LAUSR

Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia defined by a balanced translocation between chromosomes 15 and 17 resulting in fusion of the promyelocytic leukemia gene (PML) on chromosome 15 with the retinoic acid receptor-alpha gene (RARα) on chromosome 17. APL often presents with pancytopenia and is associated with a life threatening coagulopathy making prompt diagnosis and initiation of therapy critical. We report an unusual case of APL in a 59 year old female without peripheral blood abnormalities or diffuse marrow involvement. Clinical and radiographic findings were initially interpreted as metastatic osseous disease but ultimately found to be APL.