Abstract

Immunoglobulin G4–related disease (IgG4-RD) presents diversely and can affect almost any organ system, yet direct brain parenchymal involvement is not described frequently in the literature. This case outlines the successful treatment of IgG4-RD manifesting as an enhancing left temporal mass in a man in his late 60s who presented with the symptoms of confusion and headaches. A full recovery was achieved with steroids and rituximab, underscoring the importance of recognizing brain involvement in IgG4-RD and the potential for treatment success with this regimen.