Abdominal teratoma in a domestic duck.

Introduction: Teratomas are uncommon tumours of domestic fowl and have been reported rarely in ducks. The authors describe the histochemical (Masson's trichrome, PAS and Alcian blue stains), immunohistochemical and ultrastructural features of a multilobulated, mottled, abdominal mass (40 × 20 × 15 cm) found in a female white Pekin duck submitted for necropsy examination.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, S-100 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 tumour were consistent with a tridermic teratoma with a probable ovarian origin. Since clinical signs in this and other cases were minimal and the tumour is not usually diagnosed at an early stage of development, any surgical therapy often comes too late.[...]