MRI diagnosis of meningioma with marked skeletal hyperostosis and parenchymal infiltration in a 6‐year‐old standard poodle

Abstract A 6‐year‐old, neutered, male standard poodle was presented for evaluation of behaviour change. Neurological examination was consistent with a prosencephalic lesion. A magnetic resonance imaging study of the brain revealed a large non‐uniformly enhancing, extraparenchymal mass (9.2 × 8.7 × 5.0 cm) compressing the underlying brain parenchyma with heterogeneous T2‐weighted, T2‐fluid‐attenuated inversion recovery and T1‐weighted intensities. A meningioma with severe secondary hyperostosis and parenchymal invasion was identified on postmortem histological evaluation. To the authors’ knowledge, the presence of marked hyperostosis and calvarial infiltration to this degree, as well as the magnetic resonance imaging characteristics of these changes, have not previously been described in canine meningioma.