BackgroundSurgical resection of gallbladder cancer with negative margins is the only potentially curative therapy. Most patients with gallbladder cancer are diagnosed in an advanced stage and, despite the availability of several chemotherapies, the prognosis remains dismal. We report a case of locally advanced gallbladder cancer that was successfully treated with effective cisplatin plus gemcitabine, followed by curative resection.Case presentationA 55-year-old Japanese female was hospitalized with right hypochondrial pain. Enhanced computed tomography revealed a 49 × 47 mm mass at the neck of the gallbladder, with suspected invasion of the liver and right hepatic artery. Endoscopic retrograde cholangiopancreatography demonstrated displacement of the upper bile duct. Intraductal ultrasonography showed irregular wall thickening and disappearance of the wall structure in bile ducts from the B4 branch to distal B2 and B3. Percutaneous transhepatic biliary biopsy revealed a poorly differentiated carcinoma. The patient was diagnosed with unresectable gallbladder cancer (T4N0M0 stage IVA). Cisplatin plus gemcitabine chemotherapy was initiated. After six courses of chemotherapy, enhanced computed tomography showed that the mass in the neck of the gallbladder had shrunk to 30 mm, Endoscopic retrograde cholangiopancreatography showed improvement of the hilar duct stenosis. A biopsy of the bile duct mucosa showed no malignant cells in the branch of the left and right hepatic ducts, the left hepatic duct, or the intrapancreatic ducts. The patient underwent conversion surgery with right and segment 4a liver resection, extrahepatic duct resection, and cholangiojejunostomy. The histopathologic diagnosis showed that the tumor cells had shrunk to 2 × 1 mm, and that R0 resection of the T2aN0M0 stage IIA tumor was successful.ConclusionAlthough conversion surgery for gallbladder cancer is rarely possible, curative resection may offer a better prognosis, and it is important to regularly pursue possibilities for surgical resection even during chemotherapy.