[An autopsy case of pulmonary embolism due to renal angiomyolipoma in an elderly woman]

Multiple renal angiomyolipomas with asymptomatic nontraumatic pulmonary fat embolus: A case report

Although retroperitoneal bleeding and massive hematuria are potential complications of angiomyolipoma (AML), the pulmonary embolism as a presenting symptom is extremely rare. It is important to be aware that benign AMLs can present with pulmonary fat embolism.

Preoperative inferior vena cava filter implantation to prevent pulmonary fat embolism in a patient showing renal angiomyolipoma extension into the renal vein: A case report and literature review

Renal angiomyolipoma without local invasion is usually considered benign entity, however, it may extend into the renal vein or the inferior vena cava. Renal angiomyolipoma with venous extension should be treated; however, surgical complications such as iatrogenic pulmonary fat embolism remain a serious concern. We present a case of a 66-year-old Japanese woman without tuberous sclerosis in whom a right-sided renal tumor was incidentally detected on ultrasonography during a health check-up. Further evaluation showed that the tumor extended into the renal vein, and she was successfully treated using preoperative inferior vena cava filter placement and radical nephrectomy. An inferior vena cava filter can prevent catastrophic pulmonary fat embolism during nephrectomy.

Pre-operative renal artery embolization and suprarenal IVC filter placement for prevention of fat embolization in renal angiomyolipoma with venous extension

Though generally considered benign, angiomyolipomas can invade through the renal vein into the inferior vena cava, putting patients at risk of catastrophic pulmonary fat embolization. Venous invasion is thus an indication for surgical resection but is thought to increase the risk of adverse operative outcomes including intraoperative hemorrhage and embolization of fat and/or tumor thrombus. We report a novel approach to mitigating these complications illustrated in the case of a 43-year-old woman with IVC-invasive renal AML who underwent successful radical nephrectomy after concurrent pre-operative renal artery embolization and placement of a retrievable suprarenal IVC filter.

A renal angiomyolipoma with extension to the renal vein and asymptomatic fat pulmonary embolus

Renal angiomyolipoma (AML) is a rare benign tumor that can extend into the renal vein, inferior vena cava and the right atrium. AML is a mesenchymal tumor composed of smooth muscle, fat and vascular elements. In rare instances, the tumor may release a fatty tissue to the pulmonary vasculature, which can lead to cardiopulmonary collapse and death. Only four cases of fat pulmonary embolism secondary to AML have been reported in the literature but our case was the first to present as asymptomatic. Our patient had left renal AML extending to the renal vein that was associated with fat pulmonary embolus. The patient underwent uncomplicated radical nephrectomy and was discharged home on no anticoagulation. Follow-up chest computed tomography showed no extension of the pulmonary embolism. Whether embolectomy or anticoagulation is necessary in asymptomatic pulmonary embolism secondary to renal AML is unclear. Although controversial, some surgeons prefer to place an inferior vena cava filter prior to radical nephrectomy to prevent dislodgement of new intraoperative emboli, which can lead to catastrophic outcome.

Nephron sparing surgery for renal angiomyolipoma with inferior vena cava thrombus in tuberous sclerosis

Introduction. Angiomyolipoma is a common benign renal tumor. It is associated with Tuberous Sclerosis Complex (TSC) in 20% of patients. Angiomyolipomas are classically multiple, bilateral, and growing; they may lead to complications such as Wunderlich syndrome or, in rare cases, to venous extension. Observation. a 74-year-old woman with TSC presented with an angiomyolipoma of the right kidney with inferior vena cava (IVC) fatty thrombus. She underwent partial nephrectomy and thrombectomy. After a 7-year follow-up there was no evidence of recurrence or metastasis and her renal function was preserved. Review of Literature. It is the 44th reported angiomyolipoma associated with IVC thrombus. The mean size of angiomyolipomas was 86.1 mm and 67.4% of patients were symptomatic. Pulmonary embolism was found in 6 patients. There were 2 cases of recurrence/metastatic outcome after radical nephrectomy and thrombectomy. They were associated with epithelioid form. The mean size of epithelioid tumors was significantly bigger than in classical angiomyolipomas (127.1 mm versus 82.6 mm, P = 0.037). With a median follow-up of 12 months, 91.3% of patients were recurrence and metastasis free, with 3 cases of nephron sparing surgery. Conclusion. Nephron sparing surgery for angiomyolipoma with IVC fatty thrombus can be safely performed in TSC, even in sporadic angiomyolipoma.

Contemporary diagnosis and management of renal angiomyolipoma

PURPOSE

We present a comprehensive resource that summarizes contemporary advances relevant to the clinical management of renal angiomyolipoma.

MATERIALS AND METHODS

A MEDLINE search was done using the key words angiomyolipoma, hemangioma or lipoma and kidney neoplasm, and therapeutic embolization. References from these articles were reviewed to identify additional relevant source material. We identified 13 series published since 1986 comprising 336 patients as well as 24 reports of therapeutic embolization for angiomyolipoma, comprising 76 patients. To our knowledge we report the largest compilation series to date.

RESULTS

Angiomyolipoma is generally benign, although an uncommon subtype (epithelioid angiomyolipoma) may behave more aggressively. Tuberous sclerosis associated angiomyolipoma tends to be larger, multiple and more likely to cause spontaneous hemorrhage than the sporadic entity. Tumors that hemorrhage tend to be larger. Computerized tomography or magnetic resonance is usually sufficient for diagnosis. Biopsy is rarely useful. Primary indications for intervention include symptoms such as pain or bleeding or suspicion of malignancy. Prophylactic intervention is justifiable for large tumors, in females of childbearing age or in patients in whom followup or access to emergency care may be inadequate. Recent advances that have affected management include improved understanding of tuberous sclerosis complex and angiomyolipoma genetics, the identification of molecular markers that facilitate histopathological diagnosis, and the refinement of embolization and partial nephrectomy techniques.

CONCLUSIONS

Although some cases of angiomyolipoma may require complete nephrectomy, most can be managed by conservative nephron sparing approaches. Ongoing research into the molecular biology and clinical behavior of angiomyolipoma may improve our ability to manage these lesions.