Duct-narrowing chronic pancreatitis without immunoserologic abnormality: comparison with duct-narrowing chronic pancreatitis with positive serological evidence and its clinical management

We reviewed the clinical features and clinical course of patients with duct-narrowing chronic pancreatitis who were negative for immunoserologic test results (n = 16) in comparison with the findings for serological test-positive patients (n = 20) in order to determine an adequate treatment for those who had typical morphology of autoimmune pancreatitis in the absence of immunoserologic abnormality. No significant differences were found between the two groups of patients in clinical profiles including associated autoimmune-related diseases, pancreatic histology, and response to steroid therapy. Of the seronegative patients, eight who showed an improvement in narrowing of the main pancreatic duct with steroid therapy and three who did no show an improvement or who relapsed after surgical resection without this therapy had stenosis of the common bile duct with increased levels of serum hepatobiliary enzymes, except for two patients with affected sites limited to the body or tail of the gland. For the remaining five patients, who showed an improvement in pancreatic duct changes or long-term remission after surgery without steroid administration, normal biochemistry test results for liver functions were obtained, with no abnormal cholangiographic findings in the three patients examined. Duct-narrowing chronic pancreatitis without immunoserologic abnormality overlaps in clinical features with that fulfilling the immunoserologic criteria for a diagnosis of autoimmune pancreatitis. In particular, the disease with bile duct involvement should be treated clinically as autoimmune pancreatitis, for which steroid therapy is recommended, even if an autoimmune mechanism is not demonstrated serologically.

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

INTRODUCTION

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.

AIM AND METHODOLOGY

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.

CONCLUSION

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.