Pancreatic Pseudocysts and Parenchymal Necrosis in Patients With Autoimmune Pancreatitis: A Systematic Review.

OBJECTIVE: To investigate the prevalence and natural history of pancreatic pseudocysts (PCs) and parenchymal necrosis in autoimmune pancreatitis (AIP). METHOD: A search using PubMed, Embase, Scopus, and Cochrane was performed. Search terms were AIP, PC, acute fluid collection, and pancreatic necrosis. RESULTS: Fifteen studies with 17 patients were included. In 8 of 17 patients, PC was noted concurrently with the AIP diagnosis, whereas in the other half, PC appeared months or years after. In 10 of 17 cases, PC appeared as solitary. The location was variable. Pseudocysts were small (<3 cm) in 4 cases and large (>3 cm) in 13 cases. A normal pancreatic duct was observed in 6 of 17 cases, whereas 9 of 17 had pancreatic duct stenosis. Steroids were given to 4 of 4 small and 10 of 13 large PC. All small PC resolved with steroids, whereas only 4 of 10 large PC treated had some response. Most (9/13) of large PC underwent endoscopic or surgical procedures. None of the 17 cases developed necrosis. CONCLUSIONS: Pseudocysts in AIP are rare. Pancreatic pseudocyst can present in variable number, size, and location. Small PC resolved with steroids. Large PC had poor response to steroids requiring invasive interventions. Necrosis in AIP has not been reported.