1349 A Rare Presentation of Cholecystogastric Fistula With Associated Mirizzi Syndrome Leading to the Diagnosis of Gallbladder Cancer

Abstract

INTRODUCTION: Biliary fistulas are a rare complication of gallstone disease. Technological advances have allowed for successful management & diagnosis. Mirizzi syndrome is a condition seen in less than 1% of patients with cholelithiasis & malignancy in 5 to 28% of cases. This is a rare presentation of coexistent Mirizzi syndrome and a cholecystogastric fistula leading to the diagnosis of gallbladder adenocarcinoma. CASE DESCRIPTION/METHODS: A 68 y/o female presented to the ER with complaints of jaundice & pruritis. Records demonstrated prior CTA&P with cholelithiasis with stranding & nonspecific stranding around the distal stomach. MRI w/wo contrast demonstrated loss of fat plane between gallbladder & stomach suggestive of fistulizing disease & a filling defect within the extrahepatic common hepatic duct related to external compression suggestive of Mirizzi Syndrome, no pneumobilia was seen. EGD/EUS was without direct visualization a fistulous tract, but revealed ulceration of gastric mucosa suggesting extrinsic pressure from a gallstone. ERCP demonstrated a stricture within the proximal CBD. Brushings were negative for malignancy. Lap chole revealed adherence of the stomach to the gallbladder fundus & takedown of cholecystogastric fistula was also performed. Histology from gallbladder specimen returned positive for invasive poorly-differentiated adenocarcinoma with transmural and lymphatic invasion. DISCUSSION: The presentation of cholecystogastric fistula generally includes pneumobilia & lacks pruritis suggestive of obstructive jaundice due to drainage of the biliary system via tract formation. Yet during the development of the fistulous tract the presentation varies quite drastically. Surgery is guided by the sub-classification of fistula formation/erosion as noted in the table figure. ERCP allows better characterization of the anatomy, in addition to offering the potential for therapeutic intervention with biliary decompression. There is an important known relationship between Mirizzi syndrome & gallbladder cancer likely related to the recurrent irritation occurring in the region along with chronic biliary stasis therefore frozen sections should be performed in all cases of Mirizzi syndrome to conclusively evaluate for gallbladder cancer. Our case highlights the malignancy potential within the presentation of fistulizing gallbladder disease. With a heightened index of suspicion and advancements in endoscopic and surgical techniques management of these patients will hopefully become less challenging.