A case of epithelioid glioblastoma with lung metastases in a young Cane Corso dog.

Astrocytomas are relatively common primary brain tumours of humans and companion animals. In dogs, they represent approximately 17-28% of primary central nervous system tumours. However, extracranial metastasis is extremely rare. This case report describes a grade IV astrocytoma (glioblastoma) in the cerebrum of a young Cane Corso dog with pulmonary metastases. The diagnosis was obtained via histopathological morphology and immunophenotyping, which showed strong positivity for glial fibrillary acidic protein, vimentin and connexin-43. The glioblastoma in this Cane Corso had epithelioid morphology with histological features of malignancy including high mitotic count, microvascular proliferation, serpentine necrosis and subventricular zone involvement. Epithelioid glioblastoma is a rare subtype that has only relatively recently been formally acknowledged in human medicine and it can also pose a diagnostic challenge in veterinary medicine.