Polycythemia Vera Differential Diagnoses

Updated: Dec 02, 2016
  • Author: Srikanth Nagalla, MBBS, MS, FACP; Chief Editor: Koyamangalath Krishnan, MD, FRCP, FACP  more...
  • Print
DDx

Diagnostic Considerations

Diagnostic laboratory tests have been developed to increase the ability to diagnose primary myeloproliferative diseases (MPDs) and to differentiate them from reactive conditions associated with increased blood cell levels, which can mimic MPDs. Polycythemia is characterized by increased cell counts in all cell lines in the myeloid series (ie, red blood cells, white blood cells [preferentially granulocytes], and platelets). Thus, if red blood cell levels are increased, several conditions must be excluded, including the following:

  • Conditions that increase red blood cells secondary to systemic hypoxia or an artificial condition stimulating erythropoietin secretion in the kidneys
  • Granulocytosis from infections or mobilization by secondary causes, as in leukemoid reactions
  • Thrombocytosis from bleeding and iron deficiency

Once an MPD (Philadelphia chromosome negative [Ph–]) is documented, it must be differentiated from the following conditions, which have manifestations that overlap with polycythemia vera (PV):

Abdulkarim et al studied the long-term rate (15 years) of leukemic transformation (acute myelogenous leukemia [AML]) in 795 unselected patients with Ph– MPD in the regions of Gothenburg, Sweden, and the Côte d'Or, Burgundy, France. [13] Fifty-six patients (7%) with Ph– MPD demonstrated transformation to AML, of whom six had never received cytoreductive agents and two had been exposed to interferon.

The annual rate of AML transformation was 0.38% in patients with PV, 0.37% in those with ET, and 1.09% in individuals with idiopathic myelofibrosis (IMF). [13] The average time from diagnosis to AML transformation was 88 +/- 56 months in the PV patients compared with 76 +/- 57 months in the ET patients and 42 +/- 33 months in those with IMF (significantly shorter than the PV and ET patients), and the investigators noted that it appeared to be a continuous event in all 3 MPDs.

Another finding was that 17 of 18 patients with PV whose condition transformed to AML were females despite the fact that the male-to-female ratio of the entire PV group was 146:171. [13] The other conditions (ET and IMF) showed a slight male preponderance (ET, 1.33; IMF: 1.13). The average survival for the 56 patients with MPD who developed AML did not differ among the 3 diseases (4.6 +/- 5.5 months). [13]

Differential Diagnoses