It is a rare form of acute leukemia.
It accounts for 0.5-1% of acute leukemia cases, including pediatric and adult cases.
Probably derived from neoplastic transformation of an early stem cell precursor with the ability to undergo myeloid and lymphoid differentiation.
It comprises two main subgroups whether myeloid and B. cell lymphoid or myeloid and T-cell lymphoid.
MPAL has two distinct cytogenetic subgroups: with BCR-ABL rearrangement, and with MLL rearrangement, making up 20 to 25% of cases, while the majority of patients have chromosomal abnormalities.