S1792 Painless Obstructive Jaundice: Pancreatic Adenocarcinoma Cannot Be Excluded

Abstract

Introduction: Autoimmune pancreatitis (AIP) is a chronic inflammatory condition typically presenting with abdominal pain, jaundice and weight loss. AIP is an uncommon cause of pancreatitis and diagnosis may be challenging, but it is highly responsive to corticosteroids. We present a case of painless obstructive jaundice complicated by a mass on the pancreatic head. Case Description/Methods: A 57-year-old Indian male with no past medical history presented with vague abdominal pain, pruritus, and clay colored stools. Vital signs were unremarkable and laboratory investigations revealed alkaline phosphatase 515 U/L, alanine transaminase 732 IU/L, and total bilirubin 7.6 mg/dL. The patient underwent a right upper quadrant ultrasound which showed an enlarged gallbladder and dilated common bile duct (1.9 cm) down to the level of the pancreatic head. An endoscopic ultrasound (EUS) revealed a 3.2 x 3.7 cm hypoechoic mass in the head of the pancreas obstructing the bile duct, 2 enlarged lymph nodes in the area near the bile duct, marked bile duct dilation, and an enlarged sludge-filled gallbladder. Of note, unlike most ductal tumors the pancreatic duct upstream of the mass was not dilated. Fine needle aspiration (FNA) was unsuccessful due to the obstruction by the lymph nodes. Endoscopic retrograde cholangiopancreatography (ERCP) showed stricture of bile duct consistent with a pancreatic head mass, and was stented. Abdominal and pelvic computed tomography (CT) confirmed a 3 cm pancreatic head mass. Pathology result from the attempted FNA was inconclusive. Further labs revealed normal IgG4 and CA 19-9 level of 194; indicative of possible pancreatic malignancy. The patient developed jaundice, scleral icterus and rapid weight loss. EUS with FNA with repeat biopsies revealed rare degenerated epithelial cells. The patient was treated with high dose steroids, with planned pancreaticoduodenectomy. Follow-up CT revealed resolution of the pancreatic mass and was confirmed by repeat EUS/ERCP and normal CA 19-9 level. Discussion: Although painless obstructive jaundice with a pancreatic mass is a typical presentation for a pancreatic neoplasm; it is not the only possible diagnosis. Despite biochemical and radiographic evidence suggesting a malignancy; if AIP remains in the differential, a trial of steroids may be warranted to avoid unnecessary surgical intervention and associated morbidity.