Gizzard adenocarcinoma in an aged Humboldt penguin (Spheniscus humboldti)

Optic nerve meningioma and cloacal adenocarcinoma in a Humboldt penguin

A 26-y-old, male, captive Humboldt penguin (Spheniscus humboldti) was euthanized following a 3.5-mo history of weakened elimination mechanics, recurrent tenesmus, intermittent hemorrhagic droppings, and a cloacal mass. Blepharospasm, of unknown cause, of the right eye was present for ~3 mo before euthanasia. Autopsy revealed a cloacal adenocarcinoma with localized coelomic carcinomatosis and distant metastases to the liver and lungs. On histopathology, a 2.6 × 1.2 × 0.5-mm, well-demarcated mass was found surrounding the right optic nerve, expanding the subdural space and wrapping the leptomeninges. The mass was composed of neoplastic spindle-to-polygonal cells consistent with a meningioma, meningothelial subtype. No evidence of neoplasia was found in the optic chiasm or brain, indicating a primary retrobulbar meningioma. Immunohistochemistry for cytokeratin AE1/AE3, vimentin, and S100 revealed robust and consistent immunoreactivity to vimentin, and weak and variable immunoreactivity to cytokeratin and S100, supporting the diagnosis. Meningiomas have been described only rarely in avian species, and we found no reports of optic nerve meningiomas in any avian species to date. The optic nerve meningioma in this case was considered a clinically incidental finding.

Solitary adenoma in the proventriculus of a budgerigar (Melopsittacus undulatus) diagnosed by immunochemistry - short communication

The authors describe a solitary adenoma in a 5.5-year-old female Budgerigar (Melopsittacus undulatus). The tumour was partially blocking the lumen of the proventriculus and filled it almost completely. Decreased passage of food towards the gizzard and the intestines developed in the bird as result of the obstruction, which periodically hindered the passage, leading to slow emaciation. An epithelial tumour composed of irregular glandular acini was diagnosed by histological examination. Immunohistochemical reaction with pancytokeratin showed a positive cytoplasmic reaction both in the neoplastic and the normal glandular structures.