Peritoneal mesothelioma metastasis to the tongue – Comparison with 8 pleural mesothelioma reports with tongue metastases

PURPOSE: Malignant mesothelioma (MM) rarely arises from the peritoneum. We describe the 1st such case which metastasised to the head and neck region (tongue). METHODS: We briefly surveyed the American Surveillance Epidemiology and End Results (SEER) database, and the British Cancer Research UK database for the latest trends in MM incidence. We did a systematic Pubmed search for other MM reports with tongue metastases. RESULTS AND PRESENTATION OF CASE: American and British data show that MM incidence in men has stabilised in the last 10 years, earlier than previously predicted. The tongue is an unusual site for MM spread, with ours being only the 9th such case described. Our summary of published cases of MM metastasising to the tongue brings out our patient to be the least in age(35 years), and the only one to have peritoneal MM as the primary. Seven of the 9 cases were male. Only 2 had a recorded history of exposure to asbestos. All 9 patients had the epithelioid subtype of MM. Surgery was done as the exclusive reported intervention in 4 out of the 9 patients. Only 2 cases received radiotherapy, amongst whom, only our patient responded. CONCLUSIONS: Metastasis of MM to the tongue is rare and usually in the uncommon context of MM with multiple sites of extra-thoracic or extra-abdominal spread. We have described a unique clinical manifestation of a rare subtype of mesothelioma. Moreover, we have tabulated and summarised details (including responses to surgery or/and radiotherapy) regarding all reported cases of mesotheliomas with tongue metastasis.