Myelofibrosis with myeloid metaplasia following essential thrombocythaemia

We report a male patient in whom a diagnosis of essential thrombocythaemia was made at the age of 25. The clinical course was characterised by recurrent thrombotic episodes during the first few years of the disease, followed by a relatively benign course. He was treated with 32P, nitrogen mustard and plateletpheresis. A transformation into myelofibrosis with myeloid metaplasia was revealed 20 years after ET diagnosis. The length of the disease and the 32P therapy are discussed as factors favouring this metamorphosis.