Histopathological and Immunohistochemical Studies of Spontaneous Rhabdomyosarcoma in Common Carp Cyprinus carpio

マゴイに自然発症した横紋筋肉腫の病理組織学的および免疫組織化学的研究

Histopathological and Immunohistochemical Studies of Spontaneous Rhabdomyosarcoma in Common Carp Cyprinus carpio

Creators Yasumoto Shinya

Creators Omura Takuya

Creators Nakamura Kazuya

Creators Kondo Masakazu

We examined in detail the pathological features of common carp Cyprinus carpio with spontaneous neoplastic lesions in the lateral muscle. Diseased fish had exophthalmos and dorsal enlargement along with a large oval tumor. Histopathologically, this tumor was mainly composed of parenchyma accompanied with central necrosis, and most of the tumor was covered with thin membrane containing collagenous fibers. However, this membrane was not observed at the deep area of the tumor where the tumor cells invaded into the muscular tissue. In the parenchyma, three types of cells were observed: Some rhabdomyoblast and multinucleated giant cells among the numerous PAS-positive tumor cells. Dissimilarity between the tumor and primary tissue suggest that the tumor is undifferentiated neoplasm. The tumor cell show positive reaction to vimentin but not to other antigens such as anti-Myogenin, anti-MyoD1 and so on. These findings indicate the tumor is rhabdomyosarcoma.

[ISSN]0370-9361