Abstract
In accordance with the revised criteria of FAB classification in 1985 (Ann Intern Med 10) by FAB Co-operative Group, 32 cases diagnosed as erythroleukemia (EL) were re-classified. They were examined for the abnormal morphological findings of erythroblasts and FAB classification was re-evaluated for its validity.
Eleven cases belonged to M6 (Group A), while 21 cases did not belong to M6 (Group B). Control groups included 7 hematologically normal cases, 8 cases of megaloblastic anemia and 6 cases of hemolytic anemia.
Ultrastructural observation on erythroblasts from all cases was done and the presence of the abnormal findings was examined. Erythroblasts in control groups were also analysed because abnormal findings were found. A comparison of Group A and Group B was made by means of frequency of abnormal findings.
Statistically, atypism of the cytoplasm was marked in Group A, whereas atypism of the nucleus was marked in Group B. A correlation of abnormal findings between Group A and Group B suggented that atypism of the calls of Group A was more remarkable than Group B and discriminant function revealed the possibility of classification into two groups.
The FAB classification of optical examination corresponds with that of the ultrastructural findings, and this suggests an adequacy of revised classification.
