Management Of Renal Angiomyolipoma Research Articles

An update on recent developments in rupture of renal angiomyolipoma

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.

The Role of Interventional Radiology Techniques in the Management of Renal Angiomyolipomas.

Although benign, renal angiomyolipoma (AML) may lead to serious complications without appropriate management. The purpose of this review is to describe the role of and evidence for interventional radiology techniques in the management of patients with AML. For patients with renal masses and non-diagnostic imaging studies, image-guided percutaneous biopsy is found to be highly accurate and useful in directing patient management. Once the diagnosis of AML has been made based on either imaging or biopsy, arterial embolization of tumors that are symptomatic or >4cm has been demonstrated to reduce the risk of hemorrhage as well as tumor size. Percutaneous ablation devices have been proposed as alternative strategies but remain investigational. The utility of interventional radiology techniques including percutaneous core needle biopsy and prophylactic super-selective arterial embolization is safe and effective management strategies for patients presenting with AML tumors.

Contemporary management of renal angiomyolipomas

Active treatment of renal angiomyolipomas was historically recommended when tumors measured greater than 4 cm or grew rapidly because of the risk of hemorrhage. However, contemporary data suggests that some larger renal angiomyolipomas can also be managed safely with active surveillance.

The emergency treatment of renal angiomyolipoma with spontaneous rupture and hemorrhage (Report of 24 cases)

Objectives To investigate the emergency treatment of renal angiomyolipoma with spontaneous rupture and hemorrhage. Methods A retrospective analysis was made on the clinical data and follow–up of 24 cases of renal angiomyolipoma with spontaneous rupture and hemorrhage.Preoperative ultrasonography and CT scanning had been underwent in all the cases. Renal angiomyolipoma with spontaneous rupture and hemorrhage was diagnosed in 22 patients and renal cell carcinoma with hemorrhage could not be ruled out in the other 2 patients. 3 patients were treated conservatively and 4 patients were treated with selective renal arterial embolization. The other 17 patients were managed with emergency surgical intervation. Results In 3 cases of conservative treatment, 1 case was stable, other 2 cases failed and received sugical intervation. 4 cases were embolized successfully, then hemorrhage disappeared. Operation was performed in 17 patients.Nephrectomy was performed in 4 cases. 13 cases were treated with nephron–sparing surgery (NSS).5 caess underwent retroperitoneal laparoscopic surgery and 8 cases were performed open surgery.All the patients were confirmed to be renal angiomyolipoma with rupture and hemorrhage by pathological examination after operation. 24 cases were followed up for 3 to 72 months, no case was recurred and metastasized. Conclusions Ultrasonography and CT scanning are important methods to diagnose renal angiomyolipoma with rupture. The management of renal angiomyolipoma with rupture includes conservative methods, selective renal arterial embolization and emergency surgical intervation. Key words: Kidney Neoplasms; Angiomyoma; Lipoma; Rupture, Spontaneous; Hemorrhage

Differentiation of Sporadic Versus Tuberous Sclerosis Complex-Associated Angiomyolipoma.

We review the imaging of renal angiomyolipomas, including differentiation of tuberous sclerosis complex (TSC)-associated and sporadic renal angiomyolipomas and other solid renal tumors. We also focus on radiologic interventions and molecular targeting of the TSC genetic pathway. Imaging plays a central role in the diagnosis and management of renal angiomyolipomas. It provides essential information to make the best therapeutic decisions about the interventional and pharmacologic options to help prevent bleeding and preserve functional parenchyma.

Transarterial Embolization of Angiomyolipoma: A Systematic Review

Transarterial embolization is increasingly used in the management of renal angiomyolipoma. The level of evidence establishing the safety and efficacy of transarterial embolization has not increased in parallel. Using the MOOSE (Meta-analysis Of Observational Studies in Epidemiology) criteria a systematic review of transarterial embolization of angiomyolipoma was performed to establish procedural safety and efficacy. A MEDLINE® PubMed® search revealed 1,739 publications, of which 31 studies met eligibility criteria. A total of 524 cases of transarterial embolization of angiomyolipoma were included in analysis. Self-limiting post-embolization syndrome developed following 35.9% of embolizations and further morbidity developed in 6.9%. No procedural mortality was reported. At a mean followup of 39 months the mean size reduction was 3.4 cm (-38.3% of angiomyolipoma diameter). Unplanned repeat embolization or surgery was required in 20.9% of cases during this period. The most frequent indications for repeat procedures included angiomyolipoma revascularization in 30.0% of cases, unchanged or increasing size in 22.6%, refractory or recurring symptoms in 16.7% and representation with acute retroperitoneal hemorrhage in 14.3%. Treatment included a combination of 2 or more embolic agents in 46.8% of cases, ethanol monotherapy in 41.7%, coil monotherapy in 6.2% and foam or microparticle monotherapy in 5.2%. Transarterial embolization of angiomyolipoma demonstrates low rates of mortality and serious complications. Re-treatment rates and size reduction at a mean followup of 39 months are presented. Longitudinal data assessing long-term size reduction and re-treatment rates are lacking. Recommendations guiding the indications for transarterial embolization and clear followup require further longitudinal data.

