Pathomorphological observations on epidermal papilloma of flatfish (Liopsetta obscura)
Fujimoto, Y.; Madarame, H.; Yoshida, H.; Moriguchi, R.; Kodama, H.; Iizawa, H.
Japanese Journal of Veterinary Research 34(2): 81-103
ISSN/ISBN: 0047-1917 PMID: 3723919 Accession: 006072852
Morphological investigation was carried out on 10 flatfishes (Liopsetta obscura) which were collected in Odaito, the eastern part of Hokkaido, and they were diagnosed as epidermal papilloma. Electron microscopically, the characteristics of so-called "X-cells" were clarified. They were considered as free cells which were completely different from epidermal cells and general inflammatory cells. Aggregation of fine hollow particles (ca. 30 nm) in the nucleus and particles enclosed by a double membrane with a central core in the cytoplasm were found in the X-cells. Numerous virus-like particles (ca. 100 nm) were found in the nuclei of the degenerative epithelial cells of the epidermis. Etiological relationship between epidermal papilloma and virus-like particles are not yet unknown and further investigations are needed.