About 500 new cases of acute lymphoblastic leukemia (ALL) are diagnosed annually in Romania in the age group 0–18 years. The Philadelphia chromosome (Ph+) is present in 2–5% of childhood ALL, compared to 25% in adults. The translocation t(9;22) induces the active tyrosine kinase BCR-ABL1 which causes the proliferation of hematopoietic cells in the bone marrow. Ph+ ALL is an agressive leukemia, which appears at older ages, with high leucocyte number, L2 morphology, common-B, pre-B or T-cell immunology, often with pseudodiploid caryotype and which can rapidly become chemoresistant. The prognosis is severe, the survival is 25–32% with chemotherapy alone and 34–48% with hematopoietic stem cell transplantation (HSCT). Survival has improved with chemotherapy associated with tyrosine kinase inhibitor (TKI). The 12-year-old boy was admitted for repeated respiratory infections, pallor, fatigability, abdominal pain. On admission he was pale, with some ecchimoses on the extremities, generalized adenomegaly, hepato-splenomegaly. WBC 380.000/ μL, Hgb 5,4 g/dL, Htc 19,8%, platelets 52.000/μL. In peripheral blood there were 86% lymphoblasts. The bone marrow was infiltrated in proportion of 95% with FAB L2 type, pre-B lymphoblasts, with a ratio of bcr-abl/ abl over 100% IS (Ritus-Biotech, Codlea). The patient underwent high-risk chemotherapy, in association with Imatinib 400 mg/day po for the last 10 months. An invasive fungal infection caused his death, after the last high-risk chemotherapeutic block.
Keywords: Philadelphia chromosome, acute lymphoblastic leukemia, child.