Microvessel density of malignant and benign hepatic lesions and MRI evaluation

AIM: To study the difference of microvessel density (MVD) between malignant and benign hepatic lesions and study the relationship between MVD and dynamic enhanced magnetic resonance imaging (MRI) for evaluation of microvessels within malignant and benign hepatic lesions. METHODS: A total of 265 specimens of hepatocellular carcinoma (HCC), 122 cirrhosis tissues and 22 hepatic benign lesions were enrolled for MVD by immunohistochemistry on tissue microarray, of which 49 underwent MRI examination before surgery, then contrast-to-noise ratios (CNR) and enhancement index (EI) in all the phases were calculated. Pearson correlation was performed for correlation analysis between CNR, EI and MVD. RESULTS: MVD of HCC was 22.7 +/- 15.8 (mean +/- SD), which was obviously higher than that of cirrhosis tissue (8.3 +/- 7.6, P<0.01), but was not statistically different from that of benign lesions (31.3 +/- 22.7, P>0.05). Among HCC, MVD of gradesIII was 29.9 +/- 18.6, which was much higher than those of grade III (22.2 +/- 18.2, P<0.01) and gradeIV (22.9 +/- 19.0, P<0.01). MVD of HCC (P=0.018) and of benign lesions (P=0.014) were both correlative with CNR in arterial phase. CONCLUSION: Neoangiogenesis is an important feature for malignant tumor, and MVD may act as a biological marker in differentiating malignant from benign hepatic lesions. Dynamic enhanced MRI, especially image in arterial phase, may act as an MVD evaluation criterion for malignant and benign hepatic lesions.