Which type of acute myeloid leukemia is characterized by minimal maturation of myeloid cells?

The classification of acute myeloid leukemia (AML) by the French-American-British (FAB) system identifies different subtypes based on the maturity of myeloid cells and other characteristics of the disease. In this system, FAB M1 is specifically characterized by the acute myeloid leukemia with minimal maturation of myeloid cells.

In FAB M1, the leukemic blast cells are predominantly myeloblasts, which do not show significant differentiation or maturation into more mature forms of myeloid cells. This lack of maturation is a defining feature of this subtype, indicating that the leukemic process has arrested at an early stage of myeloid differentiation.

This distinction is crucial for diagnosis and therapeutic strategies, as different subtypes of AML may respond differently to treatment. Therefore, a clear understanding of the maturation stage of the leukemic cells is essential for both accurate diagnosis and effective patient management.

The other subtypes, such as FAB M2, M3, and M4, exhibit varying degrees of maturation and other specific characteristics that differentiate them from FAB M1. For example, FAB M2 shows more maturation than M1, while M3 is associated with promyelocytic leukemia and characteristic clinical features.