Autonomous erythropoietin induced erythrocytosis.

Erythrocytosis in a young Sinhalese man is described. The patient was known to have had a raised Hb and PCV for at least 10 years. Subsequent investigations failed to support the diagnosis of polycythaemia vera or to reveal a cause for secondary polycythaemia. Blood erythropoietin values were raised, but no cause for inappropriate secretion could be identified. Although there was no evidence of erythrocytosis in the family, the findings in this patient appear to be those of a condition which has been called familial polycythaemia. The spleen was unusually large and was associated with hypersplenism and thrombocytopenia. Problems of diagnosis and management are described. Phlebotomy appears to be the treatment of choice, with a regimen of regular venesection for the control of symptoms due to hyperviscosity and vascular occlusion.