Laparoscopic Distal Gastrectomy for Synchronous Gastric Cancer and Gastrointestinal Stromal Tumor With Situs Inversus Totalis

Background: Situs inversus totalis (SIT) is a rare congenital condition in which the thoracic and abdominal organs are inverted like a mirror image. Case Report: We present a case of synchronous gastric cancer and gastrointestinal stromal tumor (GIST) associated with SIT in a 74-year-old man who was admitted to our department to treat gastric cancer. Esophagogastroduodenoscopy revealed a depressed lesion and a submucosal tumor (SMT) in the middle-third of the stomach. Abdominal contrast-enhanced computed tomography revealed complete inversion of the internal organs, and the common hepatic artery branched from the superior mesenteric artery. The patient underwent laparoscopic distal gastrectomy with regional lymph node dissection and Billroth I reconstruction. The macroscopic observation of the resected specimen revealed a depressed lesion measuring 2.0x1.5 cm in diameter and an SMT measuring 2.2x1.8 cm. Conclusion: Careful preoperative anatomic evaluation is important in SIT because the situs anomalies may be accompanied by major vascular anomalies.