polycythemia rubra vera (PV) [Gk, polys, many, kytos, cell, haima, blood; L, ruber, red, verus, true] , a myeloproliferative neoplasm characterized by an elevation in the red blood cell count, hematocrit, hemoglobin level, and number of leukocytes and by thrombocytosis. The skin and mucous membranes acquire a maroon or plum color, and hepatomegaly, splenomegaly, hypertension, and neurological symptoms develop. The condition is associated with the JAK2 mutation. Also called primary polycythemia.
