S3419 Beyond the Vessels: An Atypical Case of Takayasu Arteritis With Pancreatic Involvement

Introduction: Takayasu arteritis (TAK) is a large-vessel vasculitis primarily affecting the aorta and its major branches. Though classic symptoms include limb claudication, bruits, and diminished pulses, atypical systemic involvement can occur often delaying diagnosis. Abdominal organ involvement, especially pancreatic inflammation, is uncommon and underrecognized. Case Description/Methods: A 41-year-old woman with a remote history of steroid-treated aortitis presented with 2 months of epigastric pain with associated vomiting, chest tightness, and night sweats. Examination revealed diffuse abdominal tenderness, a soft systolic murmur, and no bruits or rashes. Labs showed normocytic anemia (Hb 9.9 mg/dl), mild thrombocytopenia (platelets 110 ×10⁹/L), elevated CRP (14 mg/L), but normal lipase (36 U/L), ESR, ACE, c-ANCA and IgG4 levels. ANA was low-titer positive (1:40; speckled pattern). Infectious workup, including syphilis and tuberculosis, was negative. A computed tomography abdomen and pelvis revealed diffuse inflammation within central aspects of the retroperitoneum, surrounding the pancreas, distal stomach/duodenum, aortitis and aneurysms in multiple arterial systems. These findings raised concerns for IgG4-related disease, systemic vasculitis (autoimmune or infectious), and malignancy, thus necessitating a tissue biopsy for further evaluation. Given the risk of inducing pancreatitis and associated complications, a pancreatic biopsy was not recommended. Cervical lymph node biopsy was then obtained which showed no evidence of infection, granulomatous disease or malignancy. Once infection was reasonably ruled out, empiric treatment with prednisone (20 mg daily) and azathioprine (50 mg daily) was initiated. Based on the American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria, the patient met diagnostic criteria for TAK. Subsequent PET-computed tomography demonstrated only minimal active inflammation at the takeoff of the brachiocephalic artery from the aortic arch. Steroids were discontinued and the patient was discharged on azathioprine 50 mg daily. Discussion: This case highlights an atypical presentation of Takayasu arteritis with involvement of the pancreas, distal stomach, duodenum and retroperitoneum similar to that of IgG4-related disease. Recognition of TAK in such atypical contexts is essential to guide timely immunosuppressive therapy and avoid delays in treatment.