eng Science and Education Publishing American Journal of Medical Case Reports 2374-216X 2024-09-26 12 9 141 143 10.12691/ajmcr-12-9-3 AJMCR20241293 article Sikander Chohan ga7975@wayne.edu 1 Shahina Patel 2 Wayne State University School of Medicine, Detroit, MI, USA Henry Ford Hospital, Wyandotte, MI, USA Intravascular large B-cell lymphoma (IVLBCL) is a form of diffuse large B-cell lymphoma (DLBCL) characterized by the proliferation of malignant B-cells within the lumen of small blood vessels. With an incidence rate of one in a million, it is one of the rarest forms of DLBCL. This rarity, combined with the absence of extravascular tumor masses or circulating malignant cells in the peripheral blood and potential involvement of multiple organs, makes the diagnosis of IVLBCL exceptionally difficult. We discuss that case of a 64-year-old female who presented with symptoms of altered mental status, expressive aphasia, and fatigue. She was also found to have normocytic anemia with elevated hemolysis markers. Over a period of months, her neurological symptoms and anemia with elevated hemolysis markers persisted despite repeated hematological, infectious, and neurological workup. Overall, we hope to highlight the unusual clinical manifestations of IVLBCL, as early diagnosis and treatment can be lifesaving. https://pubs.sciepub.com/ajmcr/12/9/3/ajmcr-12-9-3.pdf lymphoma B-cell hematological malignancy oncology renal malignancy