Publication:

When benign turns aggressive: renal angiomyolipoma with renal vein invasion

Angiomyolipoma (AML) is the most common benign kidney tumor, made up of fat, smooth muscle, and abnormal blood vessels. It represents 0.3-3% of kidney tumors and is more common in women. AMLs are typically diagnosed via computed tomography (CT) or magnetic resonance imaging (MRI), with most being asymptomatic and requiring no treatment. However, larger or symptomatic AMLs can cause hematuria, flank pain, or bleeding, necessitating treatments like selective arterial embolization, partial nephrectomy, or active surveillance. Recent studies question the traditional 4 cm intervention threshold, suggesting that larger AMLs may be safely monitored based on individual risk factors. This case report discusses a 47-year-old woman with a 4.1×2.1 cm AML with renal vein invasion, treated successfully with laparoscopic nephrectomy. The findings highlight the need for personalized treatment strategies considering tumor characteristics and patient factors, and emphasize the importance of ongoing renal function monitoring.