Pancréatites inflammatoires

Inflammatory pancreatitis refers to those pancreatic lesions that can occur with some autoimmune diseases, with an eosinophilic infiltration, during infection by Human Immunodeficiency Virus, and following abdominal radiotherapy. Differences exist between their specific clinical, biological, radiological, and histological patterns and those of the calcifying chronic pancreatitis; such differences must be taken into account for ensuring adequate therapy. Most of the time, autoimmune pancreatitis appears as a hypo-echogenic mass, hypo-attenuated on CT scans, hypo-intense on T1 weighted images, hyper-intense on T2, with a late enhancement after injection. Ductal changes are irregular stenoses only causing moderate upstream dilatation. Diagnosis is based on histological examination, showing a periductal inflammatory infiltration, constituted, in particular, of T lymphocytes. Eosinophilic pancreatitis is a histo-pathologically diagnosed pseudo-tumoral mass occurring in an atopic context, with increased IgEs. Both pancreatitis need corticoid-based therapy. Patients with Acquired Immune Deficiency Syndrome may develop pancreatic damages, acute most of the time, but also chronic and with ductal modifications and a pancreatic fibrosis of unknown aetiology to date. Finally, abdominal radiotherapy may cause chronic pancreatitis, occurring several years following the irradiation.