1275 Intestinal-Type Intracholecystic Papillary Tubular Neoplasm (ICPN) Presenting as Acute Hemorrhagic Cholecystitis

Abstract

INTRODUCTION: The term Intracholecystic Papillary Tubular Neoplasm (ICPN) was coined by Adsay et al (2012). ICPN includes mass-forming (papillary or polypoid), intramucosal and preinvasive gallbladder neoplasms larger than one cm in size. CASE DESCRIPTION/METHODS: A 73-year-old man presented with acute and sharp right upper quadrant abdominal pain for one day. He denied nausea, vomiting, diarrhea, fever or chills. Past medical history included COPD, non-Hodgkin lymphoma in remission and hypertension. He was not receiving anticoagulants or antiplatelet medications. On abdominal examination, there was marked tenderness in the right upper quadrant area with a positive Murphy's sign. Laboratory testing revealed leukocytosis of 22,000/µL with neutrophilia and normal liver chemistry tests and a serum lipase level. Abdominal ultrasonography showed a markedly distended gallbladder with mural thickening of up to 1.0 cm and numerous gallstones with a positive sonographic Murphy's sign. Non-contrast CT showed mixed attenuation suggesting hemorrhage into the gallbladder lumen and suggestive of acute hemorrhagic cholecystitis. He underwent open cholecystectomy. Surgical findings were a distended gallbladder with a thickened and inflamed wall. Half of the gallbladder lumen was occupied by stones and the remainder was filled with detached, friable, tan-red hemorrhagic material. Microscopic examination of several of detached fragments and intact mucosa showed an abundant ICPN of intestinal-type origin and a tubular-papillary growth pattern. There was marked acute and chronic inflammation of the gallbladder wall without mural perforation. DISCUSSION: ICPNs are usually seen in middle-aged individuals, with a 2- fold higher prevalence in women. Macroscopically, ICPNs are exophytic tumors: tubular/lobulated types are soft, friable and can get easily detached appearing as sludge or debris, while granular or papillary types are sessile and feathery filling the gallbladder lumen. ICPN exhibits a variety of cell lineages such as biliary (50%), gastric (25%), intestinal (8%, as in our patient), oncocytic (6%) and mixtures of lineages (∼10%). In our patient, the two most plausible pathogenic processes are either diagnosis of an incidental ICPN due to the associated acute calculus hemorrhagic cholecystitis or acute “acalculous” cholecystitis from tumor shedding and bleeding into the gallbladder lumen and causing cystic duct obstruction associated with asymptomatic (incidental) cholelithiasis.