A teratoma in a Muscovy duck ( Cairina moschata )

Intracoelomic Teratoma in an Eclectus Parrot (Eclectus roratus)

A 26-year-old, male eclectus parrot (Eclectus roratus) was presented to its primary care veterinarian for a 10-day history of increased respiratory effort, lethargy, and a single episode of regurgitation. Hepatomegaly, proventricular enlargement, cranial displacement of the ventriculus, and coelomic effusion were suspected based on a 1-view radiographic image, and the patient was referred for further evaluation. On presentation to the referral veterinary hospital, a distended coelom and dyspnea with abnormal respiratory sounds were abnormalities noted upon physical examination of the patient. The bird was hospitalized for supportive care, and diagnostic tests were performed. Initial radiographic images at the referral hospital revealed a large intracoelomic mass. A computed tomographic scan was performed; however, the origin of the mass could not be determined. A fine-needle aspirate and cytologic evaluation of the intracoelomic mass revealed a neoplastic process but no specific tissue type. Two days after presentation to the referral hospital, an exploratory coeliotomy to surgically resect the mass was attempted. The mass occupied most of the coelomic cavity, with multiple adhesions to internal organs. The mass was successfully resected; however, the patient destabilized and died despite resuscitation efforts. Histopathologic examination of submitted tissue from the mass with immunohistochemistry revealed mixed populations of neoplastic cells differentiated from 3 primordial germinal layers, confirming the diagnosis of teratoma. Teratomas appear to be a rare tumor in avian species but should be included in a list of differential disease diagnoses for abnormal tissue masses of unknown origin. Only 2 cases of teratomas have, to our knowledge, been reported in psittacine species.

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.

Recurrent Subcutaneous Teratoma in an Adult Red-crowned Amazon Parrot (Amazona viridigenalis)

An approximately 42-year-old, wild-caught, red-crowned Amazon parrot (Amazona viridigenalis) was evaluated for a subcutaneous mass to the right of the keel. Cytologic examination of a fine needle aspirate of the mass were suggestive of granulomatous inflammation. The mass was surgically excised, and the parrot was treated with oral nonsteroidal anti-inflammatory drugs. Histologically, the mass was diagnosed as a teratoma with stratified squamous epithelial and neuroectodermal components. Tumor cells extended to surgical margins. Two years later, the neoplasm recurred, with regrowth of only the neuroectodermal component. The neoplasm was again removed surgically, but it recurred again 14 months later, necessitating a third surgery. Histopathologic examination confirmed recurrence of the original neoplasm in both instances, with incomplete margins on both excisions.

COELOMIC TERATOMA IN A BLUE-AND-YELLOW MACAW (ARA ARARAUNA)

A 2-mo-old, female blue-and-yellow macaw (Ara ararauna) presented with severe abdominal distension, pain, and respiratory distress. Ultrasonographic examination detected a heterogeneous mass with multiple anechoic areas, compatible with a multilocular cyst, occupying most of the coelomic cavity. Postmortem examination revealed a mass of 12.0 × 8.5 × 5.0 cm, which had an irregular surface and was connected by a pedicle to the ileum. This mass compressed and displaced the liver, proventriculus, gizzard, and intestines cranially to the left. The cut surface was lobulated, gray-white, mildly firm or soft, and was interspersed with multiple cysts filled with viscous and opaque liquid. Microscopically, it was composed of well- differentiated embryonic tissues from the endoderm, mesoderm, and ectoderm; therefore, it was diagnosed as a mature teratoma, which was theorized to have originated from Meckel's diverticulum. This study is the first, to the authors' knowledge to report a case of a teratoma in a blue-and-yellow macaw.

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.

Intracoelomic teratoma in a domestic duck (Anas platyrhynchos domesticus): a case report including immunohistochemistry and electron microscopy

A female domestic duck (Anas platyrhynchos domesticus) suddenly died with abdominal distension and a large multilobulated mass within the coelomic cavity was found. Histologically and immunohistochemically, a benign mature tridermic teratoma was diagnosed and epithelial structures, cartilage, bone, myxoid tissue, adipocytes, muscle cells, cystic spaces lined by squamous epithelium, feather follicles, melanocytes and variable neural and glial differentiation were recognized. By electron microscopy, desmosomes, keratin bundles, dense core neurosecretory granules, aberrant Z-line material and Luse bodies were found. To our knowledge, this is the first report of tridermic benign intracoelomic teratoma of a duck in which an extensive immunohistochemical and electron microscopic examination has been performed and in which a common neural and glial differentiation has been demonstrated.

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.