[Rosette-forming glioneuronal tumor of the fourth ventricle. Case report and literature review].

Introduction: Rosette-forming glioneuronal tumor (RGNT) of the fourth ventricle is a rare tumor that has been recently characterized. RGNT was included as a new glioneuronal tumor in 2007 by the World Health Organization (WHO) in classification of tumors of the central nervous system. Within this group we found 34 documented cases.

[Chronic hypertrophic pachymeningitis: 2 clinical cases are presented].

Chronic hypertrophic pachymeningitis is an inflammatory process of unknown aetiology characterised by a thickening of the dura mater causing pseudotumoural growth. Clinical manifestations are usually secondary to compression of adjacent neurological structures but may be also secondary to inflammatory processes. Diagnosis is mainly obtained by excluding infectious, neoplastic and autoimmune causes.

Severe intraoperative air embolism during convexity meningioma surgery in the supine position. Case report.

Background: Acute venous air embolism (AE) is a well-known intraoperative complication of neurosurgical procedures, especially during surgical procedures performed in the sitting position, but it is a rare complication in the supine position. A case of a patient who developed an AE during a supratentorial craniotomy in the supine position is presented and the literature is reviewed.

Case Description: A 45-year-old man had a large left frontal convexity meningioma.