were provided to the clinicians to make an efficient differential diagnosis. Differential diagnosis must be performed with other oral cancers, because the management is totally different.