S5514 Rare Extrahepatic Biliary Obstruction Caused by a Common Lesion: A Large Simple Hepatic Cyst

Introduction: Hepatic cyst can be asymptomatic or present with sensation of an upper abdominal mass, abdominal discomfort, and anorexia. Mass effect of intrahepatic hepatic biliary obstruction secondary to hepatic has been reported in literature previously, however extrahepatic biliary obstruction is extremely rare. Herein, we describe this rare presentation of both intrahepatic and extrahepatic biliary obstruction secondary to a large hepatic cyst. Case Description/Methods: An 83-year-old woman with no significant past medical history presented for abdominal pain secondary to right upper quadrant mass. Computed tomography abdomen demonstrated a large cyst (13.9 × 10.6 × 15.8 cm) in the liver with thin internal septation. It was associated with mild intrahepatic biliary dilation which is likely secondary to mass effect from the large cyst. The patient underwent percutaneous drainage of the cyst with removal of 1.1 L fluid. The pathology was negative for malignant cells; numerous macrophages, amorphous debris and brown pigment noted. In less than 1 month, she redeveloped the large hepatic cystic lesion measuring up to 17 cm. The mass effect from the cyst during the second presentation caused intra as well as extra hepatic biliary dilation. She underwent repeated percutaneous aspiration of the hepatic cyst, yielding 1.2 L of bilious fluid with the drainage catheter left in place to prevent recurrence. Discussion: This case aims to highlight a rare complication of hepatic cyst i.e. biliary obstruction. Usually, hepatic cysts are benign and managed conservatively. However, cysts >10 cm in size have been reported to cause biliary obstruction. Few of these large hepatic cysts causing biliary obstruction also run a risk of being complicated by acute cholangitis delaying surgery until stabilization. Our patient presented with a hepatic cyst that was up to 17 cm in size and caused not only intrahepatic, but also extrahepatic biliary obstruction. Although she presented with a simple cyst, it is also important to consider and rule out more complex cystic lesions such as biliary cystadenoma or cystadenocarcinoma, which may present similarly but require oncologic resection. This case reinforces the importance of considering compressive hepatic cysts in the differential diagnosis of obstructive jaundice, particularly in the absence of more common etiologies.