Encephalocele in the ethmoid sinus presenting as a massive intracerebral hemorrhage after a "polypectomy": a case report.

The discovery of a congenital transethmoidal encephalocele in an adult patient is very rare and is sometimes misdiagnosed as a polyp of the ethmoid sinus. It is important to note that a congenital transethmoidal encephalocele presenting as a massive intracerebral hemorrhage in an adult patient has never been reported. This study's patient underwent endoscopic polypectomy and suffered from massive intracerebral hemorrhage because the encephalocele contained a frontobasal artery. Transcranial surgery was successfully performed to repair the frontal base. We report on the patient's condition and discuss the clinical implications of the present case.