Inflammatory pseudotumor of the liver with primary sclerosing cholangitis

Inflammatory pseudotumor (IPT) of the liver is a rare benign variant of hep atic masses, and its exact etiology has not been elucidated. We report a ca se of IPT associated with primary sclerosing cholangitis (PSC). The patient was a 50-year-old man admitted to our hospital because of jaundice. Abdomi nal ultrasonography (US) and computed tomography showed multiple dilations of the intrahepatic bile ducts and multiple masses in the liver. On magneti c resonance imaging, the masses were slightly hypointense on T1-weighted im ages and slightly hyperintense on T2-weighted images. On T1-weighted images after the bolus infusion of Gd chelate. the masses had no contrast enhance ment, and they were hypointense in the arterial phase and portal venous pha se. However. they were slightly enhanced and became almost isointense relat ive to the surrounding normal liver parenchyma in the delayed phase. Endosc opic retrograde cholangiography demonstrated multiple irregular strictures and dilations of the intrahepatic bile ducts. Angiography demonstrated no a bnormal findings, but, interestingly, subsequent dynamic CO2-enhanced US sh owed a strongly hyperechoic string, indicating that an artery had penetrate d through the hypoechoic mass. A US-guided percutaneous needle biopsy revea led that the lesions were morphologically comparable to IPT. After cholangi ography and microscopic analysis of the tumor, the final diagnosis was dete rmined to be IPT of the liver with PSC. A number of previous reports have s uggested a possible relationship between IPT and PSC, based on pathological findings. This report confirmed, based on clinical findings, that PSC is o ne of the causes of hepatic IPT.