RESUMEN
BACKGROUND: Acquired idiopathic sideroblastic anemia (AISA) is a heterogeneous condition. Most instances, involving only the erythroid line, are benign disease with a longer survival and a low propensity for evolution into acute leukemia. A subset of patients have severe clinical course and evidence of other cell line involvement at presentation, may develop the emergence of blast cells and evolution into acute leukemia. In an attempt to identify the natural history and the risk factors for the development of acute leukemia, the clinical, hematological and outcome data were studied in the patients with AISA. METHODS: We reviewed retrospectively the medical records of 15 patients of AISA treated at the Catholic University of Taegu-Hyosung and Kyungpook National University Hospital from March 1989 to December 1995. RESULTS: The median age at diagnosis was 41 years and the male to female ratio was 8 : 7. On bone marrow examination, erythroid abnormalities were prominent in all cases, 5 patients also showed involvement of the granulocytic and/or megakaryocytic cell lines (AISA with myelodysplastic features, AISA-M). The median follow-up duration was 32 months. Transfusion dependence occurred in 11 of 16 cases. Progression towards refractory anemia with excess of blasts or acute leukemia (M2) was observed in two patients with AISA-M after follow-up period of 16 months and 24 months, respectively. Infections and hemorrhages were causes of death in 3 patients with AISA-M but not in patients with dyserythropoiesis only (AISA-erythroid, AISA-E). CONCLUSIONS: Most patients with AISA have a relatively benign course with prolonged survival after the onset of anemia. Patients with features of dysgranulopoiesis and/or dysmegakaryopoiesis in addition to dyserythropoiesis at presentation were increased risk of transformation to refractory anemia with excess of blasts or acute leukemia and shorter surtival. But further study of larger numbers of patients and longer follow-up may be warranted.