A fibroepithelial tumor, probably caused by a herpes-type virus, found in juvenile, subadult, and adult sea turtles, causing them to be emaciated, weak, depressed, and anemic. Affected turtles may have flotation problems resulting from fibrous tumours in the lungs. Fibrous tumours are also found in visceral sites, such as liver, lung, kidney and gastrointestinal tract.