title: Type B3 thymic epithelial tumor in an adolescent detected by immunohistochemical staining for CD5, CD99, and KIT (CD117): a case report.
abstract: A 16-year-old male patient was admitted to the hospital for a medical workup to examine an anterior mediastinal tumor in April 2000. A tumor excision and a right lower lung lobe nodule resection were performed in June 2000. The tumor tissue showed a cobblestone-like proliferation of atypical cells containing a discrete nucleolus that were aligned in an epithelial fashion against mainly lymphocytic inflammatory cells in the background; also shown were undifferentiated tumor cells with epithelioid characteristics. Immunohistochemical staining for CD5, CD99, and KIT (CD117) revealed that the tumor cells were CD5-negative and that some of the lymphocytes infiltrating the tumor tissue stained positive for CD99 and negative for KIT. The lesion was therefore diagnosed to be a type B3 thymic epithelial tumor.
authors.affiliation: Department of Surgery, Division of Thoracic Surgery, Nippon Medical School, Tokyo, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Yoshino
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Kubokura
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yamauchi
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Oaki
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Koizumi
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shimizu
mesh_terms: D000071443:12E7 Antigen; D000293:Adolescent; D015703:Antigens, CD / Q000032:analysis*; D018956:CD5 Antigens / Q000032:analysis*; D015815:Cell Adhesion Molecules / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis*; D013945:Thymoma / Q000276:immunology* / Q000473:pathology / Q000601:surgery; D013953:Thymus Neoplasms / Q000276:immunology* / Q000473:pathology / Q000601:surgery; D014057:Tomography, X-Ray Computed
chemical_list: D000071443:12E7 Antigen; D015703:Antigens, CD; D018956:CD5 Antigens; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; D019009:Proto-Oncogene Proteins c-kit