title: Vacuolated cell mesothelioma of the pericardium resembling liposarcoma: a case report.
abstract: We report a case of localized pericardial mesothelioma with unusual histological features in a 44-year-old woman. Her radiological imagings showed an 11-cm pericardial tumor, between the heart and aortic arch. Microscopically, the tumor was predominantly composed of vacuolated cells and vaguely reminiscent of well differentiated "lipoma-like" liposarcoma, but only small foci of the tumor showed the papillotubular configuration. Histochemically, the tumor cells contained hyaluronic acid in the vacuoles but no lipids. Immunohistochemically, they showed immunoreactivity for cytokeratin, calretinin, vimentin, and epithelial membrane antigen. Ultrastructural study showed that the vacuoles of the tumor cells were intracytoplasmic lumina. The intracytoplasmic lumina and the surface membranes of the tumor cells had many long and slender microvilli with focal bush-like appearance. Desmosomes between adjacent cells were occasionally observed. To our knowledge, this is the first case report of epithelial type mesothelioma predominantly composed of vacuolated tumor cells, microscopically mimicking liposarcoma.
authors.affiliation: Department of Laboratory Medicine and Surgery II, National Defense Medical College Hospital, Tokorozawa, Saitama, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Shimazaki
authors.forename: S
authors.initials: S
authors.lastname: Aida
authors.forename: Y
authors.initials: Y
authors.lastname: Iizuka
authors.forename: H
authors.initials: H
authors.lastname: Yoshizu
authors.forename: S
authors.initials: S
authors.lastname: Tamai
mesh_terms: D000328:Adult; D064032:Calbindin 2; D003937:Diagnosis, Differential; D005260:Female; D006338:Heart Neoplasms / Q000175:diagnosis / Q000473:pathology*; D006651:Histocytochemistry; D006801:Humans; D006820:Hyaluronic Acid / Q000032:analysis; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis; D008080:Liposarcoma; D008654:Mesothelioma / Q000175:diagnosis / Q000473:pathology*; D008854:Microscopy, Electron; D018396:Mucin-1 / Q000032:analysis; D010496:Pericardium / Q000473:pathology*; D064030:S100 Calcium Binding Protein G / Q000032:analysis; D014617:Vacuoles / Q000473:pathology*; D014746:Vimentin / Q000032:analysis
chemical_list: C576764:CALB2 protein, human; D064032:Calbindin 2; D018396:Mucin-1; D064030:S100 Calcium Binding Protein G; D014746:Vimentin; D007633:Keratins; D006820:Hyaluronic Acid