[Secondary polycythemias: the role of erythropoietin].
The discovery of high hemoglobin and hematocrit values in a patient necessitates the determination of the red blood cell mass in order to confirm the absolute character of the polycythemia. If a true polycythemia is confirmed, its etiology must then be established. The diagnostic approach of polycythemia is presented in this paper. It is illustrated by a case presentation in which a polycythemia secondary to a renal carcinoma is discussed. Erythrocytosis is a classical, albeit rare manifestation of this type of tumor, and has the advantage of allowing early detection. Thus, it permits a prompt treatment plan, thereby improving the prognosis of such a neoplasia. The usefulness of a serum level of erythropoietin (EPO) is subsequently discussed. The diagnostic value of EPO remains controversial because of the overlapping values recorded amongst healthy patients, patients with polycythemia vera and others with secondary polycythemia. Finally, we discuss the presence of substances in paraneoplastic polycythemias whose biological activity is close to that of EPO. However, this molecules of a different structure would not be detected by the radioimmunoassay used to measure erythropoietin level.
Rognon
R
R
Département de médecine interne, Unité hospitalière de Neuchâtel, Hôpital des Cadolles.
Piguet
D
D
Mégevand
M
M
Kaeser
P
P
D000465:Algorithms; D002292:Carcinoma, Renal Cell / Q000097:blood*; D003937:Diagnosis, Differential; D004921:Erythropoietin / Q000032:analysis*; D006801:Humans; D007680:Kidney Neoplasms / Q000097:blood*; D008297:Male; D011086:Polycythemia / Q000097:blood* / Q000209:etiology
D004921:Erythropoietin
Polyglobulies secondaires: le rôle de l'érythropoïétine.