409 patients with hepatic epithelioid angiomyolipoma: A pooled analysis

Objective To summarize our experience in the diagnosis and treatment of hepatic epithelioid angiomyolipoma (HEAML), with the aim to reduce the future misdiagnosis rate. Methods The PubMed, Medline, China Science Periodical Database (CSPD), and VIP Databases were searched from January 2000 to March 2018 on all reports on HEAML. Results There were 409 cases of HEAML in 97 reports. The ratio of men to women was 1:4.84. The age ranged from 12 to 80 years and the median age was 44 years. 61.9% of patients (205/331) were asymptomatic, while 34.7% (115/331) had upper or right upper quadrant abdominal discomfort. Some patients presented with abdominal mass, gastrointestinal reaction, low grade fever or weight loss. The clinical symptoms in 78 patients were not mentioned in the reports. The misdiagnostic rate of HEAML was as high as 40.3% (165/409). The imaging findings of HEAML were non-specific. Ultrasound, CT and MRI scan usually showed contrast enhancement in the arterial phase. Most lesions were accompanied by central vessels with early drainage veins. The enhanced scans showed varied characteristics. The ratios of fast wash-in and fast wash-out, to fast wash-in and slow wash-out, and to delayed enhancement were roughly 4:5:1. A definitive diagnosis of HEAML is based on the pathological findings of epithelioid cells in the lesions and the expressions of HMB45, SMA, Melan-A and Actin on immunohistochemical staining. HEAML had a relatively low malignant rate of 3.9%. Surgical resection was the main treatment for HEAML. Conclusion HEAML was a rare and easily misdiagnosed disease. ,which could be diagnosed by taking into account the clinical course, imaging, pathological and immunohistochemical findings.HEAML Key words: Hepatic epithelioid angiomyolipoma (HEAML); Imaging; Pathology; Immunohistochemistry; Misdiagnosis