Brain Pathology Case of the Month - October 1999


Post-mortem coronal sections of the brain showed multiple small ischemic necroses in the gray and white matter partly confluent to larger areas, especially in the temporal, frontal and occipital lobes. The microscopic examination detected intravascular masses of large round cells with a moderate rim of cytoplasm (Fig. 2), often appearing like a tumor thrombus. These were in both intracerebral, leptomeningeal (Fig. 3), and choroidal vessels (Fig. 4). Immunohistochemically, the tumor cells were positive for the B cell marker L26 (Fig. 4). In all regions of the gray and white matter there were multiple perivascular infarctions in different stages, partly with masses of macrophages (Fig. 5, immunostained with KiM1P), and disseminated small bleedings. Focally, selective neuronal loss was found in different places. Examination of the peripheral organs showed the same vascular changes in the heart, lungs, kidneys, liver and spinal ganglia. The spinal cord was not investigated.


International Society of Neuropathology