Multiple Organ Failure Due to Leukostasis Caused by Rapidly Progressive Hyperleukocytosis: A Case Report.

Myelodysplastic syndrome (MDS) is common in older adults and progresses to acute myeloid leukemia (AML) with a poor prognosis. Here, we present the case of a 71-year-old man undergoing treatment for MDS who was brought to the hospital for emergency care after suddenly becoming disoriented while on a trip. Laboratory results revealed a markedly increased white blood cell count (468,480/μL) with a predominance of blast cells (89%), and he was diagnosed with hyperleukocytosis (HL) and leukostasis associated with acute conversion to AML (probably M4). After surviving two cardiac arrests, the patient was deemed not strong enough to survive another cardiopulmonary arrest. A decision was made to withdraw from invasive treatment in the acute phase, and the patient died within eight hours of arrival at the hospital. It is challenging to determine whether the cause of vascular occlusion is a thrombus or a blast cell. Generally, when leukostasis is associated with HL and monocyte proliferation, occlusion by blast cells is the most common cause. Leukostasis is caused by the adhesion of intravascular blast cells and increased blood viscosity and is fatal, particularly in the respiratory and central nervous systems. Treatments include hydroxyurea/low-dose chemotherapy and leukapheresis; however, evidence of their ability to improve early mortality is lacking. In older patients, family opinion plays a vital role in treatment decisions, and collaboration with hematologists is essential.