Acute myeloid leukemia with leukemic pleural effusion.

Acute myeloid leukemia (AML) may be associated with extramedullary tumor growth, which is commonly known as myeloid sarcoma. Although AML with leukemic pleural effusion is considered rare, the true incidence is not clear. We report three cases of AML involving pleural effusion in this study. The cases were encountered in a single institute within two years, suggesting that leukemic effusion is more common than previously reported. Leukemic cells showed evidence of monocytic differentiation in all cases. Two patients presented with advanced AML. Both had concurrent myeloid sarcoma. Both were ineligible for intensive treatment and died soon after diagnosis of myeloid sarcoma. The third patient had pleural effusion upon diagnosis of AML. Remission was achieved and the effusion disappeared after treatment. We conclude leukemic effusion may become more common in an era of improved care and prolonged survival for AML patients. The prognostic impact is unclear and patients should be given standard AML treatment whenever possible.