Congenital erythrocytosis with increased erythropoietin level

The term "absolute erythrocytosis" denotes a heterogeneous group of disorders characterized by an increased red blood cell mass. The authors describe a 20-month-old girl with absolute erythrocytosis. Erythropoietin levels were found to be extremely increased, although extensive evaluation failed to reveal a cause for such an inappropriate increase. Of interest is also the documentation of spontaneous erythroid colony formation in the patient's bone marrow cultures. Although such a finding is considered typical of polycythemia vera, the diagnostic criteria of this myeloproliferative disorder were not met.