Inflammatory pseudotumor of the liver in a patient with chronic hepatitis C: Difficulty in differentiating it from hepatocellular carcinoma

A case of an inflammatory pseudotumor of the liver in a 75-year-old female with chronic hepatitis C whose radiologic features simulated that of hepato cellular carcinoma (HCC) is presented. On imaging studies, hypervascularity by CO2 ultrasound (US) angiography, enhancement at an early phase and isod ensity at a late phase by incremental dynamic computed tomography (CT), per fusion defect by CT during arteriography (CTAP), and clinical background of hepatitis C virus (HCV) infection strongly suggested HCC. A US-guided need le biopsy revealed a mainly diffuse and polyclonal proliferation of lymphoc ytes positive for leukocyte common antigen (pan-lymphocyte cells), L-26 (B cell lymphocytes), and UCHL-1 (T cell lymphocytes), negative for both x and lambda light chains and sparsely distributed neutrophils and histiocytes. No lymphoid follicles were observed. The liver tissue around this tumor sho wed chronic hepatitis with mild activity and mild fibrosis. These histopath ologic findings suggested that the diagnosis of inflammatory pseudotumor of the liver was tenable. As it is difficult to differentiate between inflamm atory pseudotumor of the liver and HCC by imaging studies alone, supplement al biopsy, where possible, should be obtained when diagnostic imaging of tu mors suggesting HCC is carried out. We emphasize that histopathology is a t rue gold standard in the diagnosis of this disease.