The radiological diagnosis and treatment of renal angiomyolipoma-current status

Determinants of conventional and contrast-enhanced ultrasound diagnosis of fat-poor angiomyolipoma <5 cm

Purpose

This study aims to assess the diagnostic efficacy of conventional ultrasound (CUS) and contrast-enhanced ultrasound (CEUS) in detecting fat-poor angiomyolipomas(AML) with dimensions less than 5 cm. Additionally, the study seeks to identify independent indicators for predicting the presence of fat-poor AML.

Methods

We conducted a retrospective analysis of patients diagnosed with renal AML and renal cell carcinoma, who were admitted and underwent surgery at Fujian Provincial Hospital from January 2013 to October 2023. A total of 154 renal tumors were included (104 renal cell carcinomas and 50 fat-poor AMLs). Prior to radical or partial nephrectomy, these patients underwent both CUS and CEUS examinations. We systematically analyzed the features observed in CUS and CEUS, identified independent factors through multifactorial regression analysis, and evaluated diagnostic efficacy by calculating the area under the curve (AUC).

Results

Univariate analysis revealed significant distinctions in fat-poor AML concerning gender, age, morphology, internal hyperechoic features (starry-sky sign, crescent sign), enhancement uniformity, and delayed enhancement, all displaying significance compared to renal cell carcinoma (RCC) (p < 0.05). Multivariate analysis demonstrated that internal hyperechoic features (p < 0.01, Odds Ratio [OR] = 0.003, 95% Confidence Interval [CI]: 0.000-0.0028) and enhancement uniformity (p < 0.01, OR = 0.016, 95% CI: 0.001-0.229) independently predicted fat-poor AML. The Receiver Operating Characteristic (ROC) curve's area under the curve (AUC) for internal hyperechoic features (starry-sky sign, crescent sign) was 0.88 (95% CI: 0.80-0.95), with a sensitivity of 78.00%, specificity of 97.12%, positive predictive value of 92.85%, and negative predictive value of 90.18%. Conversely, the ROC curve AUC for enhancement uniformity was 0.70 (95% CI: 0.62-0.78), with a sensitivity of 96.00%, specificity of 44.23%, positive predictive value of 45.28%, and negative predictive value of 95.83%.

Conclusion

This study suggests that both CUS and CEUS possess discriminative value in differentiating fat-poor AMLs from RCCs. Notably, internal hyperechoic features (starry-sky sign, crescent sign) and uniform enhancement within renal tumors emerge as potential independent indicators for predicting fat-poor AML.

Safety profile of abdominal magnetic resonance imaging (MRI) performed for renal disease surveillance in tuberous sclerosis complex patients with vagus nerve stimulation: Safety of MRI for TSC Patients with VNS

INTRODUCTION

Individuals with tuberous sclerosis complex (TSC) often present with refractory epilepsy and may be undergoing treatment with vagus nerve stimulation (VNS) to control seizures. Surveillance magnetic resonance imaging (MRI) is necessary to monitor for the renal angiomyolipomas associated with TSC; however, MRI of the abdomen is not approved for patients withVNS therapy. We have many TSC patients with refractory epilelpsy who benefitted from VNS therapy, so we developed an MRI protocol that allows MRI of the abdomen to be performed in these patients to permit safe imaging of their kidneys. Here we report our results using this protocol.

METHODS

We performed a retrospective review for all TSC patients seen from 01/01/1997 to 10/01/2022 at a single center to determine VNS implantation status. Patients with VNS implants and abdomen imaging performed according to the protocol for kidney surveillance were included.

RESULTS

Sixteen patients with 48 total MRIs of the abdomen were found: 34 (71 %) scans were conducted under sedation and 14 (29 %) without sedation. None of the patients reported any adverse effects (pain or discomfort). No instances of VNS dysfunction were noted when re-interrogating the device immediately after completion of the imaging studies or at later neurology follow-up appointments. All MRI scans were of good quality for interpretation.

CONCLUSION

Abdominal MRIs performed in typical VNS exclusion zones were not associated with adverse events or VNS dysfunction. We believe this protocol is safe and permits the best method for monitoring renal disease in TSC patients with VNS.

