Differentiation between hepatic angiomyolipoma and hepatocellular carcinoma in individuals who are not at-risk for hepatocellular carcinoma.

PURPOSE: To develop a practical methodfor differentiating hepatocellular carcinoma (HCC) from angiomyolipoma (AML) in individuals who are not at-risk for HCC.

METHOD: We retrospectively enrolled consecutive patients who underwent gadoxetic acid-enhanced liver magnetic resonance imaging (MRI) and pathological confirmation between January 2008 and April 2022. Patients who underwent prior treatment, those with multiple lesions, or those at-risk for HCC were excluded. The training cohort included patients with pathological confirmation between 2008 and 2019, whereas the validation cohort included the remaining cases. Independent reviews of the MRI were performed by two reviewers. Using the clinical and MRI findings, we developed AML-HCC score using Firth's logistic regression in the training cohort, and the diagnostic performance was validated in the validation cohort.

RESULTS: Of the 206 patients, 156 were assigned to the training cohort (25 and 131 patients with AML and HCC, respectively) and 50 were assigned to the validation cohort (4 and 46 patients with AML and HCC, respectively). The AML-HCC score was defined as the sum of female (score 1), early draining vein (score 2), T2 homogeneity (score 1), necrosis or severe ischaemia (score -2), and HBP hyperintensity to spleen (score -1). When the AML-HCC score was ≥1, the sensitivity and specificity were 80% and 95% for the training cohort and 100% and 80% for the validation cohort, respectively.

CONCLUSIONS: We developed and validated an AML-HCC score to differentiate between AML and HCC in individuals who are not at-risk for HCC, and our model demonstrated good diagnostic performance.