Igg4 Related Disease of Skull Base-A Diagnostic Challenge

IgG4 related disease (IgG4-RD) is a fibro-inflammatory disease, with tendency to affect any organ of the body. However, few cases affecting the skull base have been reported in literature. We report one such case in an elderly male, who presented us with a mass lesion in the skull base that mimicked nasopharyngeal malignancy. On thorough clinical history, examination, and investigations, IgG4 Related disease was diagnosed and treatment was started for it. The patient responded well to the treatment and is on follow up.

IgG4-related disease: a complex under-diagnosed clinical entity

IgG4-related disease (IgG4-RD) encompasses a spectrum of complex fibro-inflammatory disorders which are often under diagnosed due to unfamiliarity by clinicians. A challenging multitude of clinical manifestations makes the diagnosis cumbersome. The primary clinical feature in IgG4-RD entails a tumor-like presentation coupled with tissue-destructive lesions. Histopathological findings include lymphoplasmacytic infiltrate, storiform fibrosis, and obliterative phlebitis. These findings, in combination with elevated serum immunoglobulin G4 levels, are diagnostic in the setting of single- or multi-organ involvement. A closer understanding of the role of T cells and B cells in the increased production of IgG4 has led to a notion that IgG4 can act as a pathogen, anti-inflammatory agent, or rheumatoid factor. Glucocorticoids are the primary treatment modality; however, relapse is common with prolonged therapy. Alternatively, immunomodulatory agents are being increasingly used as therapy. The aim of this article is to raise awareness of IgG4-RD and review the diagnostic algorithm, as IgG4-RD often mimics a wide array of clinical conditions. In addition, we summarize the pathogenesis and current treatment guidelines of IgG4-RD for clinicians. Awareness and accurate diagnosis are crucial in preventing progression to chronic diseases, thereby diminishing disease-related morbidity and mortality.