transient abnormal myelopoiesis
Also written as: TAM — transient abnormal myelopoiesis
A pre-leukemic condition occurring in newborns with Down syndrome, characterized by abnormal blast cells that typically resolve spontaneously.
Full Definition
Transient abnormal myelopoiesis (TAM), also known as transient leukemia, is a unique pre-leukemic condition that occurs in approximately 10% of newborns with Down syndrome. The condition is characterized by the presence of blast cells in the blood and bone marrow that morphologically resemble acute megakaryoblastic leukemia. TAM typically presents within the first few weeks of life and spontaneously resolves within 3 months in most cases. However, approximately 20-30% of affected children will develop acute megakaryoblastic leukemia (AMKL) within the first 3-4 years of life. The condition is associated with mutations in the GATA1 gene and requires careful monitoring despite its transient nature.
Usage
Usage note: Commonly abbreviated as TAM; always associated with Down syndrome in the neonatal period.
In Context
- "The newborn with Down syndrome developed transient abnormal myelopoiesis with blast cells comprising 15% of the peripheral blood smear." — Pediatric hematology consultation