Hepatic epithelioid angiomyolipoma mimicking hepatocellular carcinoma on MR and 18F-FDG PET/CT imaging: A case report and literature review

Abstract

Hepatic epithelioid angiomyolipoma (HEAML) is a rare hepatic mesenchymal tumor with malignant potential. Unlike hepatic angiomyolipoma, HEAML is devoid of adipocytes. Thus, it is easy to be misdiagnosed as other tumors of liver, especially hepatocellular carcinoma (HCC) on preoperative imaging examinations. Herein, we present a case of HEAML mimicking HCC on magnetic resonance (MR) and fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in a 50-year-old female. After the primary diagnosis of HCC, the patient underwent a laparoscopic resection. The histopathology and immunohistochemical staining helped to reach the final diagnosis of HEAML. The important sign of central vessel can be seen on MRI in this case. The average apparent diffusion coefficient (ADC) value of the HEAML is 0.86±0.13x10^-3mm²/s, which is lower than that of 0.97±0.02?10^-3mm²/s of the normal liver. Previous literature on ¹⁸F-FDG PET/CT imaging of HEAML is limited to only 2 cases. The ¹⁸F-FDG PET/CT images of HEAML with high ¹⁸F-FDG accumulation with a maximum standardized uptake value (SUVmax) of 8.88 and extensive necrosis are presented, indicating its malignant potential. This case aims to improve the ability of differential diagnosis from HCC on multimodal imaging, and provides values for further ¹⁸F-FDG PET/CT related studies.