title: Invasive thymoma with CD4+CD8+ double-positive T cell lymphocytosis.
abstract: Lymphocytosis in the peripheral blood is a very rare manifestation of thymoma. A 45-year-old man presented with a giant mediastinal mass involving pleural dissemination and peripheral T cell lymphocytosis. Biopsy of the mediastinal mass revealed invasive thymoma, and two-color analysis of peripheral lymphocytes showed a marked increase in CD4+CD8+ double-positive cells. Both thymoma and lymphocytosis were improved by a combination of chemotherapy and mediastinal irradiation.
authors.affiliation: First Department of Medicine, Tokyo Women's Medical College, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Tamaoki
authors.forename: A
authors.initials: A
authors.lastname: Chiyotani
authors.forename: A
authors.initials: A
authors.lastname: Nagai
authors.forename: K
authors.initials: K
authors.lastname: Konno
mesh_terms: D015704:CD4 Antigens / Q000032:analysis*; D016516:CD4-CD8 Ratio; D016827:CD8 Antigens / Q000032:analysis*; D006801:Humans; D008218:Lymphocytosis / Q000150:complications*; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000276:immunology*; D013945:Thymoma / Q000097:blood / Q000276:immunology* / Q000473:pathology; D013953:Thymus Neoplasms / Q000097:blood / Q000276:immunology* / Q000473:pathology
chemical_list: D015704:CD4 Antigens; D016827:CD8 Antigens