Beware of Radiological Diagnosis of Pancreatic Pseudocyst: Lesson Learned From an Interesting Case.

Pancreatic pseudocysts are the most common cystic lesions of the pancreas; however, several cystic neoplasms may closely mimic their radiological appearance. Misdiagnosis may result in inappropriate drainage procedures and delayed definitive treatment. A case of pancreatic mucinous cystic neoplasm (MCN) that was repeatedly diagnosed as a pancreatic pseudocyst before definitive surgical management is presented. A 40-year-old woman with a history of acute pancreatitis presented with recurrent upper abdominal pain and a large pancreatic cystic lesion initially diagnosed as a pancreatic pseudocyst. She underwent endoscopic retrograde cholangiopancreatography (ERCP) with pancreatic duct stenting followed by cystogastrostomy. Despite these interventions, the lesion persisted. Contrast-enhanced CT (CECT) at Sri Ramachandra Institute of Higher Education and Research, Chennai, demonstrated a large cystic lesion in the body and tail of the pancreas with enhancing internal septations, raising suspicion for a cystic neoplasm. The patient subsequently underwent an open distal pancreatectomy with splenectomy. Histopathological examination revealed an MCN characterized by mucin-producing columnar epithelium and ovarian-type stroma, confirming the diagnosis. This case highlights the diagnostic challenges in differentiating pancreatic pseudocysts from MCNs based on imaging alone. Persistent or recurrent cystic lesions, particularly in middle-aged women and those demonstrating enhancing internal septations, should prompt reconsideration of the diagnosis and further evaluation to facilitate timely surgical management.