Inflammatory pseudotumor of the liver: case report and review of literature.

Inflammatory pseudotumor (IPT) is a benign tumorous lesion of unknown cause, which is composed of fibrous tissue with infiltration of plasma cells and lymphocytes. A 57-year-old male with gastritis was indicated to have hepatic dysfunction during observation of the course of gastritis at a nearby hospital. He was referred to our facility to undergo detailed examinations. When he visited our hospital for the initial examination, he had no subjective symptoms. His past medical history was unremarkable. There were no distinct abnormalities on the medical examination. Blood tests revealed a white blood cell count of 10400 / L, CRP of 0.29 mg/dl, AST of 31 IU/L, ALT of 46 IU/L, ALP of 583 IU/L and -GTP of 408 IU/L, showing a mild inflammatory reaction and elevated hepatobiliary enzymes. Abdominal ultrasonographic examination revealed a tumor mass approximately 4 cm in diameter in a lateral hepatic segment. The margin and center of the mass were hypoechoic and iso- to hyperechoic, respectively, and the inside of the mass was non-homogeneous. Needle biopsy revealed only inflammatory findings with no indications of malignancy. Since computed tomography (CT) of the abdomen, done 4 months after detection of the tumor mass, revealed the mass to have increased to approximately 6 cm in diameter, excision biopsy was considered. The CT taken 2 months later revealed the mass to have regressed to approximately 2 cm in diameter, but excision of the lateral hepatic segment was undertaken at the patient's request. As a result, the diagnosis of IPT of the liver was confirmed. Imaging findings of hepatic IPT are variable and specific findings are lacking. Since the rate of correct diagnosis with needle biopsy is also low, IPT of the liver is often very difficult to differentiate from malignant tumors. On the other hand, since it may show spontaneous regression, indications for surgery must be assessed very carefully.