Case Report Relapsed Acute Lymphoblastic Leukemia Presenting as Acute Renal Failure Ashley Rose , 1 Samuel Slone, 1 and Eric Padron 2 1 Internal Medicine, University of South Florida, Tampa, FL 33602, USA 2 Malignant Hematology, H. Lee Moftt Cancer Center and Research Institute, Tampa, FL 33602, USA Correspondence should be addressed to Ashley Rose; ashleyrose2@health.usf.edu Received 23 March 2019; Accepted 7 May 2019; Published 13 May 2019 Academic Editor: Yoshihide Fujigaki Copyright © 2019 Ashley Rose et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Acute lymphoblastic leukemia (ALL) is the second most common acute leukemia in adults. It is an aggressive hematologic neoplasm, with a bimodal age distribution typically presenting in childhood and the 6 th decade of life (Terwilliger and Abdul- Hay, 2017). Renal injury in ALL is common and can occur through many diferent mechanisms, such as prerenal acute kidney injury, acute tubular necrosis, renovascular disease, obstruction, glomerulonephritis, and parenchymal infltration of tumor cells (Luciano and Brewster, 2014). Infltration of kidneys by leukemia cells is common; however a resultant injury only occurs in about 1% of patients, and renal failure is even more rare (Luciano and Brewster, 2014). Renal failure due to bilateral infltration of tumor cells has been reported in only a few cases and is thought to be a poor prognostic indicator (Luciano and Brewster, 2014; Sherief et al., 2015). Biopsy is essential to the diagnosis of renal infltration of leukemia. We present a case of acute renal failure secondary to bilateral renal infltration of ALL presenting as the frst sign of relapse in a young man. 1. Introduction Acute lymphoblastic leukemia (ALL) is the second most com- mon acute leukemia in adults with 75% of cases developing from hematopoietic precursors of B-cell lineage [1]. Kidney involvement and injury in leukemia can occur in a variety of diferent ways such as prerenal acute kidney injury (AKI), acute tubular necrosis (ATN), parenchymal infltration by the tumor cells, renovascular diseases, obstruction, glomeru- lonephritis, and electrolyte/acid-base disturbances [2]. AKI secondary to infltration of ALL is rare, with renal failure being even more rare [2]. Te following is a case of acute renal failure secondary to difuse renal involvement by B- cell ALL as the frst sign of relapse, successfully treated with immunotherapy and steroids. 2. Case Presentation A 37-year-old Hispanic male with a history of B-cell acute lymphocytic leukemia (ALL) presented to the emergency department with lef sided fank pain and hematuria. He was previously treated with multiple lines of therapy including several chemotherapy regimens with relapsed/refractory dis- ease. He underwent CAR-T cell therapy in April 2017 and achieved complete remission. He went on to have a mis- matched allogeneic hematopoietic stem cell transplant in August 2017 which was complicated by E. coli bacteremia and BK cystitis induced hematuria. Soon afer, he presented to clinic with acute renal failure and had a ureteral stent placed for lef hydronephrosis. Imaging at that time showed symmetric enlargement and decreased density of the kidneys. Serum BK/adenovirus studies were negative. Urine cytology showed benign urothelial cells. Repeat bone marrow biopsy at that time showed 80% cellularity with 80% lymphoblasts. Te patient was started on Inotuzumab in March 2018. Repeat bone marrow biopsy following cycle 1 showed no evidence of residual B-cell ALL. Te patient then presented to the emergency department in May 2018 with lef sided fank pain and hematuria. Labora- tory analysis demonstrated creatinine of 3.9 mg/dL compared to a baseline of 0.6-0.9 mg/dL just 2 weeks earlier. Urinalysis showed negative nitrites, negative leukocyte esterase, >500 protein, 6-10 WBC, 3-5 RBC, and few granular and hyaline casts. Imaging at that time was unchanged from prior Hindawi Case Reports in Nephrology Volume 2019, Article ID 7913027, 3 pages https://doi.org/10.1155/2019/7913027