TAM.pdf

Pediatric leukocytosis TAM, JMML, or something else ?  Leukocytosis is defined as an elevated white blood cell (WBC) count for age. leukemoid reaction: WBC count > 50 × 103/μL with neutrophils and immature myeloid forms typically occurring i...

Pediatric leukocytosis TAM, JMML, or something else ?  Leukocytosis is defined as an elevated white blood cell (WBC) count for age. leukemoid reaction: WBC count > 50 × 103/μL with neutrophils and immature myeloid forms typically occurring in the setting of an infection hyperleukocytosis typically refers to a WBC count > 100 × 103/μL. Leukocytosis can be primary disease process or occurs secondary to an identifiable underlying etiology(eg, infection). Date Your Footer Here 2  workup for pediatric patients with leukocytosis Thorough history and physical examination Inflammatory markers, CBC) with differential organ functional and peripheral blood assessment and smear infection screen Additional workup may be required depending on the results of these evaluations and clinical suspicion 3 Case 1 You are consulted by the (NICU) regarding a 5 day old full term infant with trisomy21(T21) found to have leukocytosis on a CBC sent during an infectious workup, the postnatal course has been notable for respiratory distress and a low grade fever prompting the recent infectious workup. Physical examination is notable for stigmata of T21 and hepatomegaly. Review of the patient’s laboratory results reveals leukocytosis with WBC 60.8 × 103 /μL and 40% blasts, with normal hemoglobin and platelet counts. Date Your Footer Here 4 Approaching this patient Fever and leukocytosis with left shift>> Infection. Hx of T21 with increased peripheral blast count>> increased risk of developing myeloproliferative disorders and acute leukemia. Date Your Footer Here 5 Abnormal myelopoiesis in trisomy 21 1- Transient abnormal myelopoiesis (TAM) 2- Myeloid leukemia of Down syndrome (ML-DS) The over all risk of acute leukemia in patients with T21 is 18-fold higher than in the general population. The risk of AML in T21 patients aged