Minimally differentiated acute myeloid leukemia (AML-M0): comparison of 25 cases with other French-American-British subtypes.
We compared the immunophenotypic and karyotypic features of 25 cases of minimally differentiated acute myeloid leukemia (AML-M0) with those of 247 cases comprising all AML French-American-British (FAB) classification. Myeloperoxidase (MPO) was detectable with a specific monoclonal antibody in all cases of AML-M0, whereas CD13 and CD33 were both negative in 4 of the 25 cases. Thus, anti-MPO reliably detects minimal myeloid differentiation in AML-M0. CD34 and terminal deoxynucleotidyl transferase (TdT) were more frequently expressed in AML-M0 (96% and 68% of the cases, respectively) than in the other FAB subsets (P < .001 for both). By contrast, GP-170 and CD7 were less frequently expressed in AML-M0 than in FAB classes such as M1, M4, and M5 (P = .02 and .003, respectively). A total of 80% of AML-M0 cases carried lymphoid markers (including TdT), and 48% showed a coordinate positivity for two or more of them. CD2, CD5, CD10, and CD19 were expressed in a similar fashion among the different FAB groups, whereas CD4 expression was significantly more frequent in AML-M0, AML-M4, and AML-M5 (P = .014). AML-M0 was characterized by a more frequent occurrence of complex karyotypes. In addition, approximately 20% of cases had TdT positivity, complex karyotypes, and anomalies of chromosome 5 and/or 7, a pattern not observed in the other FAB subsets. Finally, 80% of anomalies of chromosome 5 and/or 7 in AML-M0 were comprised within complex karyotypes, whereas only 13% of the remaining FAB cases carried this feature. In summary, AML-M0 frequently expresses immunophenotypic and karyotypic aspects that are likely to identify a "stem cell" pattern.
Venditti
A
A
Cattedra di Ematologia-Ospedale S. Eugenio and Cattedra di Immunoematologia, Università di Roma Tor Vergata, Italy.
Del Poeta
G
G
Buccisano
F
F
Tamburini
A
A
Cox
M C
MC
Stasi
R
R
Bruno
A
A
Aronica
G
G
Maffei
L
L
Suppo
G
G
Simone
M D
MD
Forte
L
L
Cordero
V
V
Postorino
M
M
Tufilli
V
V
Isacchi
G
G
Masi
M
M
Papa
G
G
Amadori
S
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002454:Cell Differentiation; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D007621:Karyotyping; D015470:Leukemia, Myeloid, Acute / Q000145:classification* / Q000235:genetics / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged