Refractory anemia with excess blasts in transformation

Refractory Anemia with Excess Blasts in Transformation (RAEB-T) was a classification previously used in the French-American-British (FAB) classification system to describe a specific form of myelodysplastic syndrome (MDS) that exhibits excessive blasts in the bone marrow or blood, nearing the blast count of acute myeloid leukemia (AML). However, this classification has been largely replaced by the World Health Organization (WHO) classification system, which integrates RAEB-T into the broader category of AML.

Definition

RAEB-T was defined under the FAB classification as a subtype of MDS characterized by the presence of 20-30% myeloblasts in the bone marrow or 5-19% blasts in the peripheral blood. This condition represented a transitional phase between MDS and AML, indicating a higher risk of transformation into full-blown leukemia.

Clinical Features

Patients with RAEB-T typically presented with symptoms associated with bone marrow failure, including anemia, thrombocytopenia (low platelet count), and neutropenia (low neutrophil count). Common clinical manifestations included fatigue, pallor, easy bruising, and increased susceptibility to infections.

Diagnosis

Diagnosis of RAEB-T involved a combination of hematological tests, including complete blood count (CBC), bone marrow biopsy, and cytogenetic analysis. The presence of specific chromosomal abnormalities could aid in diagnosis and prognosis.

Treatment

Treatment options for RAEB-T were limited and primarily focused on supportive care, including blood transfusions, growth factor therapy, and management of infections. In some cases, chemotherapy or hematopoietic stem cell transplantation might have been considered, especially for younger patients or those in relatively good health.

Prognosis

The prognosis for patients diagnosed with RAEB-T was generally poor, with a high risk of progression to AML. The median survival was typically short, ranging from several months to a few years, depending on various factors including patient age, general health, and specific genetic mutations.

Historical Context and Current Classification

The FAB classification, including RAEB-T, was used extensively until the early 2000s when it was superseded by the WHO classification. The WHO system no longer recognizes RAEB-T as a distinct entity but categorizes these patients under AML with myelodysplasia-related changes. This change reflects a better understanding of the genetic and molecular underpinnings of these diseases and aims to improve the stratification of patients for treatment.

See Also

• Myelodysplastic syndrome
• Acute myeloid leukemia
• Bone marrow biopsy
• Chromosomal abnormalities in cancer