Natural history of postvascular‐phase iso‐enhanced lesions on the sonogram in chronic liver diseases

Background and Aim This study examined the natural history of postvascular‐phase iso‐enhanced lesions ( PIELs ) on contrast‐enhanced sonograms to determine the potential risk and predictive factors for developing hepatocellular carcinoma ( HCC ) in chronic liver diseases. Methods This prospective study included 87 PIELs on contrast‐enhanced sonograms (postvascular‐phase: 10 min post‐injection of perflubutane microbubbles) in 72 patients with chronic liver diseases (45 males and 27 females; age 65.0 ± 10.8y; PIEL diameter 12.5 ± 4.2 mm). The PIELs were followed up by ultrasound/contrast‐enhanced ultrasound, computed tomography, or magnetic resonance imaging at 3 to 6 months intervals. Results Twenty patients developed HCCs during the study period (median, 22.0 months). The cumulative risk of HCC occurrence was 7.9% at 1 year and 36.0% at 3 years. The presence of coexistent HCC (hazard ratio [ HR ], 4.975; 95% confidence interval [ CI ], 1.729–14.316; P  = 0.003) and alpha‐fetoprotein > 20 ng/mL ( HR , 4.104; 95% CI , 1.621–10.392; P  = 0.003) were significant factors for the risk of HCC occurrence. Fourteen of these lesions were diagnosed as HCCs that developed from iso‐enhanced lesions. Cumulative HCC occurrence rates from PIEL  > 14 mm was 23.5% at 1 year and 46.3% at 3 years. Cox regression analysis showed that PIEL  > 14 mm ( HR , 6.780; 95% CI , 2.060–22.32; P  = 0.002) and alpha‐fetoprotein > 20 ng/ mL ( HR , 4.892; 95% CI , 1.559–15.350; P  = 0.007) were statistically significant factors for HCC occurrence. Conclusions Patients with coexistent HCC , alpha‐fetoprotein > 20 ng/ mL , or PIEL  > 14 mm should be carefully monitored because of the high potential for HCC occurrence.