RESUMEN
BACKGROUND Duplication of the gastrointestinal tract is a rare congenital malformation that can develop in any part of the digestive tract. These duplications may be asymptomatic into adult age. Situs inversus totalis is a rare congenital anomaly characterized by a mirror transposition of thoracic and abdominal organs. We present a case of a pancreatic pseudocyst in a patient with a combination of situs inversus totalis and doubling of the esophagus, stomach, and first part of the duodenum. CASE REPORT A 64-year-old woman presented with epigastric pain. Abdominal computed tomography revealed a pancreatic pseudocyst and a previously identified duplication of the esophagus, stomach, and duodenum with situs inversus totalis. The patient underwent esophagogastroduodenoscopy (EGD) with endoscopic ultrasonography for pseudocyst drainage. During EGD, a bifurcation of the esophagus was found. Duplication of the esophagus, stomach, and first part of the duodenum was evident on further advancement. A week later, there was repeated filling of the pseudocyst with a liquid component, and the patient underwent cystogastrostomy with stenting. Five months after discharge, the stent was removed without complications. CONCLUSIONS Duplication of the gastrointestinal tract and situs inversus totalis are very rare congenital malformations that require early diagnosis. While situs inversus totalis does not represent any medical disadvantage, physicians should be aware of abnormal anatomy before procedures to prepare specialists for this in case of the need for special techniques. Endoscopic treatment of pancreatic pseudocysts is safe and effective even in such rare cases. The use of endoscopic methods also minimizes intervention and decreases the length of the patients' stays in the hospital.