Intracranial embryonal neoplasm in an alpaca

Area of Science:

• Veterinary Pathology
• Comparative Oncology
• Neuro-oncology

Background:

• Alpacas can develop various neurological conditions.
• Tumors affecting cranial nerves are uncommon in domestic animals.
• Vestibulocochlear nerve neoplasms present diagnostic challenges.

Purpose of the Study:

• To characterize a novel embryonal tumor affecting the vestibulocochlear nerve in an alpaca.
• To provide a detailed histopathological and immunohistochemical description of the neoplasm.
• To contribute to the understanding of rare tumors in camelids.

Main Methods:

• Necropsy and histopathological examination of a deceased alpaca.
• Immunohistochemistry (IHC) was performed on tumor tissue.
• Analysis of cellular morphology, mitotic activity, and stromal components.

Main Results:

• A multiphasic primitive cell neoplasm was found involving the right vestibulocochlear nerve.
• Histology revealed embryonal neuroepithelial and spindle cells with ependymal differentiation.
• Immunohistochemistry showed positivity for vimentin, MAP2, PGP9.5, synaptophysin, and cytokeratin AE1/3.

Conclusions:

• The tumor was diagnosed as a poorly differentiated embryonal tumor with ependymal differentiation.
• This represents a rare cranial nerve neoplasm in an alpaca.
• Further research is needed to understand the etiology and behavior of such tumors in camelids.