[Hypertrophic pachymeningitis secondary to IgG4-related disease: case report and review of the literature].

Introduction: Hypertrophic pachymeningitis is an infrequent disorder that produces focal or diffuse thickening of the dura mater. It can be idiopathic or secondary to infectious, autoimmune or neoplastic processes. The recently described 'IgG4-related disease' could be the cause of many cases considered cryptogenic.