Intravascular Large B-Cell Lymphoma of the Kidney

Intravascular large B-cell lymphoma (IVLBCL) is a rare and aggressive non-Hodgkin lymphoma with a nonspecific protean clinical phenotype; therefore its diagnosis can be missed or delayed until tissue sampling. This disease has been recognized by the 2008 World Health Organization Classification of Tumors of Hematopoietic and Lymphoid Tissues, and has previously been termed angiotropic large cell lymphoma, intravascular lymphomatosis, and malignant angioendotheliomatosis.1 An incidence of 0.095 per 1,000,000 in the United States has been reported, with increasing incidence from 2000 to 2013 likely ascribable to increased recognition.2 Tissue damage and the clinical phenotype are likely related to occlusion of the vasculature by the intraluminally sequestered neoplastic cells. We describe a patient who presented with a protracted course of a combination of constitutional symptoms, neurological abnormalities, and splenomegaly, but initially without a clear underlying etiology to explain the clinical findings. Only after significant worsening of proteinuria and hematuria (which was confounded by a recent ureteral stone removal), and the new finding of granular casts and white blood cell casts on urine microscopy, was a kidney biopsy performed, the diagnosis of IVLBCL made, and therapy initiated, thereby illustrating the need for consideration of this neoplasm in the differential diagnosis of acute kidney failure in patients with a constellation of symptoms, and the importance of tissue sampling for diagnosis.