['It is accepted that inflammation promotes malignant progression in the development of cancers. Whether, this is true for hepatocellular carcinoma (HCC) remains as an open question. We examined the relationship between the inflammatory histology activity index (HAI) in the background liver cirrhosis (LC) and the histological grading of the HCC in the hepatectomized HCC patients with HCV-associated LC.', "Out of 264 HCC patients who underwent curative hepatic resection, 197 had HCV-associated LC. Among them, 52 patients with a small solitary HCC nodule (< 5 cm in diameter) were studied. Inflammation in the background LC was evaluated by modified Knodell's HAI. To evaluate the inflammation, piece meal necrosis, intra lobular cellular degeneration and focal necrosis, portal cellular inflammation (0-4, each) were estimated. The average HAI was calculated. The grade of malignancy of HCC was determined by WHO classification.", 'The average HAI in the 15 patients with moderately differentiated HCC (4.3 ± 0.8, mean ± SD) was significantly larger than that in 11 patients with well differentiated HCC (3.5 ± 0.6, p = 0.036). The HAI in the 24 patients whose HCC nodules contained poorly differentiated HCC (5.2 ± 1.1) was significantly larger than that in patients with moderately differentiated HCC (p = 0.025). Thus, the HAI order was well differentiated group < moderately differentiated group < poorly differentiated group.'] Does inflammation in background cirrhosis evoke malignant progression in HCC development from HCV-associated liver cirrhosis?