Focal nodular hyperplasia-like lesions in patients with cavernous transformation of the portal vein: prevalence, MR findings and natural history

PURPOSE: To retrospectively investigate the prevalence, MR findings, natural history, and association with other hepatic lesions of focal nodular hyperplasia (FNH)-like lesions in a cohort of consecutive patients with cavernous transformation of the portal vein (CTPV).MATERIALS AND METHODS: This retrospective IRB-approved study comprised 58 patients (32 men, 26 women; average age, 50 years) with CTPV who underwent liver MR imaging between 2000 and 2008. MR images were assessed by two radiologists in consensus for the presence of (a) FNH-like lesions and other liver lesions, and (b) other imaging findings. Patients were assigned to a stable or progressive clinical course based on lesion characteristics at follow-up.RESULTS: Twelve of 58 patients (21%) had 38 FNH-like lesions (average size, 1.3 cm). Common findings of FNH-like lesions were isointensity on T2-weighted images (82%), intense and homogeneous enhancement during the arterial phase, and lack of washout during the hepatic venous and interstitial phases (100%). FNH-like lesions were found with other benign liver lesions (1 hemangioma, 1 adenoma) in two patients. Three (25%) patients with FNH-like lesions showed a progressive clinical course.CONCLUSION: FNH-like lesions are commonly detected in patients with CTPV. Most lesions demonstrate benign imaging findings and stable clinical course.