Simultaneous occurrence of atypical hemolytic uremic syndrome and acute lymphoblastic leukemia: a case report and literature review

A 3.5-year-old girl with fever had a pancytopenic blood smear that also showed schistocytes and blast cells. Bone marrow examination resulted in a diagnosis of acute lymphoblastic leukemia (ALL). Although creatinine on admission was normal, she had mild hematuria and moderate proteinuria. Chemotherapy was started, but she was initially given only steroids (dexamethasone) due to high liver enzymes. Her renal parameters worsened, and her creatinine doubled. She also developed nephrotic-range proteinuria and hypertension. Renal biopsy showed thrombotic microangiopathy that was clinically consistent with hemolytic uremic syndrome (HUS). Some reports of HUS preceding ALL do exist. However, to the best of our knowledge, this is the first case that describes ALL and HUS presenting simultaneously.