<prompt> Suggested criteria for the clinical diagnosis of Polycythemia vera PV include all except -Low aerial oxygen saturationElevated red cell massIncreased counts of cells of all lineagesSplenomegaly  <response>: In polycythemia vera,erythrocytosis occurs,so red cell mass increases. It is characterised by pancytosisincreased red cells,granulocytes,platelet.Splenomegaly producing abdominal fullness will be also present.There is increased aerial oxygen saturation in polycythemia vera.Reference :Harsh mohan textbook of pathology sixth edition pg no 359. 