title: Differential diagnosis between undifferentiated tumor and thymoma by electron microscopy and immunohistochemical labelling.
abstract: This study of a particular case of tumor posed and resolved problems of differential diagnosis between an undifferentiated tumor and a thymoma by using electron microscopy in association with immunocytochemical methods. The first step was the distinction between an epithelial and a mesenchymal tumor, which was done by electron microscopy and immunofluorescence observation with anti-keratin antibody. The second step, a new approach to this problem, was the distinction between an epithelial tumor of thymic origin and another tumor located in the mediastinal lodge. A clear distinction was made by observation in immunofluorescence using anti-thymulin monoclonal antibody. This double approach permits differential diagnosis, excludes neoplasms of germ-cell origin, malignant lymphomas and leukemias, as well as mesenchymal tumors, and affirms the thymic origin of the tumor observed. A second type of cell observed in this tumor with a peculiar aspect, different from all types of epithelial cells observed in normal thymus, is discussed.
authors.affiliation: Inserm 25, UA 122 CNRS, Hôpital Necker, Paris, France.
authors.forename: B
authors.initials: B
authors.lastname: Nabarra
authors.forename: G
authors.initials: G
authors.lastname: Manganella
authors.forename: W
authors.initials: W
authors.lastname: Savino
mesh_terms: D003937:Diagnosis, Differential; D004848:Epithelium / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D013935:Thymic Factor, Circulating / Q000378:metabolism; D013945:Thymoma / Q000175:diagnosis* / Q000378:metabolism / Q000648:ultrastructure; D013950:Thymus Gland / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D013953:Thymus Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D013935:Thymic Factor, Circulating