An update on recent developments in rupture of renal angiomyolipoma

Abstract

Background: Renal angiomyolipoma (AML) is a common benign tumor of the kidney. The main complication of AML is retroperitoneal hemorrhage caused by AML rupture, which can be severe and life threatening. The risk of AML rupture used to be determined by tumor size. However, these criteria have been challenged by series of clinical studies and case reports, suggesting prediction AML rupture based on tumor size is not always reliable.

Methods: The authors searched PubMed using "angiomyolipoma," "AML," and "rupture" and reviewed relevant studies. The authors investigated the risk factors of AML rupture using the retrieved literature. The authors also summarized current modalities to evaluate and manage AML.

Results: It is established that risk of AML rupture is associated with lesion size. However, genetic abnormality, aneurysm formation, and pregnancy are also risk factors for tumor rupture. Thus, the prediction of AML rupture should be based on a more comprehensive risk assessment system. The management of renal AML and tumor rupture was also discussed in the present paper.

Conclusion: The risk of AML rupture is associated with but not exclusive to lesion size. Any decision to intervene AML must be based on multiple factors including risk, symptoms, and auxiliary findings.

Figure 1

Schematic explanation of AML rupture and its risk factors. Pregnancy and genetic abnormalities contribute to microaneurysm formation and enlarged tumor size, which play the central role in AML rupture. Besides, precipitating factors such as anticoagulation treatment trigger AML rupture. AML = angiomyolipoma.