ESSENTIAL THROMBOCYTHEMIA - 35 YEARS OF E XPERIENCE AND A REVIEW OF THE LITERATURE

Essential thrombocythemia (ET) is a clonal myeloproliferative disorder characterized by an uncontroled rise in peripheral blood platelet cou nt. The aim of this report was to determine the clinical and laborator y data of this disease in a 35 years revision. Of the patients with th e diagnosis of ET, we selected those who fulfilled five of the six dia gnostic criteria proposed by the Poli Vera Study Group. We found 14 ca ses (10 female and 4 male) with a median age of 54.5 years (range 29-7 4). The most frequent initial clinical finding was hemorrhage and in f our cases the diagnosis was preoperative. Median platelet count was 1, 355 x 10(9)/L (range 600 to 3,750). One case had iron deficiency which was corrected before ET was diagnosed. None has evolved to acute leuk emia. Initially, most of the cases were treated with busulphan and two received alpha-interferon which was promptly changed to busulphan bec ause of secondary effects. Three patients have died due to hemorrhagic complications and one due to thrombosis. ET has a low frequency in ou r country and must be considered an exclusion diagnosis. Iron deficien cy may mask the diagnosis specially in the cases with a platelet count not very high. Treatment can provide in general a long survival of go od quality of life.