Autoimmune pancreatitis (AIP) is a relatively rare disorder of the pancreas. Although initially described in elderly male patients, recently reported case series have shown the disorder to be quite heterogeneous. There appears to be an increased incidence in some regions around the world, particularly in Japan. It remains to be seen whether this represents merely an increased clinical awareness or due to an actual increased prevalence of the disease.
Autoimmune pancreatitis (AIP) can be particularly challenging to diagnose because the way it presents itself closely resembles pancreatic cancer. The most common sign, present in about 80 percent of people, is painless jaundice, caused by blocked bile ducts. AIP can also cause weight loss. Masses in the pancreas and other organs of many people with autoimmune pancreatitis can be misdiagnosed as cancer.
Although diagnosis of autoimmune pancreatitis is challenging to make, accurate and timely diagnosis may preempt the misdiagnosis of cancer and decrease the number of unnecessary pancreatic resections.
Autoimmune pancreatitis responds dramatically to corticosteroid treatment and often is completely resolved with steroid treatment.