[A Case of Metastatic Small Intestinal Tumor Diagnosed with Intestinal Obstruction].

A 76-year-old man with a past history of liver transplantation because of liver cirrhosis visited a hospital in October 2018 because of vomiting and abdominal pain. Although the patient underwent conservative medical treatment, no improvement of the symptoms was observed, and he received consultation at our hospital. After thorough examination, and because of the policy of inpatient treatment after the diagnosis of adhesion ileus obstruction post liver transplantation surgery, intestinal decompression was performed using an ileus tube. However, there was no improvement in the symptoms even after inserting the ileus tube, and intestinal obstruction was diagnosed in November 2018. During the preoperative examination, a tumorous shadow was found in the right lung, although it became a policy of scrutiny after improvement of the bowel obstruction. During the laparotomy, a macroscopic tumor exposed on the serosal surface was observed on the anal side at 120 cm from the Treitz ligament, and this site was considered to be the blocking origin. Partial resection of the small intestine including the blockage site was performed. The pathological result revealed the diagnosis of adenosquamous carcinoma. Furthermore, immunostaining was CK7 positive, CK20 negative, TTF-1 negative, and Napsin negative, suggesting the possibility of a metastatic tumor derived from lung cancer. The postoperative course was uneventful, and the patient was discharged on postoperative day 9. On day 30 after surgery, the left pleural effusion increased and pleural effusion cytology revealed a diagnosis of primary lung adenocarcinoma Stage Ⅳ. Considering the patient's PS, it became a best supportive care(BSC)policy after consultation with the family, and it ended on postoperative day 70. Here, we report about a case diagnosed with metastatic small bowel cancer and intestinal obstruction and conduct a literature review.