Secondary extracranial paranasal sinus meningioma in a dog

A 13-year-old Maltese dog was presented for inspiratory stertor. A computed tomography evaluation was performed and revealed an osteoproductive lesion primarily centered over the frontal bone with infiltration of the adjacent maxillary and nasal bones, focal intracranial invasion, and an associated broad-based, contrastenhancing, extra-axial lesion along the longitudinal cerebral fissure. Rhinoscopic and incisional biopsies of the paranasal mass were obtained, and a meningioma was diagnosed histologically. Based on the imaging features and histopathology results, an extracranial paranasal sinus meningioma was diagnosed in this dog. To the authors' knowledge, this is the first case report describing the computed tomographic findings associated with a secondary extracranial paranasal sinus meningioma in a dog. Key clinical message: Meningiomas in dogs can be present outside of the brain case and should be considered a differential for tumors of the paranasal sinuses.