[A case of perforated gastric cancer in which complete response was confirmed with resection following TS-1/CDDP combined chemotherapy after omentopexy].

The present patient was a 50-year-old male with sudden upper abdominal pain. The patient exhibited pallor, and physical examination revealed a rigid abdomen. Abdominal x-ray revealed free air, and emergency laparotomy was performed to confirm upper gastrointestinal tract perforation. A perforated lesion of approximately 1 cm in diameter was found on the anterior wall at the gastric angle. The area surrounding the lesion was tumor-like, and the posterior wall was fused invasively with the pancreas. Malignancy was suspected; however, considering the patient's general status, greater omentum grafts were opted for. The patient was diagnosed with type III gastric cancer by gastroendoscopy post-operatively, and TS-1/CDDP therapy was started on the 28th day after surgery. After three courses of treatment, the tumor was found to have smoothened, wall consolidation was improved, and a second surgery was performed. During laparotomy, a nodule in the round ligament of liver was found and removed; however, there were no other medical findings that raised suspicion of peritoneal dissemination or liver metastasis. It was concluded that radical surgery was possible, and distal gastrectomy (D 2) was performed. Pathological examination revealed that signet ring cell carcinoma was present on only part of the mucous membrane. The lower and muscle layers of the serous membrane and the nodule in the round ligament of liver were replaced by fibrous tissue, indicating the disappearance of cancer cells. Two years and three months after surgery, the patient exhibited no signs of recurrence.