Background: Von Willebrand disease is the most common human inherited bleeding disorder. A major challenge for affected patients is achieving an accurate and timely diagnosis. We reported 3 cases of von Willebrand disease diagnosed with different contexts. Case report: Case 1: male, 2.5 months old, whose grandfather and aunt have a bleeding disorder. Hospitalized with purpura and ecchymosis. Was diagnosed with VWD type 1 and monitored at home when bleeding. Case 2: male, 13 years old, diagnosed with Hemophilia A from 2 years old. Unresponsive to treatment, bleeding of the skin and mucosa. Diagnosis of VWD type 1. Treating with cryoprecipitate and oral minirin, the frequency of hospitalization is reduced and well-response. Case 3: female, 9 years old, hospitalized because of a centipede bite. After 4 days, the skin was bleeding with purpura and ecchymosis, and the laboratory showed prolonged APTT and decreased VWF antigen. Diagnosis of acquired VWD after a centipede bite. After 1 month of follow-up, the child did not bleed, and the test returned to normal. Conclusion: The cases described above help to generalize the different diagnostic contexts. The suggestion of VWD is raised when there is a mismatch between clinical and general coagulation tests. A definitive diagnosis of VWD requires a VWF test. Key words: von Willebrand disease, Bleeding disorder, von Willebrand factor

Background: Acute leukemia is the most common malignant disease in children. Patient typically die for complications, there occur as a consequence of treatment and the disease itself. Objectives: To describe the rate and the clinical, paraclinical features of common complications in acute leukemia patients before and during induction therapy. Subjects & methods: A survey was conducted with 34 acute leukemia patients at The Pediatric Center in Hue Central Hospital from 4/2017 to 7/2018. Results: Infection were the most common complication as a percentage of 91.2%, the propotion of severe anemia and severe hemorrhage were at 85.3% and 35.3%. Conclusions: The percentage of infection, severe anemia and severe hemorrhage decreased in period of the last 2 weeks of induction therapy, in which the proportion of severe anemia declined significantly in statistics. Neutrophil counts, platelet counts and hemoglobin levels were significantly increased when patients entered to the last 2 weeks of induction therapy. Key words: complication, acute leukemia, induction therapy