[35-year old male with fever and round mass of the liver].

A 35 year old male suffered from fever till 39 degrees C and malaise since 6 months; infectious or neoplastic causes have been ruled out. Ultrasonography revealed a hypoechoic lesion of 75 mm diameter in the liver. The histologic examination of the needle biopsy showed an inflammatory process, and the final diagnosis was inflammatory pseudotumor. EBV specific LMP-1 protein was detected within the tumor immunohistochemically. A liver segment resection was performed, and the patient has been well and without fever since then for 18 months. Inflammatory pseudotumor is a rare but important differential diagnosis in cases of hypoechoic liver lesions associated by fever, if there is no abscess or malignancy. The diagnosis must be confirmed histologically, because imaging techniques cannot reliably classify the lesion.