title: Primary malignant lymphomas of the central nervous system in man.
abstract: Sixty-eight primary malignant lymphomas of the CNS exclusively confined to the brain and its leptomeninges from a series of about 8000 intracranial neoplasms (incidence 0.85%) were examined and classified according to current histopathologic criteria. Average age at onset of symptoms was 55 years, mean duration of illness to time of diagnosis was 3 months. Survival averaged 1,8 months with supportive care, but 17,2 months with surgery, radiation and/or chemotherapy. CSF cytology was useful and reliable tool for clinical diagnosis. The cerebral hemispheres were affected in about 50%, the basal ganglia in 18%, posterior fossa in 10%, while multifocal lesions amounted to 22%. All CNS tumors were of the diffuse type of non-Hodgkin's lymphomas; no follicular (germinal center) lymphomas were observed. Three histological patterns comparable to extraneural lymphomas were distinguished: Immunoblastoma (reticulosarcoma) occurred most frequently (58.8%), lympho-plasmacytoid immunocytoma constituted 28 percent, while lymphoblastic lymphoma occurred least frequently (13.2%). There were no significant differences with regard to onset, location, growth pattern or clinical course except for a much poorer prognosis of lymphoblastic lymphoma. Although there are no definite cytological differences between malignant lymphomas arising in extraneural sites or as primary lesions in the CNS, the latter showed a much greater proportion of phagocyting histiocytes (and microglia) and a frequent occurrence of plasmacytes and their precursors which apparently exceded pure host reaction. The prognostic value of modern classification schemes for CNS lymphomas needs further critical evaluation.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001479:Basal Ganglia / Q000473:pathology; D001932:Brain Neoplasms / Q000175:diagnosis / Q000473:pathology; D002493:Central Nervous System Diseases / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D003581:Cytodiagnosis; D005260:Female; D006689:Hodgkin Disease / Q000473:pathology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016403:Lymphoma, Large B-Cell, Diffuse / Q000473:pathology; D008228:Lymphoma, Non-Hodgkin / Q000473:pathology; D008297:Male; D008578:Meninges / Q000473:pathology; D008875:Middle Aged; D009362:Neoplasm Metastasis; D010954:Plasmacytoma / Q000473:pathology; D011379:Prognosis