Macrocystic serous cystadenoma of the pancreas masquerading as a mucinous cystadenoma: case report

Background: Pancreatic macrocystic serous cystadenoma is an uncommon benign lesion that can be misdiagnosed as a mucinous cystic neoplasm which, in turn, harbors malignant potential. We present the case of a patient with a pancreatic macrocystic serous cystadenoma and review current diagnostic modalities. Clinical case: We present the case of a 28-year-old otherwise healthy female who was incidentally found to have a pancreatic cyst. Computed tomography (CT) and endoscopic ultrasound (EUS) revealed a 3.0-cm lobulated and septated lesion in the head of the pancreas. Fine-needle aspiration (FNA) of the cyst revealed mucoid contents and a carcinoembryonic antigen (CEA) level of 0.69 ng/mL. The presumptive diagnosis of a mucinous cystic neoplasm was made and the lesion was resected by enucleation. Surgical pathology reported a 1.60-cm dominant cystic lesion lined with cuboidal epithelium and multiple adjacent microscopic satellite cysts, consistent with the macrocystic variant of the serous cystadenoma. Conclusions: Pancreatic macrocystic serous cystadenoma is uncommon and can be misdiagnosed as a mucinous cystic neoplasm. In order to make an accurate diagnosis and to select appropriate treatment, surgeons must be familiar with the current diagnostic modalities.