Inflammatory pseudotumor of the liver and peripheral eosinophilia in autoimmune pancreatitis

Abstract

Aim: Inflammatory pseudotumor (IPT) of the liver is a rare benign lesion, the etiology of which remains obscure. It is not associated with any particular diseases apart from phlebitis and Crohn's disease.

Methods: A middle-aged male with hepatic IPT and peripheral eosinophilia associated with autoimmune pancreatitis (AIP) was selected for this study and review of literature.

Results: A 59-year-old male was admitted with obstructive jaundice, marked eosinophilia (1 343/mm(3)) and hypergammaglobulinemia (4 145 mg/dL). Imaging techniques revealed dilatation of the intrahepatic bile duct, stenosis of the common bile duct with diffuse wall thickening, gallbladder wall thickening, irregular narrowing of the pancreatic duct, and swelling of the pancreatic parenchyma. Multiple liver masses were also demonstrated and diagnosed as IPT by biopsy specimens. Six months later, the abnormal features of the biliary tree remarkably improved by the oral administration of prednisolone, and the liver masses disappeared. The swelling of the pancreatic head also improved. The peripheral eosinophil count normalized. IPT associated with AIP, as we know, has not been reported in the literature. The clinical features of the present case mimicked those of pancreatic cancer with liver metastasis. This case deserves to be documented to prevent misdiagnosis of similar cases.

Figure 1

A: CT demonstrated dilatation of the intrahepatic bile ducts, swelling of the pancreatic head, thickening of the gallbladder wall; B: CT revealed the liver mass, which was not enhanced by contrast medium.

Figure 2

Ultrasonography demonstrated hypoechoic liver mass.

Figure 3

MRCP showed stricture of the common bile duct with marked dilatation of the intrahepatic bile duct and irregular narrowing of the pancreatic duct.

Figure 4

Biopsy specimens from the liver mass showed lymphocytes, histiocytes, plasma cells, and a number of eosinophils. It did not contain normal liver tissue or malignant cells.

Figure 5

CT revealed that the pancreatic swelling almost resolved 1 mo after the treatment. Liver masses decreased.

Figure 6

MRCP demonstrated the normalized bile duct 6 mo after the treatment.