Tumor Lysis Syndrome and Hyperleukocytosis in Childhood Acute Lymphoblastic Leukemia in a Tertiary Care Hospital.

Acute lymphoblastic leukemia is the most common (77%) childhood leukemia and also the most common neoplastic disease in children. Acute lymphoblastic leukemia initially present with hyperleukocytosis (WBC count more than 50,000/mm³) in twenty percent cases. These children are particularly at risk of development of tumor lysis syndrome (TLS). Tumor lysis syndrome is a metabolic disorder consists of hyperuricaemia, hyperkalemia, hyperphosphataemia, hypocalcaemia with or without renal insufficiency. It is the most common disease related emergency encountered by physicians caring for cancer of children and adult. This cross sectional observational study was conducted in Department of Paediatric Haemato-oncology, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh from November 2011 to April 2012 and was designed to assess early biochemical changes associated with hyperleukocytosis which may follow tumor lysis syndrome. Children with Acute lymphoblastic leukemia with hyperleukocytosis who are potential to develop tumor lysis syndrome were selected for the study in their initial presentation. Thirty patients with newly diagnosed acute lymphoblastic leukemia with initial high WBC count; more than 50,000/mm³ were selected for the study. The objectives of the study were to observe the development of tumor lysis syndrome with hyperleukocytosis, detection of early signs of electrolyte changes and early detection of tumor lysis syndrome which can help further in the management of such patients. Majority of the cases were in age group 7 years to 15 years with male predominance (83%). Hyperphosphataemia (80%) followed by hyperuricaemia (53%) were the most common biochemical findings. Hyperkalemia and hypocalcaemia were present in 33% and 26% patients. Laboratory tumor lysis syndrome was developed in 40% of patients and clinical tumor lysis syndrome was developed in 20% patients with hyperleucocytosis meeting the criteria for definition of tumor lysis syndrome by Cairo Bishop in 2004. It was observed that TLS increased with higher WBC. Tumor lysis syndrome developed in 26% patients with WBC count below one lac, 50% with WBC count 1 lac to 2 lacs and increasing upto 100% with WBC count more than 3 lacs. Developing tumor lysis syndrome in high LDH (44% when LDH is more than 1000 unit/l) was also observed.