Abstract:

objective: To summarize and review a child with Juvenile myelomonocytic leukemia(JMML)so as to improve our understanding to the disease. Methods: A case of Juvenile myelomonocytic leukemia Accompanied with Complex clinical manifestations was reported. We summarize the clinical date of the case and give related analysis and literature review for the disease . Results: The children was 2years old, male , onset with anemia, hemorrhage, pulmonary infection . Physical characteristics :The face is pale,we can see scattered milk coffee spot on the body , hepatomegaly, splenomegaly .The laboratory result: Blood tests: WBC: 75.2x109 / L,M: 6.6%, monocytes monocytes absolute value: 4.94x109 / L, RBC1.07x1012 / L HBC 37g / L, MCV 120fl PLT 36x109 / L, Peripheral blood smear can see a large number of immature cells. we try to give him RBC and platelet transfusion therapy to help him against anemia and hemorrhage . but the boy show up difficult to blood group examination ,and subsequently he developed symptoms of hemolytic anemia ,invalid blood transfusion . we give him Antibiotic treatment against infection, blood transfusion support ,and he fell better.then we give him a bone marrow biopsy. Bone marrow cytology: Bone marrow hyperplasia, mononuclear cells occupy 22% of nucleated cells, including the original immature single accounted for about 13% , and the parents refuse hematopoietic stem cell transplantation therapy , He was taken home .then died a month late . literature review show: Abnormal RAS/MAPK signal transduction pathway activation play a key role in the pathogenesis of JMML, Noonan syndrome (NS) and neurofibromatosis type I (NFI), and other genetic developmental disorder in patients with comorbid or significantly increased the risk of secondary JMML. It has been reported in patients with hematologic malignancies appear difficult to blood group examination , It is related to the patient`s bone marrow stem cells hyperproliferative and surface antigens on the red blood cell reduced or changed . and patients with hematologic malignancies present with invalid transfusion is due to infection, immune disorders and autoantibody production in the pathological state .Conclusion: JMM is a malignant hematologic diseases with very low incidence in children , Typical with clonal hematopoietic stem cell disorder in childhood, The average age of onset was 2 years old, and the boys have high incidence .the prognosis is poor, mortality is high, Hematopoietic stem cell transplantation is the only way to cure the majority of children.