A Rare Case of Primary Malignant Pericardial Mesothelioma Diagnosed with Pericardiotomy

Primary malignant pericardial mesothelioma (PMPM) is an extremely rare and lethal cardiac tumor. This article presents a 62-year-old man with recurrent pericardial fluid. The patient's clinical symptoms and imaging features were nonspecific. Initial diagnosis was constrictive pericarditis. After admission, the patient's symptoms worsened, and echocardiography indicated increased pericardial effusion. To diagnose and improve the patient's symptoms, pericardiotomy was performed; however, the procedure was unsuccessful because the pericardium was densely adherent to the myocardium. Histopathological examination, including immunohistochemical staining of the pericardial specimen revealed malignant mesothelioma. We recommended adjuvant therapy for the patient with cis-platinum and pemetrexed; however, the patient and his family refused treatment. The patient was discharged 11 days after surgery. The patient survived for more than 15 months with surgical treatment. In this report, the patient's symptoms improved, and the patient survived beyond the median survival after surgical treatment.   Conclusion: The definitive diagnosis of PMPM mostly has been obtained from specimens obtained by surgery. Surgery is an effective treatment method because it prevents cardiac tamponade and can improve symptoms or prognosis, but complete resection is impossible.