Pancreatic cancer is a malignant neoplasm originating from transformed cells arising in tissues forming the pancreas. The most common type of pancreatic cancer, accounting for 95% of these tumors, is adenocarcinoma (tumors exhibiting glandular architecture on light microscopy) arising within the exocrine component of the pancreas.

A minority arise from islet cells, and are classified as neuroendocrine tumors. The signs and symptoms that eventually lead to the diagnosis depend on the location, the size, and the tissue type of the tumor, and may include abdominal pain, lower back pain, and jaundice (if the tumor compresses the bile duct), unexplained weight loss, and digestive problems.