An autopsy case of intravascular large B-cell lymphoma showing a rapid transition to embolic strokes with occlusion of the major cerebral arteries.

Intravascular large B-cell lymphoma can induce central nervous system manifestations, including strokes, due to small-vessel occlusion caused by lymphoma cells. However, involvement in large-sized vessels is rare. Here, we present an unusual autopsy case of an 88-year-old man showing a rapid transition from multiple strokes due to small vessel occlusion, typical of intravascular lymphoma, to progressive embolic strokes caused by the occlusion of major cerebral arteries. Magnetic resonance angiography demonstrated the major cerebral arteries associated with those multiple progressive strokes, including the right posterior cerebral artery, left anterior cerebral artery, and right middle cerebral artery, but the detectability was poor. A random skin biopsy at the abdomen confirmed the diagnosis of intravascular large B-cell lymphoma. The patient died 106 days after hospitalization despite intensive treatment. An autopsy revealed broad liquefactive necrosis in the area governed by the major cerebral arteries and multiple small infarctions caused by intravascular lymphoma cells in the small-sized vessels. In addition, the major cerebral arteries showed multiple thromboembolism with partial organization and clusters of intravascular lymphoma cells. Notably, those cells were shown aggregated and attached along the vascular wall of the basilar artery, which might have caused focal hypercoagulation in the near vessels. This aggregation might have disseminated widely in the other major cerebral arteries. Moreover, the cluster of intravascular lymphoma cells in the basilar artery was positive for tumor necrosis factor α, and similar histopathology findings were observed in the splenic veins. However, the pathogenesis of this rare phenomenon involving these cells remains unknown. From a clinical perspective, we should consider the possibility that intravascular lymphoma cells may provoke similar progressive embolic strokes.