Leukemia in which the involved cell shows little or no differentiation, usually consisting of blast cells; two types are distinguished, acute lymphocytic and acute myelogenous leukemia.

Acute leukemia or acute leukaemia is a family of serious medical conditions relating to an original diagnosis of leukemia. In most cases, these can be classified according to the lineage, myeloid or lymphoid, of the malignant cells that grow uncontrolled, but some are mixed and for those such an assignment is not possible. Forms of acute leukemia include: Acute myeloid leukemia (AML), a rare form of which is acute erythroid leukemia. Acute lymphoblastic leukemia (ALL) including T-cell acute lymphoblastic leukemia...