Bleeding and thrombosis in hematologic neoplasia

Excessive bleeding or thrombosis complicates the treatment of many patients with hematologic malignancies. The pathogenesis and therapy of some of these disorders, such as thrombocytopenia due to invasion of the marrow by tumor cells or chemotherapy, is usually straightforward. However, other hemostatic defects are more complex. For example: 1. Malignant cells can produce and release thromboplastic or fibrinolytic substances that cause disseminated intravascular coagulation (DIC) or primary fibrinolysis (for example, acute promyelocytic leukemia) (APL). 2. The pathologic process can provoke the megakaryocyte to produce dysfunctional platelets with bleeding or thrombosis (chronic myeloproliferative disorders). 3. Abnormal lymphocytes or plasma cells sometimes produce aberrant proteins that interfere with normal hemostasis (multiple myeloma, amyloid). 4. Certain antitumor or antimicrobial agents used in the treatment of malignancy or its complications can cause thrombosis or bleeding (1-asparaginase or some β-lactam antibiotics). This chapter focuses on bleeding and thrombotic disorders that are associated with hematologic neoplasia. Thrombocytopenic bleeding and of platelet transfusion therapy is covered elsewhere in this volume.