Mucinous Cystic Neoplasm Coexisting With a Pancreatic Pseudocyst

We report the case of a 45-year-old woman who presented with abdominal pain and distension and was initially diagnosed with a pancreatic pseudocyst. She underwent endoscopic ultrasound (EUS)-guided cystogastrostomy. Biochemical analysis of the cyst fluid revealed elevated carcinoembryonic antigen. Due to persistent symptoms and cyst fluid findings suggestive of mucinous pathology, she subsequently underwent distal pancreatectomy with splenectomy. Histopathology revealed a mucinous cystic neoplasm (MCN) coexisting within a pseudocyst. The patient had an uneventful postoperative recovery and is doing well on follow-up.