DAO 24:227-232 (1996)  -  doi:10.3354/dao024227

Invasive walleye dermal sarcoma in laboratory-maintained walleyes Stizostedion vitreum

Earnest-Koons K, Wooster GA, Bowser PR

Walleye dermal sarcoma (WDS) was first described as a multifocal cutaneous neoplasm of walleyes Stizostedion vitreum in Oneida Lake, New York, USA. The neoplasm was subsequently shown to be caused by a type C retrovirus. We have successfully transmitted the neoplasm in laboratory-maintained young-of-the-year (YOY) walleyes in a number of pathogenesis studies over the past 6 yr. Neoplasms in these laboratory trials were typical of those superficial neoplasms observed in adult feral walleyes. A transmission study was begun summer 1994 using 9 wk old walleyes. Starting at 56 d and continuing throughout the experiment, injected fish developed grossly visible, multiple small white skin masses that varied from 0.5 to 10 mm in diameter. These masses appeared on the skin of the head, back, flank, fins and lips. Histopathological examination revealed that some of these neoplasms, especially those collected at 84 d and beyond, did not remain cutaneous, but were locally invasive and replaced normal tissue, primarily muscle. One neoplasm on the head of a young walleye had deformed the brain and had invaded the skull. Due to the unusual invasive nature of the microscopic lesions of the neoplasm, these findings are reported.


Walleye . Stizostedion vitreum . Neoplasia . Retrovirus . Transmission . Virus associated tumors . Dermal sarcoma


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