Acute monocytic leukemia

A subtype of acute myeloid leukemia

Acute monocytic leukemia (AML-M5) is a subtype of acute myeloid leukemia (AML), a cancer of the blood and bone marrow characterized by an overproduction of immature white blood cells known as monocytes. This condition is classified under the French-American-British (FAB) classification system as M5, which is further divided into M5a (poorly differentiated) and M5b (well differentiated).

Pathophysiology

Acute monocytic leukemia is characterized by the proliferation of monoblasts and promonocytes in the bone marrow and peripheral blood. These cells are part of the monocyte lineage, which normally develop into macrophages and dendritic cells that play a role in the immune system. In AML-M5, these cells fail to mature properly and accumulate, disrupting normal blood cell production.

Clinical Presentation

Patients with acute monocytic leukemia may present with symptoms related to anemia, thrombocytopenia, and neutropenia. Common symptoms include fatigue, pallor, easy bruising, bleeding, and increased susceptibility to infections. Additionally, due to the infiltration of leukemic cells, patients may experience gum hypertrophy, skin lesions, and central nervous system involvement.

Diagnosis

The diagnosis of acute monocytic leukemia is made through a combination of blood tests, bone marrow biopsy, and cytogenetic analysis. A complete blood count (CBC) often reveals leukocytosis with a high percentage of monoblasts. Bone marrow examination shows a predominance of monoblasts and promonocytes. Flow cytometry and immunophenotyping are used to confirm the monocytic lineage of the leukemic cells.

Treatment

The treatment of acute monocytic leukemia typically involves chemotherapy regimens similar to those used for other subtypes of AML. The standard induction therapy includes cytarabine and an anthracycline such as daunorubicin or idarubicin. Consolidation therapy may involve additional chemotherapy or hematopoietic stem cell transplantation for eligible patients.

Prognosis

The prognosis for patients with acute monocytic leukemia varies based on several factors, including age, overall health, and specific genetic abnormalities. Younger patients and those who achieve complete remission after initial treatment generally have a better prognosis. However, the overall survival rate remains lower compared to other AML subtypes.

Related pages

• Acute myeloid leukemia
• Leukemia
• Hematopoiesis
• Bone marrow

Gallery

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  Micrograph of acute monocytic leukemia

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  Acute monocytic leukemia