Baseline and contrast-enhanced ultrasound features of hepatic epithelioid angiomyolipoma

BACKGROUND: Recurrence or metastasis after surgery had been reported in hepatic epithelioid angiomylipoma (epi-AML). Most hepatic epi-AMLs were misdiagnosed with hepatocellular carcinoma or other hepatic tumors before surgery. OBJECTIVE: To describe the baseline and contrast-enhanced ultrasound (CEUS) features of hepatic epi-AMLs and to explore the potential ultrasonic features for prognosis. METHODS: The retrospective study enrolled 67 patients (56 females, 11 males) with 67 pathologically confirmed hepatic epi-AML lesions. All the lesions were examined by baseline ultrasound and 42 lesions were examined using CEUS with SonoVue (Bracco, Milan, Italy) before surgery. RESULTS: Baseline ultrasound features of hepatic epi-AMLs included heterogeneous echo (86.6%), well-defined border (68.7%), hypoecho (64.2%), regular morphology (62.7%), peripheral-tumor arc-shaped or ring-like vessels (53.7%), and low value of resistive index (0.51 +/- 0.08). CEUS features of hepatic epi-AMLs included arterial phase hyper-enhancement with smooth and well-defined margin (100%), peripheral-tumor ring-like vessels (57.1%), and intra-tumor vessels (52.4%). Some CEUS features, including arterial phase heterogeneously tortuous filling, intra-tumor vessels and peripheral-tumor ring-like vessels were more commonly found in hepatic epi-AMLs of uncertain malignant potential/malignant than in benign hepatic epi-AMLs (p < 0.05). CONCLUSIONS: Baseline ultrasound and CEUS features may be useful in diagnosis of hepatic epi-AML, and some CEUS features may be indicative of its malignant potential.