Diagnostic features of chronic pancreatitis distal to benign and to malignant pancreatic duct obstruction.

Differentiation between diffuse chronic pancreatitis and pancreatitis distal to a malignant or benign stenosis has important prognostic and therapeutic implications. We examined the retrograde pancreatograms of 64 patients with histologically confirmed diagnosis of diffuse chronic pancreatitis, chronic pancreatitis distal to a benign tumor and chronic pancreatitis distal to a malignant tumor. The nature of the stenosis was often difficult to determine from the shape of the pancreatic duct only. By using discriminant analysis it was possible to determine an allocation rule based on 8 criteria mainly derived from changes in the pancreatic ductuli. This allocation rule allowed the correct diagnosis to be made in 24 out of 26 patients with diffuse chronic pancreatitis (92%), 19 out of 20 patients with pancreatitis distal to a benign tumor (95%) and all 18 patients (100%) with pancreatitis distal to a malignancy.