Unresectable gallbladder carcinoma evolving into spontaneous cholecystocutaneous fistula: A case report and review of the literature

Introduction Spontaneous cholecystocutaneous fistula (SCF) is a rare complication of gallbladder disease in the modern era of early cholecystectomy. It usually results from neglected cholelithiasis or chronic cholecystitis. SCF secondary to gallbladder carcinoma is exceptional and indicates advanced disease. We report an unusual case of unresectable gallbladder carcinoma that evolved into a spontaneous cholecystocutaneous fistula, and review previously published cases. Case presentation A 65-year-old man with no significant medical history presented with abdominal pain, jaundice, and pruritus. Imaging revealed a gallbladder with lithiasis and a tight inflammatory stricture of the common hepatic and bile ducts. ERCP with stent placement was performed, followed by an attempted cholecystectomy. Intraoperatively, a stony mass involving the extrahepatic bile ducts, hepatic pedicle, gastric antrum, and colonic flexure was found, consistent with locally advanced gallbladder carcinoma. Resection was not feasible, and a hepatic biopsy confirmed metastatic well-differentiated adenocarcinoma of biliary origin. The patient received palliative GEMOX chemotherapy. Ten months later, he developed a subcostal swelling that revealed a subcutaneous abscess with a gallstone, consistent with a spontaneous cholecystocutaneous fistula. Surgical drainage achieved effective local control. At last follow-up (15 months after diagnosis), the patient remained alive under palliative management. Discussion SCF secondary to gallbladder carcinoma is extremely rare, with fewer than 10 cases reported. It occurs in the setting of locally advanced, unresectable disease. Diagnosis relies on multimodal imaging, while management is primarily palliative, as this condition typically arises in advanced, unresectable disease. Conclusion Spontaneous cholecystocutaneous fistula may represent a late and rare manifestation of advanced gallbladder carcinoma. Awareness of this complication may aid early recognition and appropriate management.