title: Hypereosinophilia in a patient with invasive thymoma with clonal T-lymphocyte expansion expressing CD4, CD8, and CD25 antigens.
abstract: We report the case of a patient with hypereosinophilia and invasive thymoma harboring probable clonal proliferation of CD4+, CD8+, and CD25+ T-lymphocytes. A 64-year-old woman had eosinophilia (14.1 x 10(9)/L) and an anterior mediastinal tumor with elevated levels of serum immunoglobulin E (609.8 mg/dL) and interleukin 5 (239 pg/mL). Bone marrow aspirate showed marked infiltration by morphologically normal eosinophils with a normal karyotype but no FIP1L1-PDGFRA fusion gene. Flow cytometric analysis revealed an increasing number of CD3+/CD25+ lymphocytes in the peripheral blood, and the resected thymoma had infiltrated lymphocytes with CD4/CD8/CD25 antigens. Moreover, the thymoma had T-cell receptor rearrangements with a cytogenetically clonal nature, ie, t(2;4)(p22;q26). Although the number of patients with thymoma showing hypereosinophilia is small, this case suggests that a subset of patients with thymoma may have clonal expansion of T-lymphocytes with abnormal phenotypes that affect clinical manifestations, including hypereosinophilia.
authors.affiliation: First Department of Internal Medicine, Tokyo Medical University, Tokyo, Japan. m-sumi@mta.biglobe.ne.jp
authors.forename: Masahiko
authors.initials: M
authors.lastname: Sumi
authors.forename: Kosuke
authors.initials: K
authors.lastname: Nunoda
authors.forename: Tomonori
authors.initials: T
authors.lastname: Mizutani
authors.forename: Yuko
authors.initials: Y
authors.lastname: Ishii
authors.forename: Akihiko
authors.initials: A
authors.lastname: Gotoh
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Kimura
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Suga
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Ohira
authors.forename: Kuniharu
authors.initials: K
authors.lastname: Miyajima
authors.forename: Hiromi
authors.initials: H
authors.lastname: Serizawa
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Mukai
authors.forename: Harubumi
authors.initials: H
authors.lastname: Kato
authors.forename: Kazuma
authors.initials: K
authors.lastname: Ohyashiki
mesh_terms: D015703:Antigens, CD / Q000096:biosynthesis*; D049109:Cell Proliferation; D004802:Eosinophilia / Q000097:blood* / Q000150:complications / Q000235:genetics / Q000473:pathology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008875:Middle Aged; D015514:Oncogene Proteins, Fusion; D020796:Receptor, Platelet-Derived Growth Factor alpha; D013601:T-Lymphocytes / Q000378:metabolism* / Q000473:pathology; D013945:Thymoma / Q000097:blood* / Q000150:complications / Q000235:genetics / Q000473:pathology; D013953:Thymus Neoplasms / Q000097:blood* / Q000150:complications / Q000235:genetics / Q000473:pathology; D039221:mRNA Cleavage and Polyadenylation Factors
chemical_list: D015703:Antigens, CD; D015514:Oncogene Proteins, Fusion; D039221:mRNA Cleavage and Polyadenylation Factors; C479819:FIP1L1-PDGFRA fusion protein, human; D020796:Receptor, Platelet-Derived Growth Factor alpha