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.