C149: Optimal management of renal angiomyolipomas, our experience in 10 years series

C149: Optimal management of renal angiomyolipomas, our experience in 10 years series

Contemporary Experience in the Management of Angiomyolipoma

We review our single center experience in the management of renal angiomyolipoma (AML) in patients who were treated with active surveillance (AS) or invasive treatment protocols. A prospectively evaluated database was reviewed, and we identified 91 patients with the diagnosis of renal AML who presented between June 1985 and February 2009. Patient characteristics, clinical presentation, treatment modalities, and patient outcomes were evaluated. Patients on AS were analyzed for successful completion of the surveillance protocol considering age, symptomatic presentation, and tumor size as potential predictors of invasive treatment. A total of 91 patients with AMLs were identified. The mean patient age was 57 years. Seventy-three (83.9%) patients presented incidentally, and 14 (16%) patients were symptomatic at presentation. Forty-five patients were treated with AS, 4 underwent embolization, and 38 patients had extirpative surgery. After a median follow-up of 54.8 months (range 0.2-211.7 mos), there was a mean growth rate of 0.088 cm/year in the group who were treated with AS. AS failed in three patients. Two patients had retroperitoneal bleeding during the observation period, and one patient manifested an expeditious growth rate of 0.7 cm/year and underwent a radical nephrectomy. AML is a renal tumor that usually exhibits a benign course. Surgical removal and embolization are the standard invasive treatment modalities. AS for AMLs is associated with a slow and consistent growth rate (0.088 cm/year), typically has minimal morbidity, and is a reasonable option in selected patients. Symptomatic presentation and size (> 3 cm) are not predictive for necessitating an invasive procedure.

MP-04.07: The Long Term Outcome of Management of Renal Angiomyolipoma (AML) with Selective Renal Arterial Embolization (SAE)

MP-04.07: The Long Term Outcome of Management of Renal Angiomyolipoma (AML) with Selective Renal Arterial Embolization (SAE)

The management of renal angiomyolipomas in a patient with tuberous sclerosis

A 17-year-old girl, who was diagnosed with tuberous sclerosis in infancy, presented with multiple bilateral renal masses, the largest of which was 6.0 cm in diameter on the left side. History and physical examination, ultrasonography, MRI, CT, magnetic resonance angiography, and measurement of serial creatinine levels. Bilateral angiomyolipomas.Management Observation, serial imaging, embolization and infarction.

Abstract No. 322 EE: Transarterial Management of Renal Angiomyolipomas in Elective and Emergency Settings

Abstract No. 322 EE: Transarterial Management of Renal Angiomyolipomas in Elective and Emergency Settings

Changing Trends in Presentation, Diagnosis and Management of Renal Angiomyolipoma: Comparison of Sporadic and Tuberous Sclerosis Complex-associated Forms

To evaluate the changing management of sporadic renal angiomyolipoma and renal angiomyolipoma associated with the tuberous sclerosis complex (TSC) during the past 16 years. We retrospectively reviewed the charts of 60 patients with angiomyolipoma seen at our institutions. The median age at presentation was 45 years (range 7-78). The presentation was pain in 30 patients and hematuria in 13; it was incidentally discovered in 17 patients. Of the 60 patients, 43 were females. TSC was present in 14 patients. The median tumor size was 4 cm (range 0.3-40, mean 6.5 +/- 1.1). Of the 60 patients, 31 were followed up expectantly. Surgery or intervention was needed for 29 patients to control hemorrhage or relieve pain or because of the suspicion of malignancy. Of these 29 patients, 12 underwent nephrectomy, 11 partial nephrectomy, and 6 embolization. The patients treated for hemorrhage had a median tumor diameter of 11 cm (range 2-21). Patients were followed up for a mean of 39.3 +/- 5.4 months. The lesions grew an average of 4.7 +/- 3.4 cm for TSC tumors and 0.6 +/- 0.2 cm for sporadic angiomyolipoma tumors. None of the patients developed renal impairment. Patients with TSC presented at a younger age, had larger and bilateral lesions, and were more symptomatic during follow-up. In the past 6 years, a significant trend was seen toward finding tumors in asymptomatic patients and toward the use of conservative or interventional (embolization) treatment. Renal angiomyolipoma has a slow growth rate. The preservation of renal function was noted in all our patients. A recent shift was noted toward finding smaller tumors in asymptomatic patients and the use of conservative and interventional treatment.

