Pv is very rare in childhood, only 17 cases have been reported.

Methods: In a retrospective study, we analysed the diagnostic and evolutive characteristics of PV in childhood. We sent a mail to all French Pediatric Hematologic Units and we included in the study all the children registered. One child from Switzerland was added.

Results: Table

Table 1
Full size table

Conclusions: PV is usually suspected fortuitously or in case of hyperviscosity signs, which are almost always present and for a long period of time. Leukocytosis and thrombocytosis seem to be less frequent in childhood than in adults. Only three of six cases met the PVSG criteria. In PV erythroid progenitors grow spontaneously without exogenous EPO, which is necessary in secondary polycythemia. A low or normal level of EPO may be contributive to the diagnosis. Thrombotic and hemorrhagic complications are described in childhood PV, however they seem to be less frequent than in adults. The evolution is seldom known. Bleeding the patient is the usual mode of treatment but, as in adults, an oral continuous chemotherapy with hydroxyurea or pipobroman may be instituted. Long term follow-up is necessary to evaluate relapse rate side-effects of the treatment.