Imaging findings of haemorrhagic hepatic cysts with enhancing mural nodules: Comparison with mucinous cystic neoplasms

Haemorrhagic hepatic cysts (HHCs) with enhancing mural nodules are an uncommon entity which can have overlapping imaging findings with hepatic mucinous cystic neoplasms (MCNs), leading to misdiagnosis. We aim to find differentiating imaging features between the two entities in this study. Patients with histologically proven HHCs and hepatic MCNs between January 2011 and January 2022 were identified from the Singapore General Hospital Department of Pathology database. Those with pre-operative computed tomography (CT) or magnetic resonance imaging (MRI) studies were included in our study. A total of ten patients met the inclusion criteria. Six had histologically proven HHCs and four had hepatic MCNs. Most of the patients with HHCs were female (83 %) while all patients with hepatic MCNs were female. Most of the HHCs were associated with three or more cysts (67 %), while the hepatic MCNs were either solitary or associated with fewer cysts. Most of the mural nodules of HHCs demonstrated progressive enhancement, T2-w hypointense rim with hyperintense centre. None of the hepatic MCNs contained mural nodules. HHCs were mostly unilocular without septa. Only one HHC had septa which arose from the cyst wall without indentation (17 %). All hepatic MCNs had septa that mostly arose from the cyst wall without indentation (75 %). HHCs with enhancing mural nodules are a recognised entity with some imaging features that help to distinguish them from hepatic MCNs. HHCs are typically unilocular whilst the presence of septa and septa arising from the cyst wall without external indentation favour hepatic MCNs.