Keywords:
Abdomen, Pancreas, MR, Contrast agent-intravenous, Pathology, Neoplasia
Authors:
F. Castelli, R. Negrelli, L. Zantedeschi, A. Ventriglia, R. Manfredi, R. Pozzi Mucelli; Verona/IT
DOI:
10.1594/ecr2012/C-1200
Purpose
Autoimmune pancreatitis is a distinct form of chronic pancreatitis,
characterized clinically by frequent presentation with obstructive jaundice with or without a pancreatic mass,
histologically by a lymphoplasmacytic infiltrate and fibrosis and therapeutically by a dramatic response to steroids [1].
Although the pathogenesis of AIP remains unclear,
an immune-mediated mechanism has been postulated.
This disease typically affects males without a history of alcohol abuse,
biliary stone disease,
or duodenal wall inflammation.
This is supported by the remission of the signs and symptoms related to pancreatic inflammation and the resolution of diagnostic imaging changes after short-term steroid treatment [2-5].
Morphologically AIP has been divided into diffuse and focal form; the first one affects elderly patients and may be misdiagnosed as acute,
chronic pancreatitis and lymphoma whereas the focal form is more often associated with obstructive jaundice,
abdominal pain,
weight loss and must be differentially diagnosed from pancreatic cancer.
[6-11] At magnetic resonance,
pancreatic imaging findings shows a diffuse or focally enlarged pancreas with hypointense signal of the lesion on T1-weighted images,
hyperintense on T2-weighted images and delayed contrast enhancement.
[12-18]
The aim of this study was to evaluate the MRI-MRCP findings of focal form of AIP and to describe ductal system involvement at diagnosis and at follow-up.