Pancreatic Serous Cystadenoma

Objective: To understand the natural history of serous cystadenoma. To understand the diagnostic accuracy of serous cystadenoma and identify possible factors that lead to the correct diagnosis. Summary Background data: Serous cystadenoma (SCA) is a benign cystic pancreatic neoplasm of the pancreas, accounting for approximately 15% of resected pancreatic cysts. Current recommendations are to proceed with surgical resection in symptomatic patients or when there is uncertainty regarding diagnosis. The latter continues to be a challenge since intentional resection of a serous cystadenoma account for only a minority of resected of cases. Methods: Retrospective single-institution review of patients who on final pathology had a diagnosis of pancreatic serous cystadenoma and of patients who had this diagnosis and were managed non-operatively. Demographic data, cyst characteristics, and growth rate were collected for analysis. Results: A total of 250 patients were analyzed. Median age was 62 (range 22 – 89), 65% were female, and 34% had symptoms. Tumor size ranged from 0.6 to 20, with a median of 3.4 cm. The morphological appearance was microcystic in 58%, macrocystic in 16%, mixed-type in 23%, and solid in 3%. Pancreatic duct dilation and pancreatic atrophy were found in 22% and 14%, respectively. The average growth rate was 1.8 mm/year regardless of tumor size. Of the 172 patients who underwent surgery, serous cystadenoma was the preoperative diagnosis in only 33%. A correct diagnosis was independently associated with large tumors and cyst fluid CEA analysis. Pancreatic duct dilation was independently associated with an in-growing cyst and presence of calcification. Conclusion: SCA is a slow-growing pancreatic cystic neoplasm that is mostly asymptomatic but can lead to pancreatic duct dilation and atrophy in some patients. A surprisingly small number of correct preoperative diagnoses confirms that this entity continues to be a diagnostic challenge. A more thorough preoperative workup that includes EUS should improve the rate of mis-diagnosis.