Description of a hamartoma-type odontoma in Angelfish (Pterophyllum scalare)

Abstract

Fish present the same variety of tumors as described in mammals and birds. Odontogenic tumors are related to alterations in epithelial and/or mesenchymal tissues involved in the formation and development of teeth. Histologically, the odontoma is a tumor characterized by abortive tooth formations and dental tissues (i.e. enamel, dentin, and cementum) that are normally formed but present a more or less disorganized pattern. In small fish species, odontogenic tumors have almost exclusively been described in angelfish (Pterophyllum scalare) and ocellaris clownfish (Amphiprion ocellaris). These tumors are macroscopically characterized as a nodular mass located in the frontal regions of the mouth. In angelfish these tumors have been described only as individual cases either as lip fibroma (in captive specimens) or as ameloblastoma (in wild specimens), but in this report we describe the occurrence of tumors in the frontal region of the mouth in a group of twenty aquarium angelfish.