Abstract: FR-PO1249
Isolated Renal Relapse of B-Cell Acute Lymphoblastic Leukemia (B-ALL): Kidney Biopsy as a Key Diagnostic Tool
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
Authors
- Herman, Paige E., VCU Health System, Richmond, Virginia, United States
- Patrick, Kennerly Clinton, VCU Health System, Richmond, Virginia, United States
Introduction
Renal involvement in acute lymphoblastic leukemia (ALL) is well described at autopsy, with leukemic infiltration of the kidneys reported in ~54% of cases, compared to 60-90% of all patients with hematologic malignancies. Most patients with renal infiltration do not develop overt acute kidney injury (AKI), and AKI attributable to renal infiltration is seen in only 1% of leukemias and <1% of lymphomas. Extramedullary relapse with normal peripheral blood counts and an unremarkable bone marrow is rare, poses a significant diagnostic challenge and may delay initiation of salvage therapy. We describe a case in which renal biopsy was performed for evaluation of progressive AKI and established the diagnosis of relapsed B-ALL.
Case Description
A 67-year-old male with hypertension and no known renal disease presented with dyspnea and lower extremity edema, found to have stage 3 AKI requiring dialysis. Renal biopsy revealed leukemic infiltrate, establishing a new diagnosis of B-ALL. He was treated with mini-CVAD, inotuzumab, and blinatumomab, with sufficient renal recovery to discontinue dialysis. He underwent allogeneic HSCT approximately one year after diagnosis, achieving full remission by bone marrow biopsy and negative measurable residual disease (MRD) testing, though with persistent CKD3b. Two years post-HSCT, asymptomatic rise in serum creatinine (sCr, mg/dL) from ~2.5 to ~3.5 prompted concern for relapse; however, repeat marrow and peripheral counts were normal. Kidney biopsy was performed and demonstrated diffuse parenchymal effacement by a monotonous population of medium-sized cells with fine chromatin and scant cytoplasm in sheets and nests, and immunohistochemistry staining all consistent with B-ALL. Bone marrow flow cytometry subsequently identified a suspicious immature B-cell population. sCr peaked at 5.2 mg/dL while awaiting workup; reinduction chemotherapy was initiated, with improvement in sCr to 2.9 mg/dL with CAR-T cell therapy under consideration.
Discussion
Although leukemic renal infiltration is common in hematologic malignancies, clinically significant AKI due to direct infiltration is rare. Isolated renal relapse without hematologic or bone marrow involvement is even more rare. Recurrent ALL may evade routine surveillance in these patients, and kidney biopsy is crucial for prompt diagnosis and re-initiation of therapy.