A large convexity meningioma followed by liquorrhoea from a nasal encephalocele. A case report.

A 46-year-old woman was readmitted, two years after removal of a large convexity meningioma, because of cerebrospinal fluid rhinorrhoea from a nasal encephalocele eventually visualized by CT-scan. The encephalocele was extirpated via an intracranial approach, and its histological appearance is described. The aetiology of this extracranial brain tissue protrusion is discussed. It is suggested that the mechanisms behind the formation of this encephalocele are a combination of a congenital malformation and the long term increase of the intracranial pressure due to the meningioma.