Whereas mucinous cystadenomas of the pancreas are considered premalignant, serous cystadenomas are believed to remain benign. We present a case of an 80-year-old woman with a primary tumor of the pancreas that was histologically classified as serous cystadenocarcinoma. Because preoperatively available criteria that determine malignancy in serous lesions are lacking, observation is the preferred option in serous cystadenomas. Operating every serous lesion is not justified. Reviewing all reports of serous cystadenocarcinomas that have been published to date, we are providing recommendations for the management of this rare entity.