Angiomyolipoma with vascular invasion during pregnancy.

Angiomyolipoma (AML) is a rare, benign tumor composed of fat cells, smooth muscle cells, and blood vessels. They are commonly found in the kidney but have also been reported to occur in the liver, ovary, fallopian tube, spermatic cord, palate, and colon. Most often, they are discovered as an incidental finding on computed tomography scan and remain inconsequential; however, certain characteristics such as size, presence of aneurysms, and location can transform this disease process into a life-threatening entity. Here, we describe the case of a 30-year-old pregnant woman with bilateral renal AMLs in which there was invasion of the right renal vein and extension of the tumor into the inferior vena cava. The patient was believed to be at significant risk of hormone-mediated rapid expansion, embolization, and life-threatening pulmonary embolus during the pregnancy and was taken to the operating room for right nephrectomy and removal of the tumor from the vena cava. We report the first case of elective nephrectomy with the removal of the tumor from vena cava complicating pregnancy. The major risks of rupture, spontaneous hemorrhage, renal failure, and tumor thrombus were avoided, thereby demonstrating that despite pregnancy, successful surgery can be performed during the second trimester for the management of complicated AMLs.