We report a 53 years old male consulting for chest pain and dyspnea. On physical examination, an epigastric mass was detected. A TC scan showed a collection located in the omental bursa, which protruded over the posterior gastric wall and ascended to the mediastinum. Due to the presence of pancreatic calcifications, a pancreatic pseudocyst was suspected. The mediastinal cyst was drained percutaneously, leaving pig tail drainage in the cavity. Afterwards a cyst excision and Roux en Y gastrostomy was performed. After the surgical procedure the cyst became infected, requiring antimicrobials. After two weeks he was discharged in good conditions.