IgG4-Related Disease of Skull Base: Case Series of 3 Patients with Headache

Background: IgG4-related disease (IgG4-RD) is an immune-mediated, systemic, fibroinflammatory disease. IgG4-RD may manifest in almost every part of the human body. Here, we describe 3 patients with a skull base manifestation of IgG4-RD that mimicked malignancy. Case Description: Patient 1, a 73-year-old male, presented with a mass in the left nasopharynx and clivus. Patient 2, a 73-year-old male, presented with a mass in the left petrous bone and clivus with involvement of the left jaw joint. Patient 3, a 50-year-old male, presented with a lytic lesion of the clivus and sphenoid bone. All patients complained of headache and hearing loss. Serum IgG4 was normal, and imaging did not show systemic manifestation. Histology established the diagnosis of IgG4-RD. Two patients were treated successfully with prednisolone, hydroxychloroquine, and radiotherapy. One patient is monitored without treatment. Conclusions: The described cases emphasize the broad clinical spectrum of IgG4-RD. The diagnostic workup may be challenging, and serum IgG4 may be normal, as demonstrated in these cases. Careful histopathologic examination of the tissues remains essential. Timely diagnosis of IgG4-RD is important to prevent secondary organ damage in patients with active disease.