World Library  
Flag as Inappropriate
Email this Article

Acute megakaryoblastic leukemia

Article Id: WHEBN0016187658
Reproduction Date:

Title: Acute megakaryoblastic leukemia  
Author: World Heritage Encyclopedia
Language: English
Subject: Acute myeloid leukemia, Acute myeloblastic leukemia with maturation, Leukemia, Chromosomal abnormalities, 46, XX/XY
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Acute megakaryoblastic leukemia

Acute megakaryoblastic leukemia
AML-M7, bone marrow section
Classification and external resources
Specialty Hematology and oncology
ICD-10 C94.2
ICD-O M9910/3
MeSH D007947

Acute megakaryoblastic leukemia (AMKL) is a form of leukemia where a majority of the blasts are megakaryoblastic.[1]

It is classified under M7 in the French-American-British classification.[2]

This category of AML is associate with 30% or more blasts in the marrow, blast are identified as being of megakaryocyte lineage by expression of megakaryocyte specific antigens and platelet peroxidase reaction on electron microscopy.

Causes

It is associated with GATA1, and risks are increased in individuals with Down syndrome.[3]

However, not all cases are associated with Down syndrome,[4] and other genes can also be associated with AMKL.[5]

Another related gene is MKL1, which is also known as "MAL".[6] This gene is a cofactor of serum response factor.[7]

Signs and symptoms

In adults, include pancytopenia with low blast counts in the blood, myelofibrosis, an absence of lymphadenopathy and hepatosplenomegaly, poor response to chemotherapy, and short clinical course. In children, the same clinical presentation but with variable course especially in very young children; both leukocytosis and organomegaly may be present in children with M7.

In the first three years of life, megakaryoblastic leukemia is the most common type of leukemia in patients with Down syndrome.[8]

Diagnosis

The morphology of cells was observed by means of bone marrow smear; the immunophenotype was detected by flow cytometry and immunohistochemistry assay.[9]

In blood and bone marrow smears megakaryoblasts are usually medium-sized to large cells with a high nuclear-cytoplasmic ratio. Nuclear chromatin is dense and homogeneous. There is scanty, variable basophilic cytoplasm which may be vacuolated. An irregular cytoplasmic border is often noted in some of the megakaryoblasts and occasionally projections resembling budding atypical platelets are present. Megakaryoblasts lack myeloperoxidase (MPO) activity and stain negatively with Sudan black B. They are alpha naphthyl butyrate esterase negative and manifest variable alpha naphythyl acetate esterase activity usually in scattered clumps or granules in the cytoplasm. PAS staining also varies from negative to focal or granular positivity, to strongly positive staining. A marrow aspirate is difficult to obtain in many cases because of variable degree of myelofibrosis. More precise identification by immunophenotyping or with electron microscopy (EM). Immunophenotyping using MoAb to megakaryocyte restricted antigen (CD41 and CD61) may be diagnostic.[10]

Prognosis

Complete remission and long-term survival are more common in children than adults.

Prognosis depends upon the cause. One third of cases is associated with a t(1;22)(p13;q13) mutation in children. These cases carry a poor prognosis.[11]

Another third of cases is found in Down syndrome. These cases have a reasonably fair prognosis.

The last third of cases may be heterogeneous, and carry a poor prognosis.[12]

See also

References

  1. ^
  2. ^
  3. ^
  4. ^
  5. ^
  6. ^
  7. ^
  8. ^
  9. ^
  10. ^
  11. ^ Huret JL . t(1;22)(p13;q13). Atlas Genet Cytogenet Oncol Haematol.
  12. ^ Cuneo A, Cavazzini F, Castoldi GL . Acute megakaryoblastic leukemia (AMegL), M7 acute non lymphocytic leukemia (M7-ANLL). Atlas Genet Cytogenet Oncol Haematol.

External links

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.