Refining imaging criteria for mucinous cystic neoplasm of the liver: simplified diagnostic approach.

objectivesTo propose a simplified diagnostic approach for mucinous cystic neoplasm (MCN) of the liver and compare its diagnostic performance with the European Association for the Study of the Liver (EASL) criteria.

methodsWe conducted a retrospective cohort study of 124 patients with pathologically confirmed lesions (13 MCNs, 111 hepatic cysts) who underwent CT/MRI between January 2016 and January 2023. Two major features (thick septation, nodularity) and five minor features (upstream biliary dilatation, thin septations, internal hemorrhage, perfusion change, < 3 coexistent hepatic cysts) of the EASL criteria were evaluated. For a septa-wall relationship, the angle of indentation was measured, and the optimal angle predicting MCN was determined by receiver operating characteristic curve analysis. Logistic regression identified features predicting MCN, and a modified criteria was developed. The sensitivity, specificity, and accuracy of both criteria were compared using McNemar's test.

resultsThe optimal indentation angle was 111°. Absence of indentation or indentation at an angle > 111° (odds ratio (OR), 100.4; 95% confidence interval (CI), 4.9-2076.0) and < 3 coexistent hepatic cysts (OR, 47.8; 95% CI, 1.5-1489.1) were independent features predicting MCN. Our modified criteria used a combination of them and demonstrated greater accuracy (98.4% vs. 92.7%; p = 0.035) than the EASL criteria (a combination of ≥ 1 major and ≥ 1 minor feature[s]), with comparable sensitivity (92.3% vs. 76.9%; p = 0.317) and specificity (99.1% vs. 94.6%; p = 0.059).

conclusionOur modified criteria using two imaging features may be a promising alternative to current EASL criteria to improve accuracy in diagnosing MCN. KEY POINTS: Question Radiological diagnosis of mucinous cystic neoplasm of the liver remains challenging due to the lack of specific imaging features, leading to suboptimal treatment decisions. Findings No external indentation or an indentation angle > 111° and fewer than 3 coexistent hepatic cysts are independent factors predicting mucinous cystic neoplasm of the liver. Clinical relevance The simplified approach using these two imaging features for diagnosing mucinous cystic neoplasm of the liver offers improved accuracy and reliability over the 2022 EASL criteria, potentially reducing misdiagnosis and unnecessary surgeries.