Surgical excision of recurrent renal angiomyolipoma after previous embolization and nephron-sparing surgery - A case report

INTRODUCTION

Renal angiomyolipoma is the most common benign kidney tumor, representing 1-3 % of solid renal tumors. Despite its benign nature, it can be associated with lethal hemorrhage, and can also show signs of local extension mimicking malignant tumors. The cornerstone of treatment remains angioembolization and nephron sparing surgery.

PRESENTATION OF CASE

A 51-year-old Nepalese woman presented to the emergency department with acute abdominal pain and signs of hypovolemic shock. She was managed with resuscitation, followed by angioembolization of a left renal artery pseudoaneurysm. A few months later, she underwent laparoscopic nephron-sparing surgery. One year later, she had excision of a recurrent left angiomyolipoma. Both the initial and final histologic examinations confirmed the diagnosis of classic variant renal angiomyolipoma.

DISCUSSION

Although transcatheter angioembolization is the treatment of choice for bleeding angiomyolipoma, there is a higher likelihood of re-embolization and the need for surgical excision. Therefore, surgeons should carefully consider treatment options and discuss the pros and cons of each with the patient and their family, taking into account the available infrastructure and expertise.

CONCLUSION

We report a rare and interesting case of acutely bleeding angiomyolipoma. The patient was successfully treated with angioembolization followed by laparoscopic nephron-sparing surgery. However, the tumor recurred a year later, necessitating conversion to open nephron-sparing surgery.

When flank pain leads to fainting: a case of a ruptured angiomyolipoma diagnosed by point-of-care ultrasound

BACKGROUND

Acute flank pain is a common presentation in the Emergency Department (ED). Point-of-care ultrasound (PoCUS) has emerged as an invaluable tool in the evaluation of acute flank pain and provides real-time images resulting in the early identification of the underlying pathology.

CASE REPORT

Here we report a case of a young lady presented to the ED with a complaint of right flank pain followed by a syncopal episode. The diagnosis of ruptured angiomyolipoma was made using a PoCUS and an immediate consult to interventional radiology and urology was provided.

CONCLUSION

This case highlights the importance of PoCUS in assessing patients presented to the ED with acute flank pain. Its incorporation into clinical practice promises to revolutionize the approach to renal emergencies, emphasizing its important role in delivering timely and effective care.

The extent of kidney involvement in paediatric tuberous sclerosis complex

BACKGROUND

Tuberous sclerosis (TSC)-associated kidney disease is a leading cause of mortality in adults with TSC. This study aimed to understand TSC features in children, particularly kidney involvement, to inform clinical care for this specific group.

METHODS

This retrospective cohort study included all paediatric (< 19 years) TSC cases at a large tertiary paediatric nephrology centre. Relevant data were collected from patients' records, statistical analyses were performed to identify associations between variables, survival probabilities were estimated with Kaplan‒Meier curves, and log-rank tests were conducted to assess survival differences among genetic mutations.

RESULTS

A total of 182 children with TSC were included. Among the 145 children with available kidney imaging data, 78.6% (114/145) exhibited kidney lesions. Angiomyolipomas (AMLs) were significantly more prevalent in the TSC2 mutation group (p = 0.018). Children with TSC2 mutations generally had poorer lesion-free survival than those with TSC1 mutations, but this difference was only significant for AMLs (p = 0.030). The change in size of largest AMLs increased with age and doubled in children above 9 years; a similar pattern was observed when stratified by genetic mutation. In contrast, kidney cysts exhibited two peaks: one in children under 5 years (2.31 mm/year) and the second in children between 15-19 years (2.82 mm/year). Chronic kidney disease was observed in 12.3% (10/81) of children, and high-risk AMLs above 3 cm were observed in 9% (13/145).

CONCLUSIONS

While TSC kidney disease emerges later in the disease course than neurological features, our findings emphasise the importance of kidney surveillance during childhood, including routine kidney imaging, kidney function, and blood pressure monitoring.

Spectrum of Renal Tumors Other Than Renal Cell Carcinoma with Emphasis on Cytomorphological, Immunohistochemical, and Cytogenetic Study

Background

The role of fine needle aspiration cytology (FNAC) in the diagnosis of renal malignancies is established and has been getting more precise and important over a period of time. Knowledge of the pathology of uncommon renal neoplasms along with radiological and clinical correlations often aids in correct diagnosis.

Aims

The present study aims to describe the cytomorphological and immunohistochemical findings in the varied spectrum of renal tumors, other than renal cell carcinomas (RCