| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Institute of Veterinary Pathology, Ludwig-Maximilians-University Muenchen, Munich, Germany (KB, WB, WH); Institute of Pathology, Technical University Muenchen, Munich, Germany (FF); Institute of Biology, University of Stuttgart, Stuttgart, Germany (SM); and Federal Research Centre for Virus Diseases of Animals, Riems Island, Germany (JPT)
This study documents the characteristics of a large series of spontaneously occurring thymomas in a laboratory colony of European hamsters (Cricetus cricetus). Thymomas are rare organotypic neoplasms originating from the thymic epithelial compartment. Because the hamster thymomas largely resembled their human counterparts, the recent World Health Organization (WHO) classification of human thymic epithelial tumors was used. Forty hamsters of both sexes aged 329 months were examined macroscopically and histologically. In 22 (55%) of the 40 animals, necropsy revealed enormous whitish masses in the anterior mediastinum, with a diameter ranging from 0.5 to 4.5 cm and a lobulated structure. The anatomy of the thymus region was normal in the remaining 18 hamsters. Histologically, the tumors presented as thymuslike organoid structures with areas of medullary and cortical differentiation and a predominance of lymphoid cells. A network of epithelial cells in the cortical areas, demonstrated immunohistochemically with a cross-reactive antibody against pancytokeratin, supported the diagnosis of thymoma. Cortical lymphocytes showed positive staining with cross-reacting antibodies against CD3 and terminal deoxynucleotidyl transferase, characteristic of immature T cells. On the basis of these findings, the tumors were classified as B1 thymomas, in some cases with AB or B2 components, according to the new WHO classification for human thymic epithelial tumors.
Key words: European hamsters; immunophenotyping; morphology; thymoma; WHO classification.
Request reprints from Dr. K. Brandes, Institute of Veterinary Pathology, Ludwig-Maximilians-University Muenchen, Veterinaerstrasse 13, 80539 Munich (Germany). E-mail: brandes{at}patho.vetmed.uni-muenchen.de
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |