title: Solitary dural plasmacytoma with conspicuous cytoplasmic inclusions.
abstract: A solitary intracranial plasmacytoma originated from the left parietal meninges of a 67-year-old woman; the patient had a four-month history of generalized seizures. Immunoelectrophoresis, performed nine months after surgery, revealed a monoclonal IgG band in the cerebrospinal fluid (CSF) but not in the blood. A peculiar feature of the tumor cells was the presence of abundant hyaline, eosinophilic cytoplasmic inclusions. Ultrastructurally, these inclusions consisted of electron-dense floccular material within distended cisterns of endoplasmic reticulum (ER). These ultrastructural features resemble "thesaurocytes" originally described by Paraskevas et al. in IgA myeloma. Tumors composed mainly of such inclusion-bearing cells are extremely rare. Only a fraction of the tumor cells stained positively for IgG with the immunoperoxidase technique; most inclusion-bearing cells did not stain. It is therefore unlikely that the electron-dense material is stored immunoglobulins.
mesh_terms: D003593:Cytoplasm / Q000648:ultrastructure; D005260:Female; D006801:Humans; D002479:Inclusion Bodies / Q000648:ultrastructure*; D008577:Meningeal Neoplasms / Q000473:pathology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D008875:Middle Aged; D010954:Plasmacytoma / Q000473:pathology* / Q000648:ultrastructure