Leukostasis followed by hemorrhage complicating the initiation of chemotherapy in patients with acute myeloid leukemia and hyperleukocytosis: a clinicopathologic report of four cases.

Abstract

Pulmonary and cerebral leukostasis, or parenchymal hemorrhage in these organs, are well-known early complications developing in patients with acute myeloid leukemia (AML), particularly when myelomonocytic features, hyperleukocytosis, and/or a coagulation disorder are initially present. Commonly, these complications arise during increasing leukocyte counts (WBCs). The authors describe four patients with AML and hyperleukocytosis who developed leukostasis followed by parenchymal hemorrhage. Bleeding in all patients occurred while their WBCs were decreasing following cytosine-arabinoside chemotherapy, and in the absence of disseminated intravascular coagulation or severe thrombocytopenia. Radiologic and histopathologic findings underscoring possible mechanisms are presented in the article. Alterations of cell adhesion associated with chemotherapy-induced blast lysis or cellular differentiation are possible factors contributing to this particular sequence (cytosine arabinoside-based chemotherapy, leukostasis, and subsequent hemorrhage). Prophylactic measures for managing this early complication of AML treatment include leukapheresis to reduce the WBC prior to the initiation of chemotherapy.