Malignant potential of hepatic angiomyolipoma: case report and literature review.

Hepatic angiomyolipoma (AML) is known as a rare benign tumor with invasive growth. In the past, some of these tumors were misdiagnosed as hepatocellular carcinomas, because of the similar pattern on imaging studies. Recently, correct diagnoses have been increasing, with the development of HMB-45 immunohistochemical staining, and it appears that the majority of these tumors behave as benign tumors. However, there are not a few cases which have resulted in fatal courses because of recurrence and metastasis of the tumor. The clinical features and signs of the malignant potential of this tumor are unknown; thus, the management and treatment of the tumor are still controversial. Here in this article, we report a case of hepatic AML which showed a size increase of 175% in 1 year, and portal vein thrombosis detected by angiography. During a follow up of 3 years after a curative hepatic lobectomy, no metastasis or recurrence was seen. Review of the literature suggests that portal vein thrombosis could be one of the markers of the malignant potential and transformation of this tumor. Therefore, in this paper, we recommend surgical treatment of hepatic AML in which there is a strong suspicion of portal vein thrombosis.