Magnetic resonance imaging of hepatocellular carcinoma: a spectrum of uncommon morphologic subtypes, unusual imaging patterns and mimics

Advances in imaging techniques have evolved, allowing for early noninvasive diagnosis and improved management of high-risk patients with hepatocellular carcinoma (HCC). The hallmark imaging features of HCC on multiphasic cross-sectional imaging can be explained by the multistep process of hepatocarcinogenesis and is seen in 60% of cases. However, approximately 40% of cases do not abide by the classic imaging appearance and may pose a diagnostic challenge for radiologists. These may be accounted by their morphologic subtypes with differing molecular and/or genetic features. Additionally, various malignant and benign lesions and pseudolesions may mimic HCC. This article aims to highlight the unusual cross-sectional imaging manifestations of HCC and describe its pitfalls and mimics.