Fig. 9

A 42-year-old female with incidental detection of liver nodule. (a) Axial T2W MRI shows a small ill-defined lesion in segment 6 with vague T2 hyperintense areas. Axial T1 in-phase (b) and out-of-phase (c) MRIs show a drop in signal around the lesion indicating perilesional steatosis. Axial post-contrast MRI shows moderate enhancement (arrows) in the arterial phase (d) becoming iso- to mildly hypointense on delayed phase (e). Ultrasound-guided biopsy revealed hepatocellular adenoma (immunohistochemistry and genetic analysis not performed). Follow-up MRI after 2 years showed significant interval growth (short arrow) with vague T2 hyperintense areas (long arrow) on axial T2W MRI (f). Axial post-contrast MRI shows moderate heterogeneous enhancement (arrow) in the arterial phase (g) becoming iso- to mildly hypointense on delayed phase (e) with mild delayed enhancement of a vague central scar (long arrow). Surgical resection showed hepatocellular adenoma with multiple foci of well-differentiated hepatocellular carcinoma and genetic analysis revealed β-catenin mutation