Malignant angioendotheliomatosis, so called intravascular malignant lymphomatosis or angiotropic lymphoma, was found in cerebral hemispheres, spinal cord and nerve roots of a 50-year-old woman who died 4 months after onset of neurological symptoms. The pathological findings were characterised by neoplastic cells within the lumina and wall of small vessels as well as by multiple infarcts in the CNS. Vascular occlusions were caused by tumor cells and secondary changes of the wall. Positive reactions of Common Leucocyte Antigen and B-cell-markers support the idea of a lymphoid origin for the tumor cells. The differentiation to the angiocentric lymphoma as a T-cell tumor and the obscure pathogenesis of this neoplastic process must be clarified in the future.