Clinical, imaging and histopathological characteristics of a malignant intracranial meningioma with pulmonary metastasis in a dog

A 13-year-old Spanish Breton was presented for a hyperacute onset of dull mentation followed by a generalised tonic-clonic seizure and recumbency. An intracranial magnetic resonance imaging study identified a well-demarcated intraventricular mass, and cerebrospinal fluid analysis revealed moderate neutrophilic pleocytosis and proteinorrachia. A tentative diagnosis of meningioma was made and medical treatment was started. After a short initial improvement, the patient died 3 weeks later. Histopathology confirmed the presence of a malignant meningioma (World Health Organization grade III) and pulmonary metastasis. This is, to our knowledge, the first reported case of a canine intracranial meningioma with pulmonary metastasis showing magnetic resonance imaging and immunohistochemical characterisation of the tumour.