Acquired pulmonary alveolar proteinosis after umbilical cord blood transplantation for acute myeloid leukemia

Pulmonary alveolar proteinosis (PAP) is a heterogeneous disease that occasionally develops with hematological malignancy. However, PAP in association with hematopoietic stem cell transplantation is quite rare. Here we present the first report of a patient who developed PAP after cord blood transplantation (CBT). A 45‐year‐old female with AML underwent unrelated CBT. On day +2 after CBT she developed congestive heart failure with diffuse alveolar infiltrates in the bilateral lungs. Despite treatment, the alveolar infiltrates further increased with progression of multiple organ failure (MOF). She died from MOF before hematopoietic recovery on day +27. Post‐mortem study revealed that massive amorphous materials positive for periodic acid‐Schiff stain filled in the pulmonary alveoli. These findings led to a diagnosis of PAP. The bone marrow was hypocellular without the leukemic cells. The impaired immunity during the period of leukopenia as well as the impaired clearance of surfactant proteins might contribute to the development of PAP. Am. J. Hematol. 70:154–157, 2002.© 2002 Wiley‐Liss, Inc.