Submitted to: Merck Veterinary Manual
Publication Type: Book / Chapter
Publication Acceptance Date: May 7, 2008
Publication Date: November 1, 2010
Citation: Fadly, A.M. 2010. Neoplasms. In: Kahn, C. M., Line, S., editors. The Merck Veterinary Manual. 10th edition. Whitehouse Station, NJ: Merck & Co., Inc. p. 2449-2457. Technical Abstract: Depending on whether the etiologic agent is known, neoplasms of poultry are divided into 2 categories: virus-induced neoplasms and neoplasms of unknown etiology. There are 3 economically important virus-induced neoplastic diseases of poultry: Marek’s disease, caused by a herpesvirus, and avian leukosis/sarcoma and reticuloendotheliosis, caused by retroviruses. In addition to causing economic loss from tumor mortality as well as poor performance, some of these neoplastic diseases have served as highly suitable models for studying various phenomena of neoplasia. Indeed, medical research has found avian oncology an abundant resource. A rare neoplastic disease of turkeys known as lymphoproliferative disease that has been reported in Europe and Israel is induced by yet another retrovirus distinct from both the leukosis/sarcoma and reticuloendotheliosis viruses. The incidence of lymphoproliferative disease of turkeys has always been sporadic and is not discussed in this chapter. Neoplasms of unknown etiology are classified according to their morphologic characteristics; they include a wide variety of benign and malignant neoplasms. Of these tumors, dermal squamous cell carcinoma, multicentric histiocytosis, and adenocarcinoma are the most commonly seen in the field.