[Primary Malignant Pericardial Mesothelioma;Report of a Case].

A 69-year-old male was referred to our hospital after being diagnosed as having pericarditis with pericardial effusion. The symptoms of tamponade disappeared after the effusion was drained;although the cause of pericarditis remained unidentified. About 4 months later, the tamponade symptoms recurred due to the thickened nodular pericardium. Partial pericardiectomy was performed, however the patient died on the 52nd day after surgery. Immunohistological examination with calretinin led to the diagnosis of primary malignant pericardial mesothelioma, which was an extremely rare pathology. Because the hyaluronic acid content of the effusion has been reported as a diagnostic aid for malignant mesothelioma, routine examination of the hyaluronic acid content for pericarditis with pericardial effusion may be necessary for early diagnosis and to improve prognosis.