title: Clinical study of chronic pancreatitis with focal irregular narrowing of the main pancreatic duct and mass formation: comparison with chronic pancreatitis showing diffuse irregular narrowing of the main pancreatic duct.
abstract: BACKGROUND
  Main pancreatic duct (MPD)-narrowed chronic pancreatitis (CP) may be an autoimmune abnormality. It also has been called autoimmune pancreatitis and sclerosing pancreatitis. It is unclear whether cases with focal pancreatographic changes are part of the same clinical entity as cases with diffuse MPD changes.
  
  
  OBJECTIVE
  We reviewed seven cases of chronic pancreatitis (CP) with focal narrowing of the main pancreatic duct (MPD), evidenced by endoscopic retrograde cholangiopancreatography (ERCP), and swelling of one or two segments of the pancreas, evidenced by ultrasonography (US) /computed tomography (CT), and indicated the clinicopathologic features of focal-type MPD-narrowed CP.
  
  
  RESULTS
  The patient group comprised six men and one woman, and their age range was 28-75 years, with a mean of 63.7 years. Affected sites were in the head in two patients, the body in one patient, the tail in one patient, and the body and tail in three patients; ERP showed narrowing in six patients and obstruction in one. Stricture of the lower portion of the common bile duct (CBD) that caused obstructive jaundice was shown by ERC in two cases in which the pancreas head was affected. In all six patients, a dynamic study by CT or MRI homogeneously showed delayed enhancement of involved segments of the pancreas. Serum levels of pancreatic enzyme were elevated in five patients, but only one subject had pancreatitis-like epigastric pain. Serological evidence suggestive of autoimmune abnormality was detected in only three patients with hypergammaglobulinemia (> or =2.0 g/dL) or positive titers of antinuclear antibody (ANA; > or =80). Histological assessment was available for five patients, who characteristically had dense lymphocytic or plasmocytic infiltration with severe fibrosis that caused luminal narrowing. The clinical, serologic, and histologic findings as described above were comparable to those for 12 CP patients with diffuse narrowing of the MPD, diagnosed during the same period. Surgical resection was performed in 5 patients, in 2 of whom a similar inflammatory process recurred in the remnant head of the pancreas, whereas pancreatitis no longer developed in the other 3 patients. One patient was initially treated with steroids, with clinical remission, although there was neither hypergammaglobulinemia nor positive ANA.
  
  
  CONCLUSIONS
  These results indicate that CP with focal narrowing of the MPD is part of the same clinical spectrum as CP with diffuse narrowing of the MPD, and whether the distribution is diffuse or focal seems to be related to the stage or the extent of the disease. It is therefore important to recognize the possible existence of this focal variant to avoid unnecessary surgery.
authors.affiliation: Department of Gastroenterology, Saiseikai Kanazawa Hospital, Kanazawa, Japan.
authors.forename: Tokio
authors.initials: T
authors.lastname: Wakabayashi
authors.forename: Yukimitsu
authors.initials: Y
authors.lastname: Kawaura
authors.forename: Yoshitake
authors.initials: Y
authors.lastname: Satomura
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Fujii
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Motoo
authors.forename: Takashi
authors.initials: T
authors.lastname: Okai
authors.forename: Norio
authors.initials: N
authors.lastname: Sawabu
mesh_terms: D000328:Adult; D000368:Aged; D002760:Cholangiopancreatography, Endoscopic Retrograde; D002908:Chronic Disease; D003251:Constriction, Pathologic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010183:Pancreatic Ducts / Q000000981:diagnostic imaging / Q000473:pathology*; D010195:Pancreatitis / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography