Clonal expansion of myeloid blasts in bone marrow, peripheral blood or other organs.
FAB classification:
WHO classification:
Bone marrow is markedly hypercellular, sometimes hypocellular (especially therapy-related AML), myelopoiesis is usually markedly increased with a differentiation arrest and increased myeloblast (monoblast) levels above 20%. Megakaryocytes and erythropiesis are residual (except M6 and M7), M7 leukemia causes significant fibrosis.
Most common sites of infiltration are the spleen, liver, lymph nodes and other, however significant organomegaly is uncommon. Sometimes tumoriform lesions (myelosarcoma) may be found.
Secondary symptoms: bleeding, infections, anemia.
Acute myeloid leukemia, hypoplastic, bone marrow: Hypoplastic acute myeloic leukemia, HE 100x (73112) Hypoplastic acute myeloic leukemia, PAS 100x (73113)
Acute meyloid leukemia, kidney, infiltration into the glomerulus: Kidney in acute myeloic leukemia, HE 100x (72796)