Microcytic polycythemia. Frequency of nonthalassemic causes
J. D. Bessman
A high RBC count combined with a low mean volume generally is attributed to
thalassemia minor, either alpha or beta, or to polycythemia vera with iron
deficiency. Among 330 patients with a mean corpuscular volume (MCV) less
than 70 cumu, 35 had increased RBC counts. Of these, 26 had thalassemia
minor and four had polycythemia vera. Five had secondary polycythemia (four
from hypoxia, one from hypernephroma) with incidental iron deficiency. In
the four of these patients given iron, the RBC count remained above normal
and the MCV rose to normal. The RBC size distribution curves reliably
distinguished between thalassemia minor and polycythemia with iron
deficiency.
