Persistence of systemic mastocytosis after allogeneic bone marrow transplantation in spite of complete remission of the associated myelodysplastic syndrome.

A myelodysplastic syndrome (MDS), type 5 (RAEB-t), and systemic mastocytosis affecting the spleen, the splenic lymph nodes, the bone marrow and the liver were diagnosed in a 38-year-old woman. The clinical course was complicated by splenic vein thromboses and iliac artery embolism. The thrombotic episodes might be secondary to mast cell mediator release. A complete remission of the MDS was obtained by allogeneic bone marrow transplantation, but the mastocytosis persisted. Thus, the possibility that the mast cell originates from a common myeloid precursor cell may be questioned.