Acute cholecystitis caused by gallbladder metastasis from non-small cell lung cancer: a case report.

Although non-small cell lung cancer can metastasize to any part of the body, metastasis to the gallbladder is extremely rare. We present a case of acute cholecystitis caused by gallbladder metastasis from non-small cell lung cancer. A 66-year-old man diagnosed with primary stage IV T4N3M1b non-small cell lung cancer was admitted to our hospital to receive chemotherapy, during which he presented with right upper abdominal pain. Abdominal contrast-enhanced computed tomography showed an enhanced mass at the neck of the gallbladder and gallbladder distension with obvious wall thickening. Acute cholecystitis caused by obstruction of the gallbladder neck by malignancy was suspected. Open cholecystectomy, extrahepatic bile duct resection, and Roux-en-Y choledochojejunostomy were performed. Pathological and immunohistochemical examinations revealed gallbladder metastasis originating from non-small cell lung cancer. In conclusion, when a patient with lung cancer presents with acute cholecystitis, the rare possibility of gallbladder metastasis should be considered.