Uncommon Presentation of Immunoglobulin G4-related Disease as Multiple Skull Lytic Lesions

Abstract Immunoglobulin G4-related disease (IgG4-RD) typically affects the pancreatobilliary system and the head and neck. When it involves the skull, most cases reported involvement of the skull base and dural structures. IgG4-RD presenting as multiple skull lytic lesions is exceedingly rare. A 31-year-old male presented with multiple skull lytic lesions on X-ray and computed tomography, with magnetic resonance imaging revealing a contrast-enhancing extradural lesion in the left parietal region and surrounding edema. Surgical resection was performed, and histopathology confirmed IgG4-RD. The patient was treated with corticosteroids and is in remission, with regular follow-up for the same. IgG4-RD is an emerging condition that can involve the skull, often presenting as lytic lesions and highlighting a diagnostic challenge. Histopathology remains the gold standard, and early diagnosis is the key to remission and preventing systemic involvement.