Anaplastic Carcinoma Possibly Arising from a Heterotopic Pancreas

Anaplastic carcinoma is a rare pancreatic cancer, and the malignant transformation of a heterotopic pancreas is also rare. We herein report a case of an elderly woman with a mass of unknown origin in the abdominal cavity. Computed tomography identified the extent of the tumor but not the organ of origin. The abdominal tumor eventually metastasized to the liver and lung. An autopsy and immunohistochemical examination revealed an anaplastic carcinoma possibly originating in an ectopic pancreas.