acute myeloid leukemia

Infant with
stridor. Lateral radiograph of the airway (above) shows a large amount of retropharyngeal soft tissue swelling. Axial CT with contrast of the neck (below) shows a large round low density lesion in the left parapharyngeal space.The diagnosis was chloroma in a patient with acute myelogenous leukemia.
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Acute myeloid leukemia (AML), also referred to as acute myelogenous leukemia, is a hematological malignancy characterized by the abnormal clonal proliferation of immature myeloid precursors (myeloblasts) or poorly differentiated cells of the hematopoietic system. It primary infiltrates the bone marrow, but the disease can also extend to blood and other tissues.

Epidemiology

It is more common in middle-aged and elderly patients, with a median age of diagnosis at 70 years. The M: F rate varies from 1.1 in the 5 decade to about 1.8 in the 8 decade of life .

AML only accounts for ~20% of all childhood leukaemias, c.f. to acute lymphoblastic leukemia (ALL), which represents ~80% of leukaemias at this age group .

It has been reported a solid ethnic component in the distribution of most types of AML, with a strong predominance among the white ethnicity group . 

Risk factors   

Clinical presentation 

AML tends to present with vague and nonspecific symptoms such as fatigue and is most commonly revealed on full blood count tests, where anemia, thrombocytopenia, and/or neutropenia are demonstrated .

Described symptoms associated with bone marrow failure include :

  • fevers
  • bleeding gums
  • multiple ecchymoses
  • dyspnea on exertion
  • anginal chest pain
  • refractory upper respiratory infection symptoms

Extramedullary leukemic infiltration can lead to organ-involved symptoms such as hepatosplenomegaly, leukemia cutis, lymphadenopathy, gingival hyperplasia, and neurological symptoms .

Pathology

Location

The leukemic myeloblasts can commonly be identified either in peripheral blood smears or bone marrow aspirate. Eventually, there is infiltration of other organs and tissues:

Classification

The revised 2016 World Health Organization (WHO) classification of tumors of hematopoietic and lymphoid tissues classifies AML in multiple subtypes .

Depending on the type of cell lineage involved, AML can be divided into specific morphologic subgroups.

Microscopic appearance

The leukemic cells are characterized by very little cytoplasm, which holds fine azurophilic granules and Auer bodies or rods. Irregular nuclei and distinct nucleoli are also features of those cells .

Treatment and prognosis

AML has an overall poor prognosis compared to the other main types of leukemia, having ~30% 5-year survival rate . This is most evident among elderly patients over 65 years, where up to 70% die within 1 year of diagnosis .

Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu Akute myeloische Leukämie:
Myelodysplastisches
Syndrom
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Myelosarkom
 
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