Minimally differentiated acute myeloblastic leukemia
Encyclopedia
Minimally differentiated acute myeloblastic leukemia is a subtype of AML. It is classified as M0 by FAB. It represents 2–3% of all cases of AML. Although minimally differentiated AML was recognized earlier, criteria for FAB M0 were developed in 1991. The blasts in these cases cannot be recognized as myeloid based on morphology and cytochemistry
, but immunophenotyping
demonstrates myeloid antigens.
activity, and Auer rods
are not seen. The blasts react with antibodies to myeloperoxidase and antibodies to CD13, CD33
, and CD34
. Human leukocyte antigen
(HLA)-DR is positive in most patients. Occasional cases require in situ hybridization
to identify the myeloperoxidase gene315 or genomic profiling for early myeloid-associated genes. Abnormal and unfavorable karyotypes (e.g., loss of the long arm of chromosome 5 (5q-) and 7q-) and higher expression of the multidrug resistance glycoprotein (p170) are frequent. In general, minimally differentiated acute myeloblastic leukemia has a poor prognosis.
Cytochemistry
Cytochemistry is the biochemistry of cells, especially that of the macromolecules responsible for cell structure and function...
, but immunophenotyping
Immunophenotyping
Immunophenotyping is a technique used to study the protein expressed by cells. This technique is commonly used in basic science research and laboratory diagnostic purpose. This can be done on tissue section , cell suspension, etc. An example is the detection of tumor marker, such as in the...
demonstrates myeloid antigens.
Cytochemistry and Molecular Features
In acute myeloblastic leukemia (M0), the blasts are agranular and nonreactive when stained for myeloperoxidaseMyeloperoxidase
Myeloperoxidase is a peroxidase enzyme that in humans is encoded by the MPO gene. Myeloperoxidase is most abundantly expressed in neutrophil granulocytes . It is a lysosomal protein stored in azurophilic granules of the neutrophil...
activity, and Auer rods
Auer rods
Auer rods can be seen in the leukemic blasts of acute myeloid leukemia. Auer rods are clumps of azurophilic granular material that form elongated needles seen in the cytoplasm of leukemic blasts...
are not seen. The blasts react with antibodies to myeloperoxidase and antibodies to CD13, CD33
CD33
CD33 or Siglec-3 is a transmembrane receptor expressed on cells of myeloid lineage. It is usually considered myeloid-specific, but it can also be found on some lymphoid cells.It binds sialic acids, therefore is a member of the SIGLEC family of lectins....
, and CD34
CD34
CD34 molecule is a cluster of differentiation molecule present on certain cells within the human body. It is a cell surface glycoprotein and functions as a cell-cell adhesion factor. It may also mediate the attachment of stem cells to bone marrow extracellular matrix or directly to stromal cells...
. Human leukocyte antigen
Human leukocyte antigen
The human leukocyte antigen system is the name of the major histocompatibility complex in humans. The super locus contains a large number of genes related to immune system function in humans. This group of genes resides on chromosome 6, and encodes cell-surface antigen-presenting proteins and...
(HLA)-DR is positive in most patients. Occasional cases require in situ hybridization
In situ hybridization
In situ hybridization is a type of hybridization that uses a labeled complementary DNA or RNA strand to localize a specific DNA or RNA sequence in a portion or section of tissue , or, if the tissue is small enough , in the entire tissue...
to identify the myeloperoxidase gene315 or genomic profiling for early myeloid-associated genes. Abnormal and unfavorable karyotypes (e.g., loss of the long arm of chromosome 5 (5q-) and 7q-) and higher expression of the multidrug resistance glycoprotein (p170) are frequent. In general, minimally differentiated acute myeloblastic leukemia has a poor prognosis.
See also
- Acute myeloid leukemiaAcute myeloid leukemiaAcute myeloid leukemia , also known as acute myelogenous leukemia, is a cancer of the myeloid line of blood cells, characterized by the rapid growth of abnormal white blood cells that accumulate in the bone marrow and interfere with the production of normal blood cells. AML is the most common acute...
- Acute myeloblastic leukemia without maturationAcute myeloblastic leukemia without maturationAcute myeloblastic leukemia without maturation is a quickly progressing disease in which too many immature white blood cells are found in the blood and bone marrow.It is classified as "M1" in the FAB classification.- External links :...
(M1 in FABFrench-American-British classificationThe French-American-British classification systems refers to a series of classifications of hematologic diseases.It was first produced in 1976.Types include:* FAB classification of acute lymphoblastic leukemias...
) — - Acute myeloblastic leukemia with maturationAcute myeloblastic leukemia with maturationM2 is a subtype of AML .It is also known as "Acute Myeloblastic Leukemia with Maturation".-Cause:This subtype is characterized by a translocation of a part of chromosome 8 to chromosome 21, written as t...
(M2 in FABFrench-American-British classificationThe French-American-British classification systems refers to a series of classifications of hematologic diseases.It was first produced in 1976.Types include:* FAB classification of acute lymphoblastic leukemias...
) —