Preleukemia and urticaria pigmentosa followed by acute myelomonoblastic leukemia

A preleukemic syndrome, mast cell hyperplasia in the bone marrow, and urticaria pigmentosa simultaneously developed in a 76-year-old woman. A year later, the patient died of acute myelomonoblastic leukemia. These associations provide evidence favoring the origin of the tissue mast cell from a bone marrow stem cell.