Diagnosis of autoimmune pancreatitis using its five cardinal features: introducing the Mayo Clinic's HISORt criteria.

Autoimmune pancreatitis (AIP) is a recently defined form of chronic pancreatitis. While numerous case reports and small case series of AIP have been reported from Japan, there have been relatively few from the West. Based on a retrospective review of our experience with resected AIP and a review of the literature, we have identified five cardinal features of AIP in histology, imaging, serology, other organ involvement, and response to steroid therapy, which are summarized in the mnemonic HISORt. A combination of the HISORt criteria can be used to definitively diagnose a wide spectrum of manifestations of AIP.