Although many have lumped nearly 20 different neoplasms under the umbrella term "cancer of the pancreas," each of these neoplasms is pathologically and clinically distinct. In addition, each may require a specific treatment and result in a different outcome. Understanding the pathology of pancreas cancer, therefore, forms the cornerstone for rational treatment and prognostication. This article describes the pathology of a number of primary, metastatic, and systemic cancers that can involve the pancreas. The clinical relevance of each gross and histologic tumor feature is emphasized.