title: Idiopathic duct-centric pancreatitis: disease description and endoscopic ultrasonography-guided trucut biopsy diagnosis.
abstract: OBJECTIVE
  Recent data demonstrate the presence of two autoimmune pancreatitis (AIP) subtypes. All existing endoscopic ultrasonography-guided trucut biopsy (EUS-TCB) data pertain to type 1 disease. Our aim is to determine if EUS-TCB samples are sufficient for diagnosing type 2 AIP.
  
  
  METHODS
  This is a retrospective case series conducted in an academic tertiary care center. Patients included those with type 2 AIP (n = 5), retrospectively identified from a database of all patients with AIP, diagnosed by HISORt criteria (n = 125). The primary outcome measure was the diagnostic capability of EUS-TCB for type 2 AIP.
  
  
  RESULTS
  5 patients (4 male, 1 female; mean age 39.6 years) who underwent EUS-TCB were diagnosed with type 2 AIP. The serum IgG(4) level was elevated in 1 of the 4 patients tested. CT/MRI revealed diffuse pancreas enlargement (n = 3), a pancreas head mass (n = 1), and a normal pancreas (n = 1). Prior to EUS, AIP was not specifically suspected, but part of a broad differential (n = 3) or not suspected at all (n = 2). Fine-needle aspiration was negative for neoplasia and AIP. The TCB histology was definitive (n = 4) or suggestive (n = 1) for type 2 AIP. No complications developed.
  
  
  CONCLUSIONS
  EUS-TCB may be safe and may provide sufficient material to definitively diagnose type 2 AIP. and IAP.
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905, USA. levy.michael@mayo.edu
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Levy
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Smyrk
authors.forename: Naoki
authors.initials: N
authors.lastname: Takahashi
authors.forename: Lizhi
authors.initials: L
authors.lastname: Zhang
authors.forename: Suresh T
authors.initials: ST
authors.lastname: Chari
mesh_terms: D000328:Adult; D000368:Aged; D001327:Autoimmune Diseases / Q000150:complications / Q000175:diagnosis*; D001707:Biopsy, Needle; D019160:Endosonography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010183:Pancreatic Ducts / Q000473:pathology*; D010195:Pancreatitis / Q000150:complications / Q000175:diagnosis*; D012189:Retrospective Studies; D018084:Ultrasonography, Interventional