Feline uveal melanomas induced with feline sarcoma virus: potential model of the human counterpart.

Uveal melanomas were produced by injecting Gardner strain feline fibrosarcoma virus intraocularly into 10- to 15-day-old noninbred kittens. Tumors developed in about 90% of the cats' eyes receiving virus. Progressing tumors (62 eyes of 36 cats) began as small hyperpigmented lesions at the site of injection and grew to fill the anterior chamber by 3-5 months after infection. About 30% of cats with these tumors developed secondary tumors and died. Nonprogressive tumors characterized by flat, pigmented plaques on the iris at the site of injection developed in 25 eyes of 18 cats. These lesions did not enlarge except in proportion to the growth of the eye. Tumors were composed of pigmented spindle cells, pigmented epithelioid cells, and nonpigmented spindle cells. The cells could be grown for 5-8 passages in vitro. One culture assumed a transformed morphology and grew in noninbred athymic nu/nu mice. The lesions resembled human spindle cell melanomas.