Intermittent melphalan in the treatment of essential thrombocytosis with haemorrhage or thrombosis.

178 episodes of essential thrombocytosis with symptoms of haemorrhage or thrombosis, were treated in 15 patients with melphalan (5 mg/m2 orally during 4 d). An average reduction in the platelet count of 77% was achieved by oral melphalan in 14 responding patients. 1 patient appeared to be refractory to oral therapy, but a decrease of the thrombocyte count was achieved after intravenous administration of melphalan. All responding patients experienced a relief of the thrombocytosis-associated clinical symptoms. Reduction of the thrombocyte count persisted for 3-4 wk.