Imaging surveillance outcomes of hepatocellular adenomas: systematic review and meta-analysis

Hepatocellular adenomas (HCA) are typically resected if > 5 cm after 6 months due to historical risks of bleeding and malignant transformation. Outcomes of contemporary patients managed with surveillance are not well defined. We performed a systematic review and meta-analysis of patients with HCAs monitored for ≥ 6 months to assess rates of size stability, bleeding, and malignant transformation.

PubMed, Web of Science, and Embase databases were searched up to August 2025 for all articles reporting HCA and follow-up. Risk of bias was assessed with modified Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool. Pooled proportions of outcomes were assessed with linear mixed model and logistic regression. Heterogeneity was assessed with the I² index.

Of 679 articles screened, 7 retrospective studies (2019-2023) with 699 patients across Europe and United States were included. Five were multicenter. Median follow-up ranged from 2 to 5.8 years. For size stability, four studies used Response Evaluation Criteria in Solid Tumors (RECIST); others used a 1 cm size threshold, regression to < 5 cm, or unspecified criteria. Six studies showed moderate to serious risk of bias. Pooled proportion of HCAs that were stable or regressed was 88.5%. Pooled incidences of symptomatic bleeding and malignant transformation were 0.5% and 0.8%, respectively.

In a contemporary series, the majority of untreated HCAs were stable or regressed during surveillance, with extremely low incidences (< 1%) of bleeding and malignant transformation. Extending surveillance intervals may safely offer patients more time to address modifiable risk factors.