Hematologic Features of Hepatosplenic T-Cell Lymphoma

Abstract

To the Editor We read with interest the article by Chen and colleagues1 in which they describe the clinical and pathologic characteristics of 7 cases of the rare CD4–/CD8– γδ subtype of T-cell large granular lymphocytic (T-LGL) leukemia. The authors state that 16 cases of CD4–/CD8– γδ T-cell neoplasm had initially been identified, but 9 had been excluded because they represented “various other types of γδ T-cell lymphoma/leukemia involving the blood and bone marrow.”1 It is unfortunate that the data on which these exclusions were made was not provided. This information would have been valuable, especially in determining whether any of the 9 excluded cases were, in fact, hepatosplenic T-cell lymphoma (HSTL), another rare disease with phenotypic similarities with CD4–/CD8– γδ T-LGL leukemia. The data from the resulting 7 cases described in the published series infer that the lack of isochromosome (7q), a feature of HSTL, was a major discriminator, as 6 of 6 tested cases were negative. However, the authors downplay the significance of cytogenetics by only stating that it “may be helpful in difficult cases” in distinguishing between CD4–/CD8– γδ T-LGL leukemia and HSTL. Instead they claim that, although the distinction between these 2 entities can be difficult, it may be readily achieved on morphologic studies and the pattern of splenic and marrow infiltration.1 We want to make particular comment on the …