Primary thrombocythaemia: diagnosis and management.

Since PT is more likely than reactive thrombocytosis to be complicated by thromboembolic manifestations, the differential diagnosis is important. A combination of positive clinical and laboratory criteria probably represents the most useful diagnostic method at present, although a molecular biological approach may prove to be of value in females in the future. Treatment to suppress the megakaryocytic proliferation is suggested in all patients, since even young patients are not immune to major complications, and treatment may possibly delay long-term myelofibrotic transition. Acute haemorrhage should be treated by platelet transfusions, with or without platelet apheresis and with rapid control of the count by hydroxyurea. Vascular occlusive lesions should be treated with aspirin, with or without platelet apheresis and with hydroxyurea. Busulphan is suggested as the drug of choice for long-term therapy in patients over 40 years of age while hydroxyurea is proposed below this age. The place of interferon-alpha therapy has not yet been established but may have a particular role in women of child-bearing age.