Serous cystadenocarcinoma of the pancreas is a rare entity. We report a primary tumor of the pancreas in a 56-year-old woman that was histologically indistinguishable from microcystic adenoma, but which behaved in a malignant fashion. Metastatic lesions were found in the liver at the time of the initial operation. Nine years after the initial operation, new metastatic liver nodules were found, and the histologic characteristics of these lesions were quite similar to those of the pancreatic neoplasm. This is a very rare case which may support the existence of the entity, serous cystadenocarcinoma of the pancreas.