Brief Articles
Copyright ©2009 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Sep 28, 2009; 15(36): 4576-4581
Published online Sep 28, 2009. doi: 10.3748/wjg.15.4576
Epithelioid angiomyolipoma of the liver: Cross-sectional imaging findings of 10 immunohistochemically-verified cases
Peng-Ju Xu, Yan Shan, Fu-Hua Yan, Yuan Ji, Ying Ding, Mei-Lin Zhou
Peng-Ju Xu, Yan Shan, Fu-Hua Yan, Ying Ding, Mei-Lin Zhou, Department of Radiology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai 200032, China
Yuan Ji, Department of Pathology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai 200032, China
Author contributions: Xu PJ and Shan Y contributed equally to this work; Xu PJ, Shan Y, Yan FH designed the research; Xu PJ, Shan Y, Ji Y, Ding Y, Zhou ML performed the research; Xu PJ, Shan Y, Yan FH analyzed the data; Xu PJ, Shan Y, Yan FH wrote the paper.
Correspondence to: Fu-Hua Yan, Professor, Department of Radiology Zhongshan Hospital Fudan University, 180 Fenglin Road, Shanghai 200032, China.
Telephone: +86-21-64041990-3682 Fax: +86-21-64439906
Received: July 1, 2009
Revised: August 18, 2009
Accepted: August 25, 2009
Published online: September 28, 2009

AIM: To retrospectively evaluate the computed tomography (CT)/magnetic resonance imaging (MRI) imaging features of epithelioid angiomyolipoma of the liver (Epi-HAML), with pathology as a reference.

METHODS: The CT/MRI findings (number, diameter, lobar location, and appearance of lesions) in a series of 10 patients with 12 pathologically proven epithelioid angiomyolipomas of the liver were retrospectively analyzed. The imaging features, including attenuation/signal intensity characteristics, presence of fat, hypervascular, outer rim, and vessels within lesion, were evaluated and compared with that of non-Epi-HAML in 11 patients (13 lesions). The Fisher exact test was used to compare difference in probability of imaging features between the two types.

RESULTS: For 21 patients, CT images of 15 patients and MR images of six patients were available. No patient underwent two examinations. For the 15 patients with a CT scan, all HAML lesions in the two groups (10 Epi-HAML and seven non-Epi-HAML) manifested as hypoattenuation. For the six patients with MRI, all lesions (two Epi-HAML and six non-Epi-HAML) were hypointense on T1WI (fat suppression) and hyperintense on T2WI. There were 10 non-Epi-HAML, but only two Epi-HAML lesions showed the presence of fat, which significantly different between the two types (P = 0.005). On the dynamic contrast enhancement (DCE) imaging, eight Epi-HAML, and 13 non-Epi lesions manifested as hypervascular. Punctate or curved vessels were displayed in 10 Epi-HAML as well as in nine non-Epi lesions and outer rim enhancement could be found with eight Epi-HAML as well as six non-Epi lesions.

CONCLUSION: Little or no presence of adipose tissue was found to be an imaging feature of Epi-HAML, compared with the non-Epi type. In addition, hypervascularity with opacification of central punctiform or filiform vessels on DCE would be a characteristic enhancement pattern for Epi-HAML.

Keywords: Epithelioid angiomyolipoma, Liver, Immunohistochemical staining, Magnetic resonance imaging, Computed X-ray tomography