What happened, in summary

A 53-year-old man was admitted in December 2014 with upper-abdominal bloating. CT showed thickening of the distal stomach and enlarged nearby lymph nodes. Imaging also confirmed situs inversus totalis, meaning his internal organs were arranged in a mirror-image pattern. Endoscopy found a 6-cm antral tumor, and biopsy showed gastric adenocarcinoma with a HER2 (C-erbB-2) score of 2+.

Because of the tumor size and enlarged lymph nodes, he received 2 cycles of preoperative oxaliplatin plus S-1 chemotherapy. In February 2015, he underwent fully robotic distal gastrectomy with D2 lymph-node dissection and Billroth II reconstruction. The surgical team adapted the port placement and dissection to his reversed anatomy. Pathology showed residual gastric adenocarcinoma involving the stomach wall, with 4 of 5 lymph nodes along the greater curvature involved.

He recovered quickly, was discharged on the fifth postoperative day, and began postoperative chemotherapy one week later. He completed 4 additional cycles of the same regimen. Two and a half years after surgery, no recurrence had developed.