Clinical Correlates of Renal Angiomyolipoma Subtypes in 209 Patients: Classic, Fat Poor, Tuberous Sclerosis Associated and Epithelioid

Angiomyolipomas classically present radiographically as fat containing lesions but some fail to demonstrate fat content. Histologically confirmed angiomyolipomas uniformly follow a benign course but rare epithelioid variants of angiomyolipoma can recur and metastasize. We investigated the clinical, radiographic and histological characteristics of each angiomyolipoma subtype. Pertinent data were recorded for 209 patients surgically treated for angiomyolipoma in 219 kidneys from 1981 to 2007. Classic and fat poor angiomyolipomas were classified radiographically based on the presence or absence of fat and classified histologically based on the presence of triphasic, monophasic or epithelioid histology. Median radiographic size was 3.2, 4.9 and 10 cm in patients with a single angiomyolipoma (59% of patients), multiple angiomyolipomas and tuberous sclerosis (probable or definite), respectively. In these 3 groups 65%, 47% and 33% of lesions were not suspected radiographically (fat poor angiomyolipoma). Fat poor angiomyolipomas were more commonly single, smaller and in older patients. Triphasic histology was evident in 76% of angiomyolipomas with 16% demonstrating a predominance of 1 component and 8% containing epithelioid features. Despite potentially aggressive findings in 18% (eg presence within the perinephric fat, lymph node involvement) no angiomyolipoma recurred during a mean followup of 3.4 years (range 0 to 24). A total of 28 (13%) patients with angiomyolipoma had concomitant renal cell carcinoma. A surprisingly high number of resected angiomyolipomas was not suspected radiographically indicating the importance of precise radiographic characterization to minimize nephrectomy for fat poor angiomyolipoma, which should remain a research priority. In this sizeable single institution series no triphasic, monophasic or epithelioid angiomyolipoma recurred despite potentially aggressive findings in a substantial proportion of cases.

Hormone Receptor Expression in Renal Angiomyolipoma: Clinicopathologic Correlation

Although renal angiomyolipoma (AML) occurs more commonly in females than males, the origin of this difference in incidence by sex is unknown. Therefore, we investigated the expression of the androgen receptor (AR), estrogen receptor subtypes alpha (ERalpha) and beta (ERbeta), progesterone receptor, and the enzyme aromatase in renal AML. We evaluated specimens from 110 patients who had undergone resection of a renal AML, including 90 women and 20 men. Immunohistochemistry was performed using monoclonal antibodies on paraffin-embedded tissue sections. Expression was correlated with patient demographics and tumor pathologic features. ERbeta was expressed in 100% (106 of 106) of the AML specimens evaluated. Of the 104 specimens that could be assessed for the AR, 82 (79%) demonstrated staining. Of 110 lesions, 31 (28%), 42 (38%), and 11 (10%) expressed ERalpha, progesterone receptor, and aromatase, respectively. The level of ERbeta expression was not associated with patient age (P = 0.92), sex (P = 0.82), a diagnosis of tuberous sclerosis (P = 0.56), or histologic subtype of AML (P = 0.94). A trend was found toward increased AR expression in men (P = 0.069) and younger patients (P = 0.052), and ERalpha was expressed in the AML specimens from 5 (71%) of 7 patients with tuberous sclerosis compared with 26 (25%) of 103 without tuberous sclerosis (P = 0.018). Both AR and ERalpha expression were more common in the triphasic subtype of AML than in the lipomatous tumors (P = 0.046 for both). The results of our study have shown that ERbeta expression is ubiquitous in renal AML, and the AR is found in most tumors. ERalpha and progesterone receptor were expressed in approximately one third of cases. These data suggest a potential role for hormones in the pathogenesis and management of renal AML.

