S1660 Granulomatosis With Polyangiitis Presenting as Pancreatic Mass

Abstract

Introduction: Granulomatosis with polyangiitis (GPA) is a small and medium vessel vasculitis that affects mostly the pulmonary and renal system. GI involvement in GPA is uncommon and involvement of the pancreas is rare. Our case adds to the limited existing literature on pancreatic involvement in patients with GPA. Case Description/Methods: We report the case of a 41-year-old female with a past medical history of hearing loss, recurrent otitis media, mastoiditis who presented with fever, nausea, vomiting, abdominal pain radiating to the back, generalized body aches, and weakness which has been ongoing for about 4 months. On exam, she had tenderness over the right mastoid, a benign abdominal exam, and bilateral lower extremity skin nodules and ulcerations. Initial lab tests showed cell counts and basic chemistries within normal limits, an ESR of 104, CRP of 271, and a normal lipase. Her ANA IgG was 0.90, serine proteinase 3 was 26, and C-ANCA was positive. Tuberculosis and cocci as well as CEA and CA 19-9 were negative. CT Chest showed two pulmonary nodules at the right lower lobe. CT Abdomen and Pelvis showed an edematous mass-like enlargement of the pancreatic body and tail with decreased enhancement, spanning 4.0 x 9.4 x 3.7 cm. The patient underwent Endoscopic Ultrasound with Fine Needle Biopsy of the pancreatic lesion and histopathology showed granulomatous disease. She was started on steroids and repeat imaging 2 months later showed resolution of lung nodules and a significant reduction in the mass like enlargement of the pancreatic body and tail. Discussion: There have been case reports on GPA involving the GI tract presenting as acute pancreatitis or a pancreatic tumor. A literature review shows 12 published reports of pancreatic involvement in patients with GPA. Of these 12 cases, 7 presented as pancreatic tumors or lesions. A review of these cases shows that steroids or immunosuppressive therapy have been used with good clinical improvement. In addition, three of these reports did initially have pancreatic surgery for presumed pancreatic malignancy, only to later have a histopathological diagnosis of GPA. These patients did not have typical clinical features of the disease. This presents a diagnostic challenge as pancreatic manifestation of this disease is uncommon and can result in invasive surgical intervention if mistaken as a primary malignant process. Prompt recognition of GPA involving the pancreas can improve outcomes as it can progress to multiorgan involvement if the diagnosis is delayed.