Angiomyolipoma of the liver: case report

Hepatic angiomyolipoma is a rare benign mesenchymal tumor of the liver. Most multiple hepatic angiomyolipomas have appeared in patients with renal angiomyolipoma and tuberous sclerosis. A 38-year-old female patient without chronic hepatitis B or C was hospitalized because of epigastric fullness for 2 months. Radiologic studies showed a large solid tumor with a small daughter nodule in the right hepatic lobe. Upon intravenous bolus injection of contrast medium, both tumors showed weak heterogeneous enhancement in the delayed phase. Although hepatocellular carcinoma was suspected by the findings of computed tomography, percutaneous transhepatic ultrasound-guided biopsy was performed for the large tumor. The histopathology showed many mature fat cells intermingled with thick-walled blood vessels, and epithelioid cells with eosinophilic cytoplasm; the epithelioid cells stained positively for HMB-45 and smooth muscle actin. Angiomyolipoma of the liver was confirmed. The main tumor enlarged considerably during a follow-up period of 3 years. Surgical resection was performed due to persistent symptoms. She had an uneventful postoperative recovery and was well when followed up 10 months after surgery. We should be aware that a hepatic angiomyolipoma can change in size during its natural course, and this finding does not necessarily indicate malignancy.