Abdominal teratoma in a domestic duck (Anas Platyrhynchos domesticus).

ntroduction: Teratomas are infrequent tumors in domestic fowl and have been rarely reported in ducks. The authors describe the histochemical (Masson trichrome, PAS, Alcian blue stains), immunohistochemical and ultrastructural features of a multilobulated, mottled, abdominal mass (40x20x15 cm) found in a female White Pekin duck submitted for necropsy.Results: The mass was composed of mature and embryonic tissues deriving from endoderm (intestinal- and respiratory- type epithelium, goblet cells, solid sheets of undifferentiated epithelial cells, tubular structures resembling renal tubules and glomeruli, immature glandular-like epithelium surrounding islands of immature cartilage), mesoderm (mature and immature cartilage, bone, myxoid tissue, adipocytes, smooth and skeletal muscle cells) and ectoderm (cystic spaces lined by squamous epithelium containing laminated and globular keratin, feather follicles, neurons, astrocytes, ganglion- like cells, melanocytes, undifferentiated small round cells). Immunohistochemistry revealed cytokeratin, desmin, smooth muscle actin, NSE, GFAP, S100 immunoreactivity of the different epithelial, mesenchymal and neuroectodermal components. Interesting ultrastructural findings were filaments with irregular masses of Z-line material and fibrous long- spacing collagens (Luse bodies).Conclusions: The morphological features of the tumor was consistent with a tridermic teratoma with a probable ovarian origin. Since clinical signs in this and other cases were minimal and the tumor is not usually diagnosed at an early stage of development, any surgical therapy often comes too late.[...