A microscopic focus may be too small to be clinically evident if it become inflamed.
Ectopic pancreas can occur in several sites (including teratomas). Common sites are:
(1) gastric wall
(2) small bowel
(3) mesentery
Features of pancreatitis arising in an ectopic focus:
(1) abdominal pain, which may be recurrent
(2) elevated serum markers (amylase, lipase)
(3) normal pancreas on imaging studies
(4) variable dysfunction at site of ectopic tissue (paralytic ileus, gastric outlet obstruction, etc)
The ectopic focus can often be located on imaging studies (CT, MR cholangiopancreatography).
The diagnosis is confirmed if an ectopic site can be located and pancreatic tissue identified in the resected specimen.
