situs inversus totalis ( sit ) is a rare congenital anomaly with an incidence of 1 in 10,00050,000 persons . sit refers to complete right - left transformation or a  mirror image  of the normal arrangement of body organs . the anatomic arrangement in a patient with sit is complete transposition of all viscera in the thoracic and abdominal cavities . although this condition does not affect normal health or longevity , its recognition is very important for treating many diseases , particularly those requiring surgical intervention . herein , we report a patient with gastric cancer and sit who was treated with radical subtotal gastrectomy . a 50-year - old man was admitted to our hospital for treatment of early gastric cancer ( egc ) , which was diagnosed during a screening esophagogastroduodenoscopy ( egd ) at a local clinic . his height was 171 cm , weight was 64.8 kg , and his body mass index was 22.2 . he had no anemia ( red blood cell count , 4.25  10/l ; hemoglobin , 13.4 g / dl ; hematocrit , 43.6% ) . the serum carcinoembryonic antigen concentration was not elevated ( 3.16 ng / ml ; reference range , 04.3 ) . a chest radiograph showed dextrocardia and a right subphrenic gas pattern in the stomach ( fig . 2 ) . abdominopelvic computed tomography ( ct ) showed complete transposition of the abdominal viscera , confirming sit ( fig . 3 ) . an f - fluoro2-deoxyglucose - d - glucose - positron emission tomography ( fdg - pet ) scan revealed no abnormal uptake and also noted a complete mirror image of the intrathoracic and abdominal viscera ( fig . 4 ) . we decided to perform a laparotomy and found complete transposition of the viscera ; the stomach and spleen were located on the right side of the abdomen , and the gall bladder , liver , cecum , and appendix were located on the left side . the macroscopic biopsy report revealed a 2.0  1-cm egc type iic located at the gastric angle with 2 and 6.8 cm proximal and distal safety margins , respectively . pathological examination showed tubular adenocarcinoma , moderately differentiated with depth of invasion into the muscularis mucosa . we followed the patient for 78 months in the outpatient department without recurrence of cancer . sit is transmitted as an autosomal recessive trait , but the exact genetic cause remains unknown . suggested that immobility of nodal cilia inhibits the flow of extraembryonic fluid during embryogenesis , leading to the development of sit . sit has various manifestations ; dextrocardia with complete reversal of the heart chambers can be seen . the stomach and spleen are located in the right side and the liver and gallbladder are located in the left side of the midline . cardiovascular abnormalities ( septal defects , pulmonary arterial stenosis , tetralogy of fallot , or transposition of great arteries ) and problems with the alimentary tract ( atresia or stenosis of the duodenum ) can also occur . no significant cardiac or respiratory abnormalities were detected in our patient at the preoperative screening . about 60% of patients with sit have other congenital anomalies of the gastrointestinal tract , including rotational anomalies , biliary atresia , splenic agenesis , small bowel atresia , duplication , and colon aganglionosis . the initial diagnosis and surgical intervention for diseases , such as cholelithiasis , reversed side liver dullness , an apical beat in the right fifth intercostal space , a chest radiograph revealing dextrocardia , and abdominal x - ray film demonstrating stomach gas on the right side can be diagnostic clues of sit . an fdg - pet scan was obtained as a whole body image in a single picture for the stomach cancer stage workup . many different cancers have been reported in patients with sit , including pancreatic , hepatocellular , colorectal , and gastric cancers . fabricus reported the first case of mirror image transposition in a man in 1600 [ 8 , 9 ] . allen   first reported a gastrectomy on a 30-year - old patient with gastric cancer and sit who died 3 weeks after surgery in 1936 . the symptoms of kartagener 's syndrome , including bronchiectasis , chronic sinusitis , and male infertility is a disease that is associated with sit . surgery in a patient with sit and gastric cancer could be difficult due to the anatomic anomalies , including perigastric major vessels . although the incidence of intra - abdominal malignancies in a patient with sit is very rare , the surgeon must anticipate the complexity of the surgical procedure in patients with sit and cancer . advanced surgical skill is required to perform a precise lymphadenectomy in a patient with sit by visualizing the exact mirror image of the anatomy during the operation . visualizing the mirror image of the anatomy therefore , preoperative recognition of the anatomic variations might be needed when operating on a patient with sit . it might be helpful to perform a three - dimensional ct angiography reconstruction prior to the operation . in conclusion , surgery in a patient with gastric cancer and sit can be safely performed by paying attention to the inverted anatomic structures during the operation . written informed consent was obtained from the patient for publication of this case report and any accompanying images .
situs inversus totalis ( sit ) is a rare congenital anomaly that refers to a completely reversed location of the abdominal and thoracic organs . 
 we report the case of 50-year - old man with gastric cancer and sit who was diagnosed during a screening esophagogastroduodenoscopy . a chest x - ray , abdominopelvic computed tomography , and 18f - fluoro2-deoxyglucose - d - glucose - positron emission tomography scans revealed sit . 
 we performed a radical subtotal gastrectomy with d2 lymph node dissection . 
 advanced surgical skill is required to perform a precise lymphadenectomy in a patient with sit by visualizing the exact mirror image of the anatomy during the operation . 
 the patient had an uneventful intra- and postoperative course and was followed up at the outpatient department without any evidence of recurrence . in conclusion , surgery in a patient with gastric cancer and sit can be safely performed by paying attention to the inverted anatomic structures during the operation .