S3408 Lung Adenocarcinoma Metastatic to the Gallbladder – An Unusual Presentation

Introduction: Adenocarcinoma is most common type of non-small cell lung cancer. Although metastasis to the bone and brain are common in patients with lung adenocarcinoma, metastasis to the liver is rare (around 3.5%) and associated with worst prognosis. We present an unusual case of metastatic adenocarcinoma of the lung to the gallbladder. Case Description/Methods: A 65-year-old man with a past medical history of right upper lobe lung adenocarcinoma stage pT4 N1 M0 diagnosed 5 years ago and treated with lobectomy with lymph node dissection and chemoradiation presented with right upper quadrant abdominal pain, nausea and vomiting. He was found to have elevated liver function tests with Bilirubin of 3.1 mg/dL, ALP of 346 Units/L, AST of 154 Units/L, and ALT of 256 Units/L. Abdominal ultrasound and magnetic resonance cholangiopancreatography (MRCP) revealed cholelithiasis, mild pericholecystic fluid with prominent central intrahepatic ducts and cut off at the hepatic hilum and small filling defects within extrahepatic ducts. Computed tomography chest revealed new bilateral pulmonary nodules raising concerns for metastatic disease. Patient underwent endoscopic ultrasound with findings of a 15 mm porta hepatis lymph node with fine needle aspiration negative for malignancy and no choledocholithiasis. Endoscopic retrograde cholangiopancreatography (ERCP) demonstrated normal caliber common bile duct with stricture at the common hepatic duct bifurcation and dilated intrahepatic ducts. The stricture was dilated with a 6 mm Hurricane balloon and a 10 Fr × 15 cm Johlin wedge stent was placed in the right intrahepatic duct. Brushings from the biliary stricture were negative for malignancy. Patient developed acute cholecystitis and underwent cholecystostomy tube placement complicated by bile leak requiring cholecystectomy. He had laparoscopic converted to open cholecystectomy due to significant perihepatic adhesions related to acute cholecystitis and leakage from the cholecystostomy tube. Pathology from the gallbladder revealed infiltrative cells with immunohistochemical staining consistent with metastatic pulmonary adenocarcinoma. The patient subsequently progressed with lung and liver metastatic disease and was transferred to hospice care. Discussion: To our knowledge this is the first reported case of lung adenocarcinoma metastatic to the gallbladder. The patient presented late, 5 years after the original diagnosis. Gallbladder metastasis needs to be considered in patients with metastatic lung adenocarcinoma presenting with acute cholecystitis or biliary obstruction.