Autoimmune pancreatitis with hepatic inflammatory pseudotumor.

We report a case of autoimmune pancreatitis (AIP) with hepatic inflammatory pseudotumor (IP). The patient was clinically diagnosed as having multiple metastatic tumors originated from cholangiocellular carcinoma as well as autoimmune pancreatitis and underwent left lobectomy of the liver. Histological examination showed a diffuse or dense lymphoplasmacytic infiltration with obliterating phlebitis but an absence of neoplastic proliferation both in the liver tumor and in the biopsy specimen of the pancreas. Abundant IgG4-positive plasma cells were seen in the lesions. This is the first case report that shows a simultaneous occurrence of hepatic IP and AIP, suggesting that these lesions appeared on the background of the recently proposed entity of IgG4-related systemic disease.