Hepatic inflammatory pseudotumor: case report, review of the literature, and a proposal for morphologic classification

Inflammatory pseudotumors (IPT) are uncommon mass lesions arising most typi cally in the lungs of young adults. These tumors are so named because of th e difficulty in distinguishing them preoperatively from malignant lesions. IPT are characterized histologically by localized fibrous proliferations wi th infiltration by mononuclear leukocytes, particularly plasma cells. Seven teen previous cases of IPT involving the liver and biliary tree have been r eported in children. In this location, IPT may lead to biliary obstruction, portal hypertension, cirrhosis and eventually hepatic failure. We describe the youngest patient ever reported with hepatic IPT (HIPT) and biliary obs truction, who was successfully managed with a left hepatic lobectomy and Ka sai portoenterostomy. Based on all previous cases of HIPT in both adults an d children (74 cases), we propose a morphologic classification of these les ions based on the presence of single versus multiple lesions, with individu alized management. Type I lesions are large, solitary lesions, often with c entral necrosis, giving a characteristic radiographic appearance. Type 2 le sions are multiple smaller, solid nodules indistinguishable from metastatic malignancy.