An abdominal teratoma in a domestic goose (Anseriformes,Anser anser domesticus)

Brain teratoma in a free-ranging mallard (Anas platyrhynchos) ˗ case report

ABSTRACT Teratoma is a rare neoplasia with differentiation in two or three germ cell lines. Intracranial teratoma in birds has rarely been reported, especially affecting the brain. This is the first report of a brain teratoma in a mallard with neurological clinical signs. The neoplasm was characterized as a mature brain teratoma, extending from the cerebellum to the brainstem, and with one nodule in the cortex.

Ovarian teratoma displaying a wide variety of tissue components in a broiler chicken (Gallus Domesticus): morphological heterogeneity of pluripotential germ cell during tumorigenesis

Spontaneous ovarian teratoma was found in a seven-week-old female Chunky broiler chicken that was slaughtered for food. On post-mortem inspection, a spherical tumor mass attaching to a juvenile ovary was found in the abdominal cavity. Histopathologically, the tumor was comprised of immature mesenchymal stroma and a variety of mature tissue elements of mesodermal and ectodermal origin. In addition, there were multiple indistinguishable tissue elements, which showed no malignant cytological features but were unidentifiable as to corresponding embryological layer of origin. These heterogeneous teratoma tissues consisted of a variety of glandular, cystic, duct-like, and tubular structures, some of which exhibited a lining by a mixture of both keratinizing/non-keratinizing stratified squamous epithelial cells and cuboidal/columnar epithelial cells. The ovarian tetatoma was considered a benign and congenital one. The highly diverse differentiation of the teratoma might have manifested a morphological aspect of intrinsic character of the pluripotential germ cells during tumorigenesis.

"TERATOCARCINOMATOSIS" IN AN EMU (DROMAIUS NOVAEHOLLANDIAE)

An adult female emu (Dromaius novaehollandiae) with no previous abnormal clinical signs was found dead in its stall. A postmortem examination revealed carcinomatosis of unknown origin. Histopathology identified the masses as teratomas with malignant transformation by the presence of poorly differentiated tissue and dissemination throughout the coelomic cavity. We propose a new term, "teratocarcinomatosis," for this finding. This is the first case of a reproductive tumor described in an emu and the first case of such marked spread of malignant teratomas in a bird.

Extragonadal teratoma in a domestic turkey (Meleagris gallopavo domestica)

This is the first report of a primary, spontaneous and, most probably, congenital teratoma in a domestic turkey, localized in front of the left eyeball. The unique localization allowed surgical excision of the tumour. The histopathological examination revealed that the tumour included structures derived from all three germ cell layers: ectoderm, mesoderm and endoderm (e.g. cartilaginous, osseous, haematopoietic, fibrous, nervous, glandular, squamous epithelial and smooth muscle tissues). The presence of epithelial cells as well as smooth muscle cells was confirmed using anti-cytokeratin and anti-desmin antibodies, respectively. The proliferative activity of the tumour cells was confirmed using proliferating cell nuclear antigen immunostaining. The other cases of teratoma in wild and domestic birds are reviewed briefly.

Teratoma in the cerebrum of a fantail pigeon

This is the first report of a primary teratoma in the cerebral cortex of a 1-year-old fantail pigeon and one of the few reports of intracranial teratomas in birds. The clinical signs were sudden onset of listlessness and a head tilt to the right. The right cerebral hemisphere contained an unencapsulated teratoma that included adipose, cartilaginous, fibrous and undifferentiated mesenchymal tissue as well as keratinized and glandular epithelial structures. Immunohistochemistry designed for mammals proved very useful and has been used to investigate the two germ cell lines, epithelial and mesenchymal, detected in the neoplasm. Indirect immunohistochemistry testing using vimentin, pancytokeratin, smooth muscle actin, neuron-specific enolase, and S-100 was done. Vimentin, smooth muscle actin and pancytokeratin immunoreactivity was strong. Neuron-specific enolase immunoreactivity was strongly positive in the normal brain adjacent to the neoplasm but there was no immunoreactivity within the neoplasm. Also, there was no S-100 immunoreactivity, suggesting that the mammalian proteins on which the immunohistochemistry is based are not present in pigeons.

Thoracic teratoma in a white Pekin duck (Anas platyrhinchos domesticus)

Teratomas are infrequent tumors in domestic fowl and have been rarely reported in ducks. It appears that the only case of mediastinal teratoma in a Pekin duck was observed by Alezais and Cotte in 1908. A lobulated, firm mass occupied the thorax of a 7-mo-old male white Pekin duck (Anas platyrhinchos domesticus). The tumor was composed of squamous epithelium, feather follicles, glandular epithelium, bone and cartilage, and thymus and was classified as tridermic, thoracic teratoma.