Multiple vacuoles formation in erythroblasts in an erythroleukaemic patient.

Peculiar erythroblasts with multiple vacuoles were observed in the bone marrow of an erythroleukaemic patient. Some erythroblasts contained more than 80 vacuoles on a thin section. The contents of vacuoles were amorphous with low electron density. No transitional form from mitochondria or other organelles was observed. Since these vacuolated erythroblasts were clearly distinguishable from megaloblastoid erythraemia cells, multiple vacuoles formation is presumably attributable to the disturbance of microconnection net work in the normal red cell series.