title: [Erythrocytosis in a 4 year-old child: diagnostic, prognostic, therapeutical problems].
abstract: BACKGROUND
  Pure erythrocytosis is rare in children. This report describes such a case.
  
  
  METHODS
  A 4 year-old boy was admitted because erythrocytosis had been found routinely before adenoidectomy. He was born in Guatemala, was adopted just after his birth, and had been living in France since that age. Clinical examination was normal. His hemogram showed: erythrocytes: 8,800,000/mm3; hemoglobin: 20.1 g/dl; hematocrit: 66.8%; reticulocytes: 262,000/mm3; platelets: 200,000/mm3; leukocytes: 6,800/mm3. The patient had been given iron salts for the past 3 months without an earlier hemogram. Total red cell mass was 1200 ml (N: 600). The myelogram was normal as was the leukocyte alkaline phosphatases, serum lysozyme and vitamin B12. Blood ferritin was low (3.5 ng/ml). In vitro cultures of erythroid precursors were normal, as was the karyotype of myeloid cells. Blood erythropoietin concentration was 20-293 mU/ml (N:4-14). All the causes of secondary polycythemia were eliminated by appropriate investigations. The patient was treated by phlebotomy in aliquots of 25 ml/kg, twice a month, for 10 months, and was given iron therapy. At the end of treatment, his hemoglobin was 14 g/dl and his hematocrit was 45%. Both progressively increased again one year later, requiring new phlebotomies. The patient was followed for 4 years but no cause for this erythrocytosis was found; it was probably congenital in origin.
  
  
  CONCLUSIONS
  This case of pure erythrocytosis was associated with elevated erythropoietin production. Whether this high secretion is related to receptor dysfunction remains to be determined.
authors.affiliation: Service de pédiatrie, hôpital intercommunal, Créteil, France.
authors.forename: A
authors.initials: A
authors.lastname: Zelinsky-Gurung
authors.forename: F
authors.initials: F
authors.lastname: Bernaudin
authors.forename: G
authors.initials: G
authors.lastname: Tchernia
authors.forename: N
authors.initials: N
authors.lastname: Casadevall
authors.forename: S
authors.initials: S
authors.lastname: Lemerle
authors.forename: P
authors.initials: P
authors.lastname: Reinert
mesh_terms: D001815:Bloodletting; D002675:Child, Preschool; D004921:Erythropoietin / Q000097:blood; D006801:Humans; D008297:Male; D011086:Polycythemia / Q000097:blood / Q000175:diagnosis* / Q000628:therapy*; D011379:Prognosis
chemical_list: D004921:Erythropoietin
vernacular_title: Erythrocytose pure chez un enfant de 4 ans: problèmes diagnostiques, pronostiques, thérapeutiques.