Bone marrow neoplastic

Bone marrow - neoplastic myeloid

AML not otherwise specified

AML with maturation (FAB AML M2)



Last author update: 1 February 2013
Last staff update: 22 September 2023

Copyright: 2001-2024, PathologyOutlines.com, Inc.

PubMed Search: Acute myeloid leukemia with maturation (FAB AML M2)

Page views in 2023: 15,418
Page views in 2024 to date: 3,817
Cite this page: Mihova D. AML with maturation (FAB AML M2). PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/leukemiaM2.html. Accessed March 19th, 2024.
Definition / general
  • 10% of AML cases; 5% of childhood leukemias
  • Any age, 20% are < 25 years and 40% are 60 years+
  • Anemia, thrombocytopenia, neutropenia; variable number of blasts in peripheral blood
  • Variable prognosis
  • Criteria for diagnosis: 20%+ nonerythroid cells in peripheral blood or bone marrow are myeloblasts; monocytic precursors are < 20% in bone marrow and granulocytes are 10%+ of cells
  • Enzyme cytochemistry: most blasts are positive for myeloperoxidase or Sudan Black B, and chloroacetate esterase
Case reports
Microscopic (histologic) description
  • Usually hypercellular marrow
  • Full range of myeloid maturation through maturing neutrophils, often with abnormal segmentation and 10%+ bone marrow cells with variable degree of dysplasia
  • Auer rods in 70% of blasts; myeloblasts with or without azurophilic granules
  • Erythroid and megakaryocyte precursors may have dysplastic changes
  • Often increased eosinophilic precursors without cytological and cytochemical abnormalities of inv(16)(p13.1q22)
  • Basophils may be increased, rarely mast cell hyperplasia (Indian J Pathol Microbiol 2007;50:655)
Microscopic (histologic) images

AFIP images
Missing Image

Bone marrow
biopsy: markedly
hypercellular
marrow

Missing Image Missing Image Missing Image

Diagnosed as AML with maturation because no t(15;17) and no DIC but FISH not done, so may actually be acute promyelocytic leukemia

Missing Image

Myeloperoxidase positive blasts

Missing Image

Erythroid cells are negative



Bone marrow smears (Wright-Giemsa):
Missing Image

Type III myeloblasts

Missing Image

Myeloblasts,
promyelocytes,
myelocytes and
neutrophils

Missing Image

Several myeloblasts and maturing forms

Missing Image

Pseudopods, cytoplasm and prominent Auer rods

Missing Image

Several blasts have prominent nucleoli and Auer rods

Positive stains
Negative stains
Electron microscopy images

AFIP images
Missing Image

Numerous primary granules and fusion of Auer rods

Molecular / cytogenetics description
Back to top
Image 01 Image 02