Polycythemia vera in childhood: case report and review of the literature.

A patient presented at 5 years of age with polycythemia vera. He subsequently developed splenic infarctions and died at 20 years of age following cerebral hemorrhage and infarctions. Two months before his death, he developed hypertension and had biochemical evidence of primary hyperparathyroidism and possibly pheochromocytoma. Only nine reported childhood cases of polycythemia vera fulfill the criteria of the Polycythemia Vera Study Group. These cases are summarized and the complications discussed. Although none have progressed to myeloid metaplasia or acute leukemia, these patients are at risk of developing thrombo-hemorrhagic complications; available evidence indicates that they should be managed to keep the hematocrit between 40 and 45%.