Abstract: FR-PO1274
Intravascular Large B-Cell Lymphoma Emerging After Adult-Onset Still Disease and Atypical Crescentic Glomerulonephritis
Session Information
- Onconephrology: Diagnostic Dilemmas, Therapy-Related Toxicities, and Clinical Cases
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Onconephrology
- 1600 Onconephrology
Author
- Miyata, Hitomi, Kyoto Katsura Byoin, Kyoto, Kyoto Prefecture, Japan
Introduction
Intravascular large B cell lymphoma (IVLBCL) is a rare lymphoma characterized by selective proliferation of malignant B cells within small vessels. Because of its diverse manifestations, it often mimics systemic inflammatory diseases, leading to diagnostic delay. Renal involvement is uncommon, and presentation as ANCA negative crescentic glomerulonephritis (GN) is exceptionally rare. We report a diagnostically challenging case that evolved over several years from adult onset Still disease (AOSD) to crescentic GN and ultimately to severe capillary leak syndrome before IVLBCL was confirmed by bone marrow and skin biopsy.
Case Description
A 63-year-old man was diagnosed with AOSD based on fever, arthralgia, liver dysfunction, and elevated inflammatory markers. Bone marrow examination showed no evidence of hematologic malignancy, and he responded well to corticosteroids.
During steroid tapering two years later, he developed acute kidney injury. Kidney biopsy revealed ANCA-negative crescentic GN. Immunofluorescence was negative, but electron microscopy demonstrated electron-dense deposits, suggesting crescentic IgA nephropathy. Steroid therapy led to rapid renal improvement.
Several years after this episode, he was admitted with rapidly worsening edema, hypotension, and acute kidney injury. Urinalysis showed no proteinuria, while laboratory evaluation demonstrated profound hypoalbuminemia, pancytopenia, and markedly elevated LDH, consistent with severe capillary leak. Given the combination of prior crescentic GN, vascular leak, cytopenias, and high LDH, an underlying hematologic disorder was reconsidered. Bone marrow and random skin biopsy were performed, and concordant findings established the diagnosis of IVLBCL. Steroids and chemotherapy led to marked clinical improvement.
Discussion
This case illustrates that IVLBCL can present with features initially attributed to systemic inflammatory diseases or primary glomerular disorders. In patients with ANCA negative crescentic GN accompanied by cytopenias, high LDH, and severe hypoalbuminemia without proteinuria, an underlying hematologic disorder may merit consideration. Bone marrow and skin biopsy may assist in identifying otherwise occult lymphoid malignancy. Awareness of this possibility may help clinicians recognize hematologic disease in atypical crescentic GN.
Acknowledgment
I would like to express our sincere gratitude to Dr. Masakatsu Hishizawa (Department of Hematology) and Dr. Kenichiro Kubo (Division of Rheumatology) for their expert evaluation and dedicated clinical support throughout the diagnostic process of this case. Their thoughtful insights and collaborative care greatly contributed to the timely identification and management of IVLBCL.