Focal autoimmune pancreatitis versus pancreatic cancer: value of steroid treatment in the diagnosis

Background: The differential diagnosis of pancreatic cancer and focal forms of autoimmune pancreatitis is complicated since serological tests, IgG4 and CA 19-9 have a low sensibility and specificity. CT scan and magnetic resonance imaging provide clear differentiation in the majority, but not in all cases. Endosonography is the most precise diagnostic procedure and allows to obtain samples for cytology or even histological studies. Aim: To report the experience with 18 cases of focal autoimmune pancreatitis and three cases of pancreatic cancer. Material and Methods: Review of medical records of 18 patients with focal autoimmune pancreatitis and 3 cases of pancreatic cancer. Results: The eighteen patients with focal autoimmune pancreatitis were treated with prednisone 0.5 mg/kg/day obtaining a complete clinical and morphological recovery in all. However, 3 had a relapse and one was operated. During follow up, none has developed a pancreatic cancer. The 3 patients with pancreatic cancer did not respond to steroidal treatment. Conclusions: The quick and dramatic response to steroids of autoimmune pancreatitis, may be useful and is recommended for the differential diagnosis with pancreatic cancer.