Changes

==Definition / Description of Disease==

==Definition / Description of Disease==

This is a distinct entity in the World Health Organization (WHO) classification system within the section of [[Acute Myeloid Leukemia (AML), Not Otherwise Specified]]<ref name=":0">Arber DA, et al., (2017). Acute myeloid leukaemia with recurrent genetic abnormalities, in World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues, Revised 4th edition. Swerdlow SH, Campo E, Harris NL, Jaffe ES, Pileri SA, Stein H, Thiele J, Arber DA, Hasserjian RP, Le Beau MM, Orazi A, and Siebert R, Editors. IARC Press: Lyon, France, p158-159.</ref>.  This entity does ''not'' meet the criteria for inclusion in any of the other AML groups (i.e. AML with Recurrent Genetic Abnormalities, AML with Myelodysplasia-Related Changes, or Therapy-Related Myeloid Neoplasms).  There is currently no known recurrent chromosomal abnormality associated with this entity<ref name=":0" />.

This is a distinct entity in the World Health Organization (WHO) classification system within the section of [[HAEM4:Acute Myeloid Leukemia (AML), Not Otherwise Specified]]<ref name=":0">Arber DA, et al., (2017). Acute myeloid leukaemia with recurrent genetic abnormalities, in World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues, Revised 4th edition. Swerdlow SH, Campo E, Harris NL, Jaffe ES, Pileri SA, Stein H, Thiele J, Arber DA, Hasserjian RP, Le Beau MM, Orazi A, and Siebert R, Editors. IARC Press: Lyon, France, p158-159.</ref>.  This entity does ''not'' meet the criteria for inclusion in any of the other AML groups (i.e. AML with Recurrent Genetic Abnormalities, AML with Myelodysplasia-Related Changes, or Therapy-Related Myeloid Neoplasms).  There is currently no known recurrent chromosomal abnormality associated with this entity<ref name=":0" />.

==Synonyms / Terminology==

==Synonyms / Terminology==

==Morphologic Features==

==Morphologic Features==

This AML subtype is characterized by the presence of ≥20% blasts in the bone marrow or blood combined with evidence of maturation in the bone marrow; specifically, ≥10% maturing cells of granulocytic lineage and <20% cells of monocyte lineage<ref name=":0" />.  The blasts may or may not have azurophilic granulation but Auer rods and hypercullularity are typically observed.  Bone marrow cell constitution includes ≥10% promyelocytes, myelocytes and mature nuetrophils, as well as elevated eosinophil precursors which lack the cytological or cytochemical abnormalities characteristic of the abnormal eosinophils in [[Acute Myeloid Leukemia (AML) with inv(16)(p13.1q22) or t(16;16)(p13.1;q22); CBFB-MYH11]].  Basophils and mast calls are sometimes increased, and variable dysplasia occurs but ≤50% of cells in two lineages show dysplasia.

This AML subtype is characterized by the presence of ≥20% blasts in the bone marrow or blood combined with evidence of maturation in the bone marrow; specifically, ≥10% maturing cells of granulocytic lineage and <20% cells of monocyte lineage<ref name=":0" />.  The blasts may or may not have azurophilic granulation but Auer rods and hypercullularity are typically observed.  Bone marrow cell constitution includes ≥10% promyelocytes, myelocytes and mature nuetrophils, as well as elevated eosinophil precursors which lack the cytological or cytochemical abnormalities characteristic of the abnormal eosinophils in [[HAEM5:Acute myeloid leukaemia with CBFB::MYH11 fusion]].  Basophils and mast calls are sometimes increased, and variable dysplasia occurs but ≤50% of cells in two lineages show dysplasia.

==Immunophenotype==

==Immunophenotype==

==Clinical Significance (Diagnosis, Prognosis and Therapeutic Implications)==

==Clinical Significance (Diagnosis, Prognosis and Therapeutic Implications)==

The differential diagnosis includes 1) MDS with excess blasts in cases with a low blast percentage, 2) AML without Maturation in cases with a high blast percentage, and 3) [[Acute Myelomonocytic Leukemia]] in cases with increased monocytes.  Of note, [[Acute Myeloid Leukemia (AML) with t(8;21)(q22;q22.1);RUNX1-RUNX1T1]] typically has overlapping histologic features as AML with Maturation, but the former should be classified according to its genetic abnormality (i.e. as a subcategory of the entity [[Acute Myeloid Leukemia (AML) with Recurrent Genetic Abnormalities]]).

The differential diagnosis includes 1) MDS with excess blasts in cases with a low blast percentage, 2) AML without Maturation in cases with a high blast percentage, and 3) [[HAEM5:Acute myelomonocytic leukaemia]] in cases with increased monocytes.  Of note, [[Acute Myeloid Leukemia (AML) with t(8;21)(q22;q22.1);RUNX1-RUNX1T1]] typically has overlapping histologic features as AML with Maturation, but the former should be classified according to its genetic abnormality (i.e. as a subcategory of the entity [[HAEM4:Acute Myeloid Leukemia (AML) with Recurrent Genetic Abnormalities]]).

==Familial Forms==

==Familial Forms==