[Primary intracerebral non-Hodgkin's lymphoma--a clinicopathologic study].

Primary cerebral lymphomas (PCL) were diagnosed with increasing frequency also in our retrospective study of 44 patients. Clinically these tumors presented with signs of a rapidly growing brain neoplasm. The analysis of CCT data showed that the tumors were of varying density before and showed mostly (60%) homogeneous enhancement after contrast medium application. MR imaging was more sensitive, but could not aid in distinguishing PCL from other brain tumors. The lesions lay mainly (82%) in the supratentorial space and involved the frontal lobe in 42% of cases. Only 16% were located in the periventricular region including corpus callosum and basal ganglia. 20% of cases showed multiple lesions. Suspected diagnoses were therefore mainly meningeoma, glioma and metastases. Morphological diagnosis was easily possible with the aid of immunohistological methods: there were 41 B-cell lymphomas (93%), two T-cell lymphomas and one large cell anaplastic lymphoma of the non-B non-T phenotype. An unequivocal correlation between morphology and radiological picture existed in the way that tumors with a dense cellular infiltrate appeared mainly as hyperdense lesions with homogeneous contrast enhancement. The clinical course was characterized by CNS-relapses frequently with multiple cerebral lesions and a spinal recurrence in one case. 7% of cases showed evidence of extracerebral disease in a bone marrow biopsy specimen or at autopsy. The average survival of the patients was 15 months, one year survival was 36%, two year survival 12% and 5% of patients lived for more than 5 years.