AN AUTOPSY CASE OF DIFFUSE MALIGNANT MESOTHELIOMA OF THE PERICARDIUM

A report is presented of an autopsy case of a 71-year-old Japanese man with a diffuse malignant epithelial mesothelioma of the pericardium w ith massive pericardial effusion and a thickened pericardium. He had n o history of exposure to asbestos. He suffered severe heart failure an d later died. Autopsy revealed that the tumor had developed over the p ericardium. Microscopically, the tumor cells were arranged in an epith elial form, and histochemically, the cytoplasm of these cells containe d glycogen and hyaluronic acid. The tumor tissue showed immunohistoche mical positivity for cytokeratin, epithelial membrane antigen, vimenti n, cancer antigen 125, thrombomodulin, mesothelial antigen, muscle act in and human milk fat globule. In contrast, all the tumor cells were n egative for human carcinoembryonic antigen and epithelial antigen. Ult rastructurally, the tumor cells had long, thin microvilli, abundant in termediate filaments, intracytoplasmic lumina and long desmosomes. It is considered that the patient had a typical malignant epithelial meso thelioma of the pericardium.