Acute eosinophilic leukemia (AEL) is a rare subtype of acute myeloid leukemia

Acute myeloid leukemia

Acute 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...

 with 50 to 80 percent of eosinophilic

Eosinophilic

Eosinophilic refers to the staining of certain tissues, cells, or organelles after they have been washed with eosin, a dye.Eosin is an acidic dye; thus, the structure being stained is basic....

 cells in the blood and marrow. It can arise de novo

Mutation

In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...

 or may develop in patients having the chronic form of a hypereosinophilic syndrome

Hypereosinophilic syndrome

The hypereosinophilic syndrome is a disease characterized by a persistently elevated eosinophil count in the blood for at least six months without any recognizable cause, with involvement of either the heart, nervous system, or bone marrow.HES is a diagnosis of exclusion, after clonal...

. Patients with acute eosinophilic leukemia have a propensity for developing bronchospasm

Bronchospasm

Bronchospasm or a bronchial spasm is a sudden constriction of the muscles in the walls of the bronchioles. It is caused by the release of substances from mast cells or basophils under the influence of anaphylatoxins...

 and heart failure from endomyocardial fibrosis. Hepatomegaly

Hepatomegaly

Hepatomegaly is the condition of having an enlarged liver. It is a nonspecific medical sign having many causes, which can broadly be broken down into infection, direct toxicity, hepatic tumours, or metabolic disorder. Often, hepatomegaly will present as an abdominal mass...

 and splenomegaly

Splenomegaly

Splenomegaly is an enlargement of the spleen. The spleen usually lies in the left upper quadrant of the human abdomen. It is one of the four cardinal signs of hypersplenism, some reduction in the number of circulating blood cells affecting granulocytes, erythrocytes or platelets in any...

are more common than in other variants of AML.

Diagnosis

A specific histochemical reaction, cyanide-resistant peroxidase, permits identification of leukemic blast cells with eosinophilic differentiation and diagnosis of acute eosinoblastic leukemia in some cases of AML with few identifiable eosinophils in blood or marrow.

Treatment and Prognosis

Acute eosinophilic leukemia is treated as other subtypes of AML. Response to treatment is approximately the same as in other types of AML.