Acute biphenotypic leukaemia

Acute biphenotypic leukaemia (ABL) is a rare subtype of leukaemia, a group of cancers that generally begin in the bone marrow and result in high numbers of abnormal white blood cells. ABL is characterized by the presence of both myeloid and lymphoid features in the same patient, hence the term "biphenotypic".

Definition

The World Health Organization (WHO) defines ABL as a leukaemia that does not fit into any of the other defined types of leukaemia. It is characterized by the presence of both myeloid and lymphoid features in the same patient. This is determined by the use of immunophenotyping, a technique used to study the protein expressed by cells.

Epidemiology

ABL is a rare disease, accounting for less than 5% of all acute leukaemias. It can occur at any age, but is more common in adults than in children.

Pathophysiology

In ABL, the malignant cells express markers of both myeloid and lymphoid lineages. This is thought to occur due to a mutation in a multipotent stem cell, which gives rise to both myeloid and lymphoid cells.

Clinical Features

Patients with ABL typically present with symptoms common to other types of leukaemia, such as fatigue, fever, and bleeding. The diagnosis is confirmed by bone marrow examination and immunophenotyping.

Treatment

The treatment of ABL is challenging due to its mixed phenotype. It typically involves intensive chemotherapy regimens, similar to those used for other types of acute leukaemias. In some cases, a stem cell transplant may be considered.

Prognosis

The prognosis of ABL is generally poor, with a lower survival rate compared to other types of acute leukaemias. However, outcomes can vary widely depending on factors such as age, overall health, and response to treatment.

See Also

• Leukaemia
• Acute lymphoblastic leukaemia
• Acute myeloid leukaemia
• Stem cell transplant