[Cerebral lymphoma in AIDS: clinical study and clinicopathological correlations]

We report the natural history of 17 brain lymphomas (11 primary, 6 disseminated) from a post-mortem series of 130 patients with AIDS. Primary lymphomas appeared lately in the course of AIDS. They were often associated with a severe T-cell immunodepression and with more frequent opportunistic disorders than disseminated lymphomas. Associated Kaposi's sarcomas were surprisingly frequent. All patients presented with neurological manifestations. Heterogeneous features were seen at CT examination. The CSF was abnormal in 12/13 cases, with an increase of protein contents and secretion of immunoglobulins; it contained activated lymphocytes in 5/6 cases of disseminated lymphomas, and malignant cells in only one case. Cellular density never exceeded 8/mm3 for primary lymphomas, and the lymphocytes were considered normal. The pre-mortem diagnosis of cerebral lymphomas was made in five patients, with a time lapse of 1 to 7 months between the first neurological symptoms and death, and of 5 to 30 days between the diagnosis and death. Cerebral biopsy was diagnostic in 4 cases of primary cerebral lymphomas. In only 1/6 patients with disseminated lymphomas, the diagnosis had been made when the patient was still alive, based on CSF and bone marrow lymphomatous infiltrations. The diagnosis of cerebral lymphoma (7 primary, 5 disseminated) was post-mortem in 12 cases. It was made only at microscopic examination in 2/12 cases of primary lymphomas. The histopathological study frequently showed a multicentric involvement, and always an immunoblastic cell type with plasmablastic differentiation and frequent medium size cells. Marked gliosis and significant necrosis were often observed. Neuropathological lesions associated with HIV-1 infection (toxoplasmosis, CMV and HIV-1 encephalitis) were seen in 8 cases with primary lymphomas.