Acute myelogenous leukemia (AML) is a cancer of the blood and bone marrow characterized by the rapid growth of abnormal myeloid cells. It is one of the most common types of leukemia in adults, accounting for approximately 80% of all cases.

AML can be further classified into different subtypes based on various genetic and clinical factors. In this article, we will explore 11 distinct subtypes of acute myelogenous leukemia.

1. Acute Promyelocytic Leukemia (APL)

APL is a subtype of AML characterized by a translocation between chromosomes 15 and 17, resulting in a fusion gene called PML-RARA.

This fusion protein disrupts the normal maturation of myeloid cells, leading to the accumulation of abnormal promyelocytes. APL has a distinctive morphology and is associated with a high risk of bleeding and disseminated intravascular coagulation.

2. Acute Myelomonocytic Leukemia (AMML)

AMML is a subtype of AML characterized by the presence of both myeloid blasts and monocytic cells. It is often associated with extramedullary involvement, such as skin infiltrates or gum hypertrophy.

AMML can present with a variety of clinical manifestations, including anemia, thrombocytopenia, and organ involvement.

3. Acute Megakaryoblastic Leukemia (AMKL)

AMKL is a subtype of AML characterized by the proliferation of abnormal megakaryoblasts. It is most commonly seen in children with Down syndrome, but can also occur in adults.

AMKL is associated with a poor prognosis and is often resistant to standard chemotherapy. It may require alternative treatment approaches, such as stem cell transplantation.

4. Acute Erythroid Leukemia (AEL)

AEL is a subtype of AML characterized by the predominance of erythroid blasts. It can be further classified into two subgroups: erythroid/myeloid (previously known as mixed lineage leukemia) and pure erythroid leukemia.

AEL is associated with a poor prognosis and is often refractory to treatment. It may require aggressive therapeutic interventions, such as intensive chemotherapy or stem cell transplantation.

5. Acute Basophilic Leukemia (ABL)

ABL is a rare subtype of AML characterized by the presence of abnormal basophils in the bone marrow. It is often associated with high white blood cell counts and can present with symptoms such as fatigue, bone pain, and enlarged spleen.

ABL is often resistant to standard chemotherapy and may require targeted therapies or experimental treatment approaches.

6. Acute Monocytic Leukemia (AMoL)

AMoL is a subtype of AML characterized by the presence of abnormal monocytic cells. It can present with a variety of clinical features, including skin infiltrates, gum hypertrophy, and organ involvement.

AMoL has a poor prognosis and is often associated with aggressive disease progression. It may require intensive chemotherapy and targeted treatments, such as monoclonal antibodies.

7. Acute Myeloblastic Leukemia with Maturation (M2)

M2 is a subtype of AML characterized by the presence of myeloblasts in various stages of maturation. It is one of the most common subtypes of AML and often presents with symptoms such as fatigue, fever, and easy bruising.

M2 is typically responsive to standard chemotherapy regimens and has a relatively good prognosis compared to other subtypes.

8. Acute Myeloid Leukemia with Minimal Differentiation (M0)

M0 is a subtype of AML characterized by the absence of specific markers of myeloid differentiation. It is a rare subtype and often associated with a poor prognosis.

M0 usually requires aggressive treatment approaches, such as intensive chemotherapy and stem cell transplantation.

9. Acute Myeloid Leukemia with FLT3-ITD Mutation

This subtype of AML is characterized by the presence of a specific mutation called FLT3-ITD (internal tandem duplication) in the FLT3 gene. FLT3-ITD is associated with a higher risk of relapse and a poor prognosis.

Targeted therapies, such as FLT3 inhibitors, are being evaluated for the treatment of AML with FLT3-ITD mutation.

t-AML is a subtype of AML that occurs as a result of previous exposure to chemotherapy or radiation therapy for other malignancies. It typically presents with a shorter latency period and is often associated with complex karyotypes.

The treatment of t-AML may involve different therapeutic strategies, such as alternative chemotherapy regimens or stem cell transplantation.

11. Acute Undifferentiated Leukemia (AUL)

AUL is a rare subtype of AML characterized by the absence of myeloid or lymphoid lineage-specific markers. It represents a diagnostic challenge and often requires extensive testing to exclude other types of leukemia or lymphoma.

AUL has a poor prognosis and usually necessitates intensive chemotherapy followed by stem cell transplantation.