Epidermal papilloma in a gold spot plecostomus (Pterygoplichthys joselimaianus Weber, 1991)

A neoplasia diagnosed as epidermal papilloma affecting a single aquarium fish (gold spot plecostomus Pterygoplichthys joselimaianus) is described. The fish had a dermal cauliflower-like mass on its lip. Histologically, the mass composed of extensive hyperplasia of the Malpighians cells, with papillary projections on fibrovascular stalks. Mitotic figure, koilocytes and individual cell necrosis were observed. This is the first report of epidermal papilloma in P. joselimaianus.