Chronic inflammatory pseudotumor arising in the hepatobiliary-pancreatic system: progressive multisystemic organ involvement in four patients.

OBJECTIVE: Inflammatory pseudotumor is a benign process that can involve most organ systems. The purpose of this report was to evaluate the imaging features of multifocal chronic inflammatory pseudotumor in four patients who presented with clinical, radiographic, and biopsy evidence of pancreatic or biliary malignancy.
CONCLUSION: To our knowledge, this is the first report in the radiology literature describing the imaging features of progressive multifocal inflammatory pseudotumor originating from a primary pancreatic or biliary focus. Even on retrospective review, no distinguishing imaging features were identified that could discriminate benign from malignant disease. These findings emphasize the importance of histopathologic analysis in the diagnosis of malignancy, particularly in patients with previously diagnosed inflammatory pseudotumor.