Recurrent Gastrointestinal Hemorrhage in Treatment with Dasatinib in a Patient Showing SMAD4 Mutation with Acute Lymphoblastic Leukemia Philadelphia Positive and Juvenile Polyposis Hereditary Hemorrhagic Telangiectasia Syndrome

We report a case of a patient affected by juvenile polyposis and hereditary hemorrhagic telangiectasia linked to a SMAD4 mutation who developed acute lymphoblastic leukemia positive for the Philadelphia chromosome translocation and with a complex karyotype. During the treatment with the tyrosine kinase inhibitor dasatinib the patient presented recurrent severe gastrointestinal hemorrhages linked to the genetic background and aggravated by thrombocytopenia.