Acute Lymphoblastic Leukemia

A 3-year-old girl, previously well, presented with a history of fever reaching up to 103 ° F for 5 days with body aches, but without any localizing symptoms. Her appetite had reduced, but her urine output was normal. There was no history of fever in her family or among her schoolmates. Past medical or surgical conditions were unremarkable. Her vaccinations were up to date. On physical examination, the patient was febrile and conscious, but lethargic. There were no skin rashes, lymph node enlargement, joint swelling, or deformity. Systemic examination was normal. The initial possibilities considered in this child were dengue fever and enteric fever. She was investigated accordingly. The complete blood count (CBC) done showed a hemoglobin (Hb) level of 10.5 g/dL, TC 5800 cells/cmm, DC P23, L 71, and platelet count 84,000/cmm. Dengue NS1 Ag was negative, but the IgM antibody by ELISA was positive. Blood and urine cultures were negative. A diagnosis of dengue fever without warning signs was made. Her fever subsided on the sixth day, her vital signs were normal, but she remained lethargic. The parents were asked to return if there were any new symptoms or her lethargy persisted. The child was brought back after 4 days. There was no fever, but she continued to complain of leg pain and was sometimes waking up at night crying with pain. On examination, she was afebrile, pale, and had tenderness over both her legs. Systemic examination continued to remain normal. Her complete blood count was repeated along with serum lactate dehydrogenase (LDH) levels. Laboratory investigations revealed Hb 9.8 g/dL, TC 7800 cells/cmm, DC P23, L 71, and a platelet count of 78,000/cmm. Peripheral smear examination was also reported to be normal. Because of persistent thrombocytopenia, serum LDH was examined and found to be 378 U/L (ref. range: upper limit 235 U/L). Because of the clinical feature with increased serum LDH levels, the possibility of acute leukemia was considered. The bone marrow examination revealed numerous blast cells. A diagnosis of acute lymphoblastic leukemia was made. The child was referred to the pediatric hemato-oncology unit for further evaluation and management. She was stratified as standard risk after evaluation and treated accordingly. She has tolerated the treatment and responded well to chemotherapy.