The patients most likely have an infected pancreatic pseudocyst. Pancreatic Pseudocyst - MC cystic lesion of pancreas (75%) - It is a false cyst (Not lined by Epithelium, but with granulation tissue) - MCC of pseudocyst - Alcohol - MC site - Lesser sac - Pseudocyst can be seen in both Acute pancreatitis and Chronic pancreatitis but the difference is Pseudocyst are non-epithelialized fluid collection that can present at earliest 4 to 6 weeks after an episode of acute pancreatitis. The treatment of infected pancreatic pseudocyst is Similar to that for pancreatic abscesses i.e percutaneous catheter drainage with antibiotics. Aspiration of the fluid can be diagnostic but is not a definitive treatment, even with the addition of antibiotics. Internal drainage of pancreatic pseudocysts is contraindicated in the presence of infection but is the treatment of choice for mature, symptomatic, non-infected pseudocysts. Malignancy should be excluded if there is no preceding history of pancreatitis.