IgG4-Related Disease, the Malignancy Mimicker: Case Series from Bahrain

Area of Science:

• Immunology
• Pathology
• Rheumatology

Background:

• Immunoglobulin G4-related disease (IgG4-RD) is a complex immune-mediated condition characterized by IgG4-positive plasma cell infiltration and fibrosis.
• It unifies previously distinct idiopathic disorders like autoimmune pancreatitis and Mikulicz syndrome.
• IgG4-RD often presents as tumor-like masses, leading to potential misdiagnosis as neoplastic conditions.

Observation:

• This case series details four patients initially suspected of having cancer.
• These cases ultimately were diagnosed as IgG4-related disease, showcasing its diverse clinical manifestations.
• The study emphasizes the involvement of multiple organs and the protean nature of IgG4-RD.

Findings:

• The presented cases demonstrate that IgG4-related disease can mimic malignancies.
• Variable organ involvement and presentation are key features of this condition.
• Rituximab proved effective as a steroid-sparing immunosuppressant in managing IgG4-RD.

Implications:

• Accurate diagnosis of IgG4-related disease is crucial to avoid unnecessary oncological interventions.
• Understanding the varied presentations aids in earlier recognition and management.
• Rituximab offers a promising therapeutic strategy for IgG4-RD, potentially reducing steroid dependence.