Spontaneous Resolution of Myelofibrosis and Pancytopenia Followed by the Development of Acute Myeloid Leukemia With an Extramedullary Mass

PURPOSE: Spontaneous resolution of myelofibrosis is extremely rare. A patient with myelofibrosis and pancytopenia that spontaneously resolved with subsequent development of acute myelomonocytic leukemia and an extramedullary mass of the ovary is described. PATIENT AND METHODS: A 2-year-old girl had severe pancytopenia and myelofibrosis without signs of myeloid metaplasia. The patient was transfused with packed red blood cells and platelets and monitored. RESULTS: The pancytopenia and myelofibrosis resolved spontaneously within 1 month after initial presentation and her blood counts normalized. The patient developed a chloroma of the ovary and acute myelomonocytic leukemia 13 months later and eventually died from disease. CONCLUSIONS: This patient initially had acute myelofibrosis which was most likely secondary to occult acute myelomonocytic leukemia. The transfusions may have been a contributing factor in the spontaneous remission.