Inflammatory pseudotumor of liver--a clinical review of 15 cases

BACKGROUND/AIMS: Inflammatory pseudotumor rarely occurs in the liver. However, it is important to discriminate it from malignant hepatic tumor in order to avoid unnecessary surgery. We aimed to elucidate the characteristic features of this disease entity by analyzing our experiences and by reviewing the related literatures. METHODS: Fifteen patients were enrolled during a recent three-year period. The patients were pathologically diagnosed with inflammatory pseudotumor of the liver, and their clinical and imaging findings were analyzed retrospectively. RESULTS: Our study population was composed of ten men and five women, and their mean age was 60.3+/-9.2 years. Their initial diagnoses were inflammatory pseudotumor (n=8), malignant tumors (n=3) and abscess (n=4). Twelve of 15 patients were associated with biliary diseases such as biliary stone, gallbladder cancer, empyema or cholangiocarcinoma. The most common symptom was abdominal pain. The most common CT and MR findings could be summarized as a delayed hyperattenuating mass with an internal hypoattenuating component. The tumors were solitary in 13 patients and multiple in two patients. The lesions regressed spontaneously in seven patients. Four patients were treated by antibiotics and 3 patients by surgical resection. CONCLUSIONS: Inflammatory pseudotumor of the liver seems to have relatively common clinical and imaging features, as described above. However, these features are not disease-specific; thus, preoperative histologic confirmation is necessary to avoid unnecessary surgery.