Abstract The editors of this review have taken this opportunity to present a clinical case history of an obese young adult female patient who was found to have an 18mm in diameter pancreatic cyst. Prior to performance of bariatric surgery a CAT scan was performed which revealed the existence of the cyst. This case is being presented in order to answer some of the most frequently asked questions which arise when a pancreatic cyst is found incidentally. Keywords Pancreatic cyst. CAse report55 year old patient, female, with obesity grade III since she was 20 years old. Multiple complications: diabetes mellitus type 2, hypertension, sleep apnea-hypopnea and severe pul-monary hypertension. In pharmacological treatment with orlistat, thyroxine, metformin, enalapril and furosemide. In preoperative study for bariatric surgery is documented pancreatic cyst. In the physical examination the patient is in good general condition, obesity level III, body mass index of 37, with no other positive findings. Axial tomography of abdomen with contrast reported a small 18-mm simple cyst without intrinsic septa or solid component in the pan-creatic uncinate process.How Common is it to find A pAnCreAtiC Cyst? And, wHAt Are tHeir symptoms?In recent years radiological examinations have been per-formed more frequently, and we have also obtained a great improvements and better resolutions in these tech-niques resulting in diagnostic sensitivity. Together these have generated increased incidental findings of lesions in the pancreas. Large series using Computerized Axial Tomography (CAT) or Magnetic Resonance Imaging (MRI) have reported detection rates for pancreatic cystic lesions of between 1.2% and almost 20%. This is almost the same as the rate found in autopsies which can go up to 24.3% (1-3). Although the majority of these lesions are pseudocysts, a good portion of those found, between 10% and 15% of all these cystic lesions, are cystic tumors (4). Between 40% and 75% of pancreatic cystic tumors are asymptomatic when the lesion is incidentally diagnosed while searching for another condition. When these symp-toms appear, they are not generally very specific, but rather have vague indications such as slight abdominal pain, dis-tension and dyspepsia (5). In the case we analyzed we this is exactly what we found. In the study prior to bariatric surgery, we found a small cystic lesion in the CAT scan as an incidental finding, in a patient without symptoms.wHAt Are tHe possible differentil dignoses And tHeir CliniCAl relevne? (TABLe 1)The differential diagnoses for pancreatic cystic lesions are ample, and they are presented in two possible groups. On one hand there is a group of non-neoplastic lesions in