Focal Autoimmune Pancreatitis: A Simple Flow Chart for a Challenging Diagnosis

Abstract

Autoimmune pancreatitis is a chronic fibroinflammatory autoimmune mediated disease of the pancreas. Clinically, obstructive painless jaundice and upper abdominal pain are the main symptoms. Focal AIP is characterized by segmental involvement of pancreatic parenchyma and it is often radiologically represented by a pancreatic mass. In these cases, the diagnosis can be very challenging, since it may be easily confused with pancreatic cancer. Therefore, we suggest a combined approach of imaging tests as the diagnostic workup. EUS study combined with CEUS and elastography, if available, increases the accuracy of the method to rule out cancer. Moreover, the lesion should always be sampled under EUS guidance to obtain a cyto/histological diagnosis. The diagnostic workup should also include the use of diagnostic clinical criteria (extrapancreatic lesions, steroid response) and laboratory findings (CA 19.9 and IgG4 evaluations).

Applications of endoscopic ultrasound elastography in pancreatic diseases: From literature to real life

“…Of note, elastography may help the clinician to differentiate AIP from PC. Indeed, the former usually shows a homogeneous increase of stiffness in the whole organ, while in the latter the increased stiffness is limited within the tumoral area[ 19 ]. When using qualitative elastography in AIP, the inflamed area should have a predominantly green pattern with slight red or yellow lines, while a homogeneous green pattern should appear in the normal parenchyma[ 11 ].…”

“…Therefore, elastography does not represent the main tool to diagnose AIP, and even though helpful, it is not a crucial test in the differential diagnosis between PC and focal AIP. However, its simple application coupled with serial imaging examinations and fine needle biopsies could help clinicians reach a correct diagnosis[ 19 ].…”