Autoimmune pancreatitis associated with primary sclerosing cholangitis: MR imaging findings.

Autoimmune pancreatitis is a relatively rare type of chronic pancreatitis that may be associated with other autoimmune disorders. The imaging features of this entity may be misleading and suggest the presence of a malignant tumour. We present a case in which MR imaging allowed us to diagnose autoimmune pancreatitis associated with primary sclerosing cholangitis, which is another autoimmune-related disease. Typical MR characteristics of autoimmune pancreatitis include focal or diffuse enlargement of the pancreas, the absence of parenchymal atrophy and significant dilation proximal to the site of stenosis, the absence of peripancreatic spread, the clear demarcation of the lesion and the presence of a peripancreatic rim.