Ethanol and Polyvinyl Alcohol Mixture for Transcatheter Embolization of Renal Angiomyolipoma

The purpose of this study was to assess the immediate and midterm effects of embolization of the angiogenic component of renal angiomyolipoma in which a mixture of ethanol and polyvinyl alcohol is used as a permanent obliterator. Seventeen patients with 18 renal angiomyolipomas (size range, 5.5-20 cm; mean size, 10 cm) were treated with transcatheter embolization over an 8-year period. Embolization was performed with a mixture of 96% ethanol and polyvinyl alcohol particles. Follow-up with CT (mean follow-up period, 22.4 months) and one (mean, 14 months) or two (mean, 27 months) angiographic examinations were conducted to evaluate changes in the size of the tumor and to look for recurrence of the angiogenic component. All initial angiograms showed the characteristic tortuous, hypervascular, and aneurysm-forming angiogenic component. Immediate complete obliteration was achieved in 17 tumors (94.4% technical success rate). There was one partial technical failure. Mean tumor size was reduced to 7.6 cm (mean size reduction, 24%). Fourteen patients with 15 tumors underwent one angiographic follow-up examination (mean time after treatment, 14 months), and four patients underwent two angiographic follow-up examinations (mean time after treatment, 27 months). Reduction of the angiogenic component occurred in 10 (66.6%) of the tumors and complete obliteration in five (33.3%) of the tumors. No retroperitoneal hemorrhage or tumor growth was seen during the follow-up period. No complications were encountered. We found a mixture of ethanol and polyvinyl alcohol an efficient embolizing agent with a sustained midterm effect in the management of renal angiomyolipoma. Repeated embolization was needed in tumors with a large angiogenic component. Tumor shrinkage after embolization was minimal.

Contemporary diagnosis and management of renal angiomyolipoma.

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

Management of renal angiomyolipoma in patients with tuberous sclerosis complex

Renal angiomyolipomas are common in patients with tuberous sclerosis complex (TSC), and the risk of severe haemorrhage from these angiomyolipomas can become substantial. This case illustrates a potentially life-threatening condition due to the development of a large aneurysm within an angiomyolipoma, which was discovered within 14 months of her screening renal ultrasound scan. Renal arterial embolisation and renal sparing surgery resulted in good recovery. Clear guidelines for the screening, surveillance, and treatment of angiomyolipomas in patients with TSC are required. This includes the appropriate frequency of surveillance for patients in different age groups and at different stages of angiomyolipoma development, based on a growing knowledge of the natural history of this condition, since growth of renal angiomyolipomas can be rapid and asymptomatic. Computed tomography or magnetic resonance imaging may be required to demonstrate complications in large lesions, as three ultrasound examinations in this patient failed to detect the large aneurysm which had developed. Angiogenesis inhibitors could potentially play a role in preventing the development of angiomyolipomas, which could improve the prognosis for patients with TSC and therefore warrants investigation through phase II/III clinical trials.

Contemporary Diagnosis and Management of Renal Angiomyolipoma

Contemporary Diagnosis and Management of Renal Angiomyolipoma

Management of Renal Angiomyolipoma in Complex Clinical Situations

Renal angiomyolipoma (AML) is associated with complex clinical situations such as tumour in a solitary kidney, bilateral, large or multicentric tumours or those associated with tuberous sclerosis (TS) or pregnancy. Management in these situations may be challenging. Fifteen patients (20 kidneys) were admitted with symptomatic AML over last 10 years. Eleven patients had one or the other complicating factor. Ten patients had a tumour of >10 cm, 4 had TS, 5 had multiple and bilateral tumours, 1 patient was pregnant and 1 had a solitary functioning kidney. With the newer imaging modalities correct diagnosis was possible in 12 cases and renal cell carcinoma (RCC) was suspected in 3 cases. Selective angioembolization (SAE) was done in 3 patients, which successfully controlled bleeding in all. Nephron-sparing surgery (NSS) was performed in 5 patients. Total nephrectomy was done in 4 cases, in 3 due to suspicion of RCC and in 1 due to extensive involvement of the kidney. Three patients with multiple and bilateral tumours were chosen for conservative treatment and none developed recurrence of bleeding on strict follow-up. In a pregnant patient, bleeding was successfully controlled with angioembolization. However, 1 patient with a solitary functioning kidney with large-sized tumour (20 × 18 cm) underwent NSS. In conclusion, the basis of management of AML is preservation of renal tissue, which can be effectively achieved with SAE or NSS. In a solitary functioning kidney, NSS or SAE is the ideal treatment, if feasible. The patients in the TS group are usually more complicated and require life-long follow-up after initial management with NSS or SAE. Pregnant AML patients can be safely managed with SAE. Conservative treatment without any intervention and regular follow-up may be more helpful in some patients with multiple, bilateral extensive tumours.

Management of renal angiomyolipoma: a report of 53 cases

Correspondence to Mr Christopher R. Chapple, Urology Research Department, Royal Hallamshire Hospital, Glossop Road, Sheffield S10 2JF, UK. Tel: +44 114 271 2791; fax: +44 114 279 8318 University of Vienna, Vienna, Austria