Regression of multiple hepatocellular adenomas after cessation of oral contraceptive pills : a case report and review of the current literature

Hepatocellular adenoma (HCA) is an uncommon benign liver neoplasm usually solitary and identified incidentally on imaging. We report a case of a 50-year old female who was diagnosed with multiple hepatic adenomas of the inflammatory subtype. After discontinuation of oral contraception a decrease of both the number and size of the liver lesions was seen on magnetic resonance imaging (MRI) without the need of further intervention. The major challenge in the clinical management of patients with multiple HCAs resides in the risk assessment for future complications. In the case of multiple HCAs subtype seemed to be more relevant than the actual number of lesions. Because little is known about the natural evolution in patients with multiple HCAs, we performed a review of the current literature with focus on the different subtypes and their clinical relevance.

HBP-enhancing hepatocellular adenomas and how to discriminate them from FNH in Gd-EOB MRI

Background Recent studies provide evidence that hepatocellular adenomas (HCAs) frequently take up gadoxetic acid (Gd-EOB) during the hepatobiliary phase (HBP). The purpose of our study was to investigate how to differentiate between Gd-EOB-enhancing HCAs and focal nodular hyperplasias (FNHs). We therefore retrospectively included 40 HCAs classified as HBP Gd-EOB-enhancing lesions from a sample of 100 histopathologically proven HCAs in 65 patients. These enhancing HCAs were matched retrospectively with 28 FNH lesions (standard of reference: surgical resection). Two readers (experienced abdominal radiologists blinded to clinical data) reviewed the images evaluating morphologic features and subjectively scoring Gd-EOB uptake (25–50%, 50–75% and 75–100%) for each lesion. Quantitative lesion-to-liver enhancement was measured in arterial, portal venous (PV), transitional and HBP. Additionally, multivariate regression analyses were performed. Results Subjective scoring of intralesional Gd-EOB uptake showed the highest discriminatory accuracies (AUC: 0.848 (R#1); 0.920 (R#2)—p < 0.001) with significantly higher uptake scores assigned to FNHs (Cut-off: 75%-100%). Typical lobulation and presence of a central scar in FNH achieved an accuracy of 0.750 or higher in at least one reader (lobulation—AUC: 0.809 (R#1); 0.736 (R#2); central scar—AUC: 0.595 (R#1); 0.784 (R#2)). The multivariate regression emphasized the discriminatory power of the Gd-EOB scoring (p = 0.001/OR:22.15 (R#1) and p < 0.001/OR:99.12 (R#2). The lesion-to-liver ratio differed significantly between FNH and HCA in the PV phase and HBP (PV: 132.9 (FNH) and 110.2 (HCA), p = 0.048 and HBP: 110.3 (FNH) and 39.2 (HCA), p < 0.001)), while the difference was not significant in arterial and transitional contrast phases (p > 0.05). Conclusion Even in HBP-enhancing HCA, characterization of Gd-EOB uptake was found to provide the strongest discriminatory power in differentiating HCA from FNH. Furthermore, a lobulated appearance and a central scar are more frequently seen in FNH than in HCA.