We report an unusual lethal complication of sickle cell anemia. The patient
was admitted with a diagnosis of acute chest syndrome and died shortly aft
er that of respiratory failure. Autopsy revealed numerous deposits of bone
marrow hematopoietic tissue occluding the microvascular circulation of the
lung. Many causes of acute chest syndrome in sickle cell anemia have been i
dentified, including bone marrow infarction leading to embolism of bone mar
row fat. However, the release of bone marrow hematopoietic tissue leading t
o pulmonary vascular occlusion is not generally recognized premortem by tre
ating physicians.