Resident Maimonides medical center, Brooklyn, New york Brooklyn, New York, United States
Disclosure(s):
Samridhi Lakhanpal, MBBS: No financial relationships to disclose
Introduction/Rationale: IgG4-related disease (IgG4-RD) is a rare, fibro-inflammatory, immune-mediated condition characterized by tissue infiltration of IgG4-positive plasma cells. It often mimics a wide range of conditions, such as autoimmune diseases (e.g., sarcoidosis, Sjogren's), infections (e.g., tuberculosis), fibro-inflammatory diseases, and malignancies. The varied presentation frequently causes diagnostic delays, emphasizing the importance of increased clinical awareness.
Methods: A 62-year-old male with a past medical history of sinusitis with sino-nasal surgery, pancreatitis was referred to the rheumatology clinic for evaluation of bilateral submandibular gland swelling with sicca symptoms and a dry cough. CT neck revealed symmetrical enlargement of the submandibular glands, bilateral hilar adenopathy. MRI abdomen revealed sclerosing cholangitis with biliary ductal dilatation, involvement of the distal stomach/duodenal bulb, soft tissue surrounding the aortic bifurcation and iliac arteries, and renal and pancreatic diffusion-restricting lesions consistent with autoimmune pancreatitis. Serology revealed IgG4 levels of 901.2, rheumatoid factor of 243, and low C3 and C4 levels. Serum protein electrophoresis showed a polyclonal pattern, with no definitive monoclonal gammopathy. Autoimmune serologies, including anti-ro, anti-la,antinuclear antibody, dsDNA, and angiotensin converting enzyme were negative. Core needle biopsy of the submandibular gland showed lymphoplasmacytic infiltrate consistent with IgG4-RD.
Results: The patient is started on 40mg prednisone daily with the plan of initiating rituximab.
Conclusion: This case highlights the diagnostic complexity of IgG4-RD and its ability to mimic a range of systemic diseases. In patients presenting with multiorgan inflammatory involvement and elevated IgG4 levels, IgG4 related disease should be promptly considered and confirmed with biopsy. Early recognition and corticosteroids initiation are crucial to prevent irreversible fibrosis and organ damage.
