Congenital dyserythropoietic type II anemia complicated by extramedullary hematopoiesis in the posterior mediastinum

: In a 48-year-old woman investigated on account of congenital dyserythropoietic anaemia type II (HEMPAS) on the X-ray of the chest a polycystic sharply defined shadow in the posterior mediastinum was detected and extramedullary haematopoiesis was suspected. The diagnosis was confirmed cytologically. According to the authors' knowledge this is the second case of this rare complication in CDA-II in the world and the second case of EMH in the mediastinum in this country. In the discussion the authors summarize the diagnostics of congenital dyserythropoietic anaemias. They discuss also the pathogenesis of extramedullary haematopoiesis, diagnosis and differential diagnosis of EMH in the posterior mediastinum, possible complications and treatment.