<prompt> A 5-year-old boy brought to the OPD by his Father. He is having complains of loss of appetite, fatigue, malaise, intermittent low grade fever. He also complains bone pain, bruising, oral gum bleeding. On examination Lymph nodes are palpable, spleen is also palpable. Lab investigation reveals TLC of 9,000uL with a hemoglobin of 5 gdL and a platelet count of 9,000uL. What is the next investigation for diagnosis?Serum haptoglobinBone marrow biopsyAntiplatelet antibody assayReticulocyte count  <response>: Above sign and symptoms and lab finding give us a probable diagnosis of Acute Lymphoblastic Leukaemia Next best investigation to confirm the diagnosis is Bone Marrow Biopsy Clinical features:- Anorexia, fatigue, malaise, irritability, and intermittent low-grade fever Bone or joint pain, Infection Symptoms of bone marrow failure:- pallor, fatigue, exercise intolerance, bruising, oral mucosal bleeding or epistaxis Lymphadenopathy, hepatosplenomegaly. Diagnosis BM aspirate 20 Leukemic lymphoblasta Immunophenotype : Pre BBT cell Treatment Induction :Vincristine, Anthracycline, Prednisolone, L-Asparaginase CNS prophylaxis : intrathecal methotrexate Intesification : methotrexate, L-Asparaginase , Cyclophosphamide Maintenance phase : 2 -2.5 yrs : oral 6-MP and methotrexate 