Emperipolesis and annulate lamellae in erythroleukaemia.

The bone marrow in the erythraemic phase of 2 erythroleukaemic patients was studied electron microscopically. Emperipolesis of erythrocytes as well as annulate lamellae were revealed in the cytoplasm of the erythroblasts of these cases. It is assumed that these findings show a high rate of erythroblastic proliferation. This is the first report of emperipolesis within the erythroblast by erythroleukaemia. In addition, other various abnormalities, namely, nuclear-cytoplasmic asynchrony, nuclear bleb or cleft formation, abundant glycogen particles and ferruginous micelles in mitochondria such as described in some previous reports, were also recognized.