[Diagnosis and treatment of primary thrombocythemia].

Primary thrombocythemia is a frequent myeloproliferative disorder that may be asymptomatic for a long period of time. Once the usual reactive causes have been excluded, further diagnosis requires specialized exploration. The severity level of the disease is not necessarily related to reduce survival rates, but to thrombotic or hemorrhagic complications that can affect quality of life. Myelofibrotic and acute leukemic transformations can also be long-term complications, possibly influenced by treatment strategy. Cytoreductive treatment is required in patients older than 60, or with a history of thrombosis or hemorrhage, or with a platelet count above 1 500 - 109/L. In cases where these indicators do not exist, there are no guidelines for treatment in France, and all investigators try to discriminate patients with a low vascular risk in order to avoid cytoreductive treatment. In fact, in the absence of curative treatment, it seems reasonable to avoid potentially leukemogenic drugs in younger patients.