Isolated IgG4 hypertrophic pachymeningitis with cranial nerve involvement.

IgG4-related (IgG4-RD) disease is a relatively newly identified, chronic autoimmune disorder that can affect any organ system. The disease is relatively rare. It has mostly systemic presentation, however it can also appear in isolated form in one single organ. In our report, we demonstrate an elderly male patient’s case with IgG4-RD presented in the form of diffuse meningeal inflammation and hypertrophic pachymeningitis with one-sided cranial nerve and intraventricular involvement.