Mast cell leukemia and hemophagocytosis in a patient with myelodysplastic syndrome.

![Figure][1] A 65-year-old woman was diagnosed with myelodysplastic syndrome (MDS) with extra blasts-2 with 10% myeloblasts without any evidence of a mast cell disorder. She received azacitidine without response. Thirteen months after the initial diagnosis, she developed worsening