Triphenotypic acute leukemia

Leukemia Research 33 (2009) e83–e84 Contents lists available at ScienceDirect Leukemia Research journal homepage: www.elsevier.com/locate/leukres Letter to the Editor Triphenotypic acute leukemia with TRAP-positive blasts: A pathological rarity 1.... More

Leukemia Research 33 (2009) e83–e84 Contents lists available at ScienceDirect Leukemia Research journal homepage: www.elsevier.com/locate/leukres Letter to the Editor Triphenotypic acute leukemia with TRAP-positive blasts: A pathological rarity 1. Introduction The advent of extended panel immunophenotyping has led to increased identification of acute leukemias that express lineage infidelity or promiscuity. The 2001 WHO Classification [1] adopted a scoring system first proposed by the European Group for Immunological Characterization of Leukemias (EGIL) [2] that enabled precise classification of these neoplasms. Although the commonest of these “cross-lineage” leukemias are those that “aberrantly express” antigens of another lineage and about 4–8% acute leukemia are biphenotypic (BAL), a much smaller and ill-studied group are the acute tri-phenotypic or tri-lineal leukemias (TAL) [1–6]. We present a rare case of TAL diagnosed by its unusual cytochemical staining pattern, morphology and flow c Less