Congenital fibropapillomatosis in a piglet.

We report a case of congenital fibropapillomatosis in the head and neck of a piglet from a swine breeding farm where sporadic cutaneous papillomas of the prepuce and scrotum had previously occurred in several boars. Histologically, the tumor consisted of multiple exophytic, papillary projections composed of branching, densely cellular, fibrovascular stalks covered by hyperplastic keratizing squamous epithelium. Ultrastructural examination failed to reveal viral particles. Cutaneous papillomatosis is rare in swine. To the best of our knowledge, this is the second report of congenital fibropapillomatosis in pigs.