Immunophenotypic Characterization of T-Cell Prolymphocytic Leukemia

Abstract

OBJECTIVES: To review clinical data, cytogenetic findings, and flow cytometric analysis in 20 patients with T-cell prolymphocytic leukemia (T-PLL), a rare, aggressive, mature T-cell leukemia with poor prognosis and short survival. METHODS: Using multiparameter flow cytometry with a large combination of antibodies, we summarize the immunophenotypic features of T-PLL, including unusual immunophenotypic variants, and illustrate immunophenotypic clues that may help distinguish this entity from other T-cell malignancies. RESULTS: By flow cytometry, T-PLL is characterized by a postthymic mature T-cell immunophenotype with a variety of abnormalities that usually allow distinction from other mature T-cell leukemias. CONCLUSIONS: Although definitive diagnosis of T-PLL requires a systemic approach with integration of clinical data, morphology, immunophenotype, cytogenetics/fluorescence in situ hybridization, and molecular features, our results indicate immunophenotyping by multiparameter flow cytometry greatly facilitates diagnosis and assists with subclassification of this mature T-cell leukemia.