Spermatocytic seminoma with neuroectodermal differentiation and sertoli cell tumor in a dog.

Two distinct nodules developed in a cryptorchid testis of an 8-year-old male West Highland White Terrier. One nodule was a Sertoli cell tumor. The other was a spermatocytic seminoma with focal primitive neuroectodermal differentiation: formation of Homer-Wright rosettes and perivascular pseudorosettes, with immunoreactivity for S-100 protein, neuron-specific enolase, synaptophysin, neurofilament-68 kDa, microtubule-associated protein 2, and vimentin. The dog was alive and healthy 2 years after castration.

Bilateral intraocular malignant neuroectodermal tumors in a telescope goldfish (Carassius auratus).

Abstract A 5-year-old male telescope goldfish (Carassius auratus) developed buphthalmia of the left eye. An enucleation was performed and a diagnosis of a neuroectodermal tumor was made on histological examination. Although the fish initially recovered, it was killed 49 days postsurgery due to a severe decline in its condition. On histological evaluation of postmortem tissue samples, it was determined that the fish also had a neuroectodermal tumor of the right eye with local invasion of the brain. On immunohistochemistry, the neoplastic cells were positive for S-100. To the authors' knowledge, this is the first published case of naturally occurring bilateral intraocular neuroectodermal tumors in a fish.

Ependymoblastoma in a Japanese Black heifer.

An 18-month-old, Japanese Black heifer had ananastasia over a two-week period. The heifer was euthanized and necropsied. Grossly, a brown and soft mass was found in the left cerebellar hemisphere, which originated from the fourth ventricle in the pons. Multiple papillary masses were also found on the wall of the fourth ventricle. There was massive dilatation of the cerebral aqueduct, and also in the third and lateral ventricles. Histologically, the neoplastic cells formed numerous ependymoblastic rosettes and perivascular pseudorosettes. In the fourth ventricle, the normal ependymal cells were replaced by papillary proliferation of the neoplastic cells. Ultrastructually, the neoplastic cells had a feature differentiating to the ependymal cell showing a few basal bodies in the cytoplasm and connecting to adjacent cells with junctional complexes. We diagnosed the present case as ependymoblastoma with its origins in the fourth ventricle.

Primitive neuroectodermal neoplasia in coho salmon, Oncorhynchus kisutch.

Twelve coho salmon, approximately 8 weeks old, were each observed to have a single neoplasm involving the dorsolateral axial skeletal musculature. The neoplasm was closely associated with the vertebrae in all cases. The neoplasm was composed of islands containing small cells with round and occasional spindeloid morphology. Neoplastic cells had basophilic cytoplasm and vesicular nuclei. These cells exhibited immuno-positivity only for vimentin and S-100 protein. Ultrastructurally, neoplastic cells had nuclei with a predominance of euchromatin, cytoplasm containing marked amounts of rough endoplasmic reticulum, scant amounts of smooth endoplasmic reticulum, and scattered mitochondria. Rudimentary cell junctions were occasionally observed between adjacent neoplastic cells. Based on the close association of these neoplasms with the vertebrae as well as the histologic, ultrastructural, and immunohistochemical findings, these neoplasms were considered to all be primitive neuroectodermal neoplasms.

Cerebral primitive neuroectodermal tumour in a heifer.

A primitive neuroectodermal tumour (PNET) replacing the thalamus was discovered in an 18-month-old Prim'Holstein heifer. Microscopical examination of the tumour showed large sheets of densely packed cells with occasional Homer-Wright and perivascular rosettes. Neoplastic cells were small with ill-defined borders, scant cytoplasm and ovoid, irregularly shaped nuclei. Immunolabelling was positive for vimentin and neuron-specific enolase, in agreement with previous reports of PNETs in human beings and animals. This appears to be the first report of cerebral PNET in cattle.

Primitive neuroectodermal tumor in a two-month-old black and white Colobus monkey.

A 2-month-old male black and white Colobus monkey (Colobus guereza kikuyuensis) was euthanatized because of progressive physical deterioration, rear limb paralysis, lymphadenopathy, and the presence of facial and retroperitoneal lumbar masses. At necropsy, soft white masses were present in and around lumbar vertebrae, the subcutis of the face, multiple lymph nodes, and the fourth ventricle of the brain. Histologic and immunohistochemical analysis of these masses revealed a primitive neoplasm with both neuronal and glial differentiation, consistent with a primitive neuroectodermal tumor (PNET) with bipotential differentiation. The extracranial tumors were synaptophysin (SYN)-positive, glial fibrillary acidic protein (GFAP)-negative, and neurofilament protein (NFP)-negative, while the intracranial tumor was SYN-positive, GFAP-positive, and NFP-negative.