Acute of fulminating myelofibrosis.

: Patients who run a fulminating course in association with histologically proven myelofibrosis are distinctly unusual, since the natural history of this entity is characteristically one of slow progression. Because of its rarity and proteam manifestations, acute myelofibrosis may easily go unrecognized. We report 2 such patients. In one, rapid clinical deterioration was dominated by spreading skin lesions, and in the other by refractory intravascular haemolysis. There was no splenomegaly in the first patient, and it was minimal in the second. Although it is seen in frequently, it should be emphasized that myelofibrosis may arise de novo as an acute illness in which the usual degree of splenomegaly is absent.