title: Purpuric adult T-cell leukaemia/lymphoma: expansion of unusual CD4/CD8 double-negative malignant T cells expressing CCR4 but bearing the cytotoxic molecule granzyme B.
abstract: A 78-year-old Japanese woman with adult T-cell leukaemia/lymphoma (ATL) presented with an unusual purpuric and erythematous eruption on the face and trunk. Immunohistochemical and flow cytometric analyses showed that the tumour cells were CD4/CD8 double-negative, and expressed CCR4 T-helper (Th) 2 chemokine receptors. Despite these features, the cells aberrantly produced granzyme B, which is a cytotoxic molecule usually produced by CD8(+) cytotoxic T cells, natural killer cells, or occasionally by Th1 cells. In a purpuric lesion, extravasation of erythrocytes was associated with an infiltrate of these cytotoxic tumour cells. Our case suggests phenotypical and functional heterogeneity of tumour cells in ATL, which may be closely related to the clinical appearance of the skin eruption.
authors.affiliation: Department of Dermatology, School of Medicine, University of Occupational and Environmental Health, Japan, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyusyu 807-8555, Japan. t-shima@med.uoeh-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Shimauchi
authors.forename: Y
authors.initials: Y
authors.lastname: Hirokawa
authors.forename: Y
authors.initials: Y
authors.lastname: Tokura
mesh_terms: D000368:Aged; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D005260:Female; D053804:Granzymes; D006801:Humans; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000276:immunology* / Q000473:pathology; D017254:Leukemic Infiltration / Q000276:immunology; D011693:Purpura / Q000276:immunology* / Q000473:pathology; D054398:Receptors, CCR4; D019707:Receptors, Chemokine / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000378:metabolism*; D012867:Skin / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: C515354:CCR4 protein, human; D015704:CD4 Antigens; D016827:CD8 Antigens; D054398:Receptors, CCR4; D019707:Receptors, Chemokine; C509213:GZMB protein, human; D053804:Granzymes; D012697:Serine Endopeptidases