Intravascular Large B-Cell Lymphoma Diagnosed After Recurrent Stroke: Case Report and Literature Review.

Background/Objectives: We describe a case of intravascular large B-cell lymphoma (IVLBCL) presenting with recurrent cerebral infarctions and review similar reported cases. Our aim is to explore potential early diagnostic markers and discuss their prognostic implications. Methods/Results: A 79-year-old man with a history of hypertension, hyperuricemia, and postoperative bladder cancer presented with five to six cerebral infarctions over an 11-month period, despite successive changes in antiplatelet and anticoagulant medications. Neurological examination revealed decreased pain sensation, bilateral hearing loss, and right thenar atrophy. Laboratory studies showed elevated inflammatory markers and soluble IL-2 receptor. CSF analysis revealed elevated protein, β2-microglobulin, IL-6, and IL-10 levels. A skin biopsy was performed to investigate suspected IVLBCL. Histopathological examination of the skin biopsy revealed large pleomorphic CD20-positive cells within the vasculature, confirming a diagnosis of IVLBCL. The patient was treated with chemotherapy, including dose-adjusted R-CHOP and high-dose methotrexate, and achieved complete remission. No recurrence of cerebral infarction was observed during a two-year follow-up period. Conclusions: This case highlights the importance of considering IVLBCL in patients with recurrent strokes of unknown etiology, especially when laboratory or imaging findings suggest systemic involvement. Early recognition and appropriate tissue diagnosis, such as skin biopsy, are essential for timely treatment and favorable prognosis.