title: Primary cutaneous T-cell lymphoma expressing FOXP3: a case report supporting the existence of malignancies of regulatory T cells.
abstract: Regulatory T (Treg) cells, which represent 5% to 10% of peripheral T cells, regulate the activities of T-cell subsets by performing immunosuppressive functions and thus preventing the development of autoimmune responses. The majority of Treg cells are CD4+, CD25+, and FOXP3+. Recently, it has been demonstrated that the tumor cells in adult T-cell leukemia lymphomas can function as Treg, raising the question of whether any variant of primary cutaneous T-cell lymphoma may also express a regulatory phenotype. We describe an extraordinary case of primary cutaneous T-cell lymphoma clinically characterized by protean cutaneous manifestations and histologically showing a pattern consistent with epidermotropic pleomorphic medium-/large-cell primary cutaneous T-cell lymphoma. The majority of neoplastic cells were CD4+ CD25+ T cells and strongly expressed FOXP3. With this background, the current case, characterized by an aggressive course requiring polychemotherapy, may support the existence of lymphoproliferative malignancies of Treg cells.
authors.affiliation: Institute of Dermatological Sciences, Istituto di Ricovero e Cura a Carattere Scientifico Fondazione Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, University of Milan, Milan, Italy.
authors.forename: Angelo V
authors.initials: AV
authors.lastname: Marzano
authors.forename: Pamela
authors.initials: P
authors.lastname: Vezzoli
authors.forename: Daniele
authors.initials: D
authors.lastname: Fanoni
authors.forename: Luigia
authors.initials: L
authors.lastname: Venegoni
authors.forename: Emilio
authors.initials: E
authors.lastname: Berti
mesh_terms: D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D015415:Biomarkers / Q000378:metabolism; D001707:Biopsy, Needle; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D005500:Follow-Up Studies; D051858:Forkhead Transcription Factors / Q000276:immunology* / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008213:Lymphocyte Activation; D016410:Lymphoma, T-Cell, Cutaneous / Q000188:drug therapy / Q000276:immunology / Q000473:pathology*; D008297:Male; D018570:Risk Assessment; D012878:Skin Neoplasms / Q000188:drug therapy / Q000276:immunology / Q000473:pathology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D051858:Forkhead Transcription Factors