Autoimmune pancreatitis (AIP) is difficult to diagnose. Often, it doesn't cause any symptoms. When it does, its symptoms and signs are very similar to those of pancreatic cancer.

Pancreatic cancer symptoms can include:

  • Dark urine
  • Pale stools or stools that float in the toilet
  • Yellow skin and eyes (jaundice)
  • Pain in your upper abdomen or middle part of your back
  • Nausea and vomiting
  • Weakness or extreme tiredness
  • Loss of appetite or feelings of fullness
  • Weight loss for no known reason

The most common sign of autoimmune pancreatitis, present in about 80 percent of people, is painless jaundice, caused by blocked bile ducts. AIP can also cause weight loss. Many people with autoimmune pancreatitis have masses in the pancreas and other organs, which can be misdiagnosed as cancer.

The two types of AIP occur with different frequency in different parts of the world. In the United States, about 80 percent of people with autoimmune pancreatitis have type 1.

People with type 1 autoimmune pancreatitis often:

  • Are over age 60
  • Are male
  • Have multiple organ involvement including the bile ducts (IgG4-related sclerosing cholangitis), the salivary glands (IgG-related sialadenitis), or the lungs (IgG4-related pulmonary disease)
  • Have retroperitoneal fibrosis (RPF), which is the formation of extra fibrous tissue in the area behind the stomach and intestine
  • Have lymph node enlargement (lymphadenopathy), low thyroid (hypothyroidism) or kidney disease

People with type 2 autoimmune pancreatitis:

  • Are often over age 40 (one or two decades younger than those with type 1)
  • Are as likely to be female as male
  • Have a 30 percent chance of having inflammatory bowel disease, such as ulcerative colitis

When to see a doctor

Autoimmune pancreatitis often doesn't cause any symptoms. See your doctor, however, if you experience unexplained weight loss, abdominal pain, jaundice, or other signs and symptoms that bother you.

Dec. 20, 2014