Acquired refractory anaemia with excess of blasts of promegakaryoblastic type.

A case of acquired refractory anaemia with excess of blasts (RAEB) of the promegakaryoblastic type is described. The promegakaryoblastic origin was demonstrated by means of ultrastructural cytochemistry (platelet peroxidase) and immunological methods. The blasts were also 5'-Nucleotidase positive. After a stable course over 2.5 years the patient died from hematological failure, his marrow demonstrating a high degree of fibrosis.