Introduction: Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) is a subtype of T-ALL and its clinical entity was established in recent years based on characteristic immunophenotyping and gene expression profiles. The cellular origin of ETP-ALL is supposed to be from common hematopoietic progenitors both for lymphoid and myeloid lineages because this leukemia phenotypically exhibits lymphoid, myeloid, and stem cell features. ETP-ALL comprises 5–15% of all T-ALL and is associated with a poor prognosis. The purpose of this chapter is to clarify the etiology, clinical picture, and therapeutic strategy of ETP-ALL showing two cases of this leukemia in our institution.
Part of the book: Leukemias