Radiological aspects of giant hepatocellular adenoma of the left liver: A case report

BACKGROUND: Hepatocellular adenoma (HCA) is very rare and has a high misdiagnosis rate through clinical and imaging examinations. We report a case of giant HCA of the left liver in a young woman that was diagnosed by medical imaging and pathology. CASE SUMMARY: A 21-year-old woman was admitted to our department for a giant hepatic tumor measuring 22 cm × 20 cm × 10 cm that completely replaced the left hepatic lobe. Her laboratory data only suggested mildly elevated liver function parameters and C-reactive protein levels. A computed tomography (CT) scan showed mixed density in the tumor. Magnetic resonance imaging (MRI) of the tumor revealed a heterogeneous hypointensity on T1-weighed MR images and heterogeneous hyperintensity on T2-weighed MR images. On dynamic contrast CT and MRI scans, the tumor presented marked enhancement and the subcapsular feeding arteries were clearly visible in the arterial phase, with persistent enhancement in the portal and delayed phases. Moreover, the tumor capsule was especially prominent on T1-weighted MR images and showed marked enhancement in the delayed phase. Based on these imaging manifestations, the tumor was initially considered to be an HCA. Subsequently, the tumor was completely resected and pathologically diagnosed as an HCA. CONCLUSION: HCA is an extremely rare hepatic tumor. Preoperative misdiagnoses were common not only due to the absence of special clinical manifestations and laboratory examination findings, but also due to the clinicians’ lack of practical diagnostic experience and vigilance in identifying HCA on medical images. Our case highlights the importance of the combination of contrast-enhanced CT and MRI in the preoperative diagnosis of HCA.