Evidence suggests that pancreatic cancer is linked to inhalation or absorption of carcinogens that are then excreted by the pancreas. Examples of such carcinogens include:

Other possible predisposing factors include chronic pancreatitis, diabetes mellitus, and chronic alcohol abuse.

Tumors of the pancreas are almost always adenocarcinomas. They arise most commonly (67% of the time) in the head of the pancreas. Tumors in this location commonly obstruct the ampulla of Vater and common bile duct and metastasize directly to the duodenum. Adhesions anchor the tumor to the spine, stomach, and intestines.

Less commonly, tumors arise in the body and tail of the pancreas. When this happens, large nodular masses become fixed to retropancreatic tissues and the spine. The spleen, left kidney, suprarenal gland, and diaphragm are directly invaded, and the celiac plexus becomes involved, resulting in splenic vein thrombosis and spleen infarction. Among the rarest of pancreatic tumors are islet cell tumors. (See Islet cell tumors.)

In pancreatic cancer, two main tissue types form fibrotic nodes. Cylinder cells arise in ducts and degenerate into cysts, and large, fatty, granular cells arise in parenchyma.

Related to the progression of the disease, complications may include malabsorption of nutrients, type 1 diabetes, liver and GI problems, and mental status changes.

A patient who seeks treatment early in the disease usually reports a dull, intermittent epigastric pain. Later, he may report continuous pain that radiates to the right upper quadrant or dorsolumbar area. He may describe it as colicky, dull, or vague and unrelated to posture or activity, or he may state that meals seem to aggravate the epigastric pain. He may also report anorexia, nausea, vomiting, and a rapid, profound weight loss.

Inspection may reveal jaundice. On palpation, you may note a palpable, well-defined, large mass in the subumbilical or left hypochondrial region—an indication that the tail of the pancreas is involved. The mass may adhere to the large vessels or the vertebral column and may produce a pulsation. If the tumor has involved or compressed the splenic artery, auscultation of the left hypochondrium may reveal an abdominal bruit.

Several tests may be ordered to help diagnose the disease and determine its extent.

Percutaneous fine-needle aspiration biopsy of the pancreas may detect tumor cells, and laparotomy with a biopsy allows a definitive diagnosis. However, a biopsy may miss relatively small or deep-seated cancerous tissue or create a pancreatic fistula. Retroperitoneal insufflation, cholangiography, scintigraphy and, particularly, barium swallow (to locate the neoplasm and detect changes in the duodenum or stomach relating
to cancer of the head of the pancreas) also can be performed to detect the disease.

Ultrasonography helps identify a mass but not its histology. A computed tomography scan shows greater detail of the mass than ultrasonography. Magnetic resonance imaging discloses the tumor’s location and size in great detail.

Angiography reveals the tumor’s vascular supply. Endoscopic retrograde cholangiopancreatography allows visualization, instillation of contrast medium, and specimen biopsy.

A secretin test reveals the absence of pancreatic enzymes and suggests pancreatic duct obstruction and tumors of the body and tail.

Other laboratory tests that support the diagnosis include: