A rare gastric metastasis secondary to residual cystic duct carcinoma: case report and literature review

An unusual gastric metastasis from residual cystic duct carcinoma was reported, which was easily mistaken as primary gastric carcinoma before the surgery. A 50-year-old Chinese man presented with right upper abdominal discomfort. Based on the biopsy and computed tomography results, an advanced gastric antrum adenocarcinoma was primarily diagnosed. Intraoperatively, there were other findings: residual cystic duct with chronic hyperplasia, a suspected purulent cavity filled with grayish-brown cloudy liquid at the distal end of the cystic duct and the gallbladder socket. The patient underwent radical operation. Histopathological findings finally suggested that adenocarcinoma of the residual cystic duct infiltrated into the whole layer of the gastric wall. Postoperative adjuvant chemotherapy and immunotherapy were administered. The patient has achieved 20-month recurrence-free survival. The comprehensive treatment including radical surgery, adjuvant chemotherapy and immunotherapy may improve the prognosis of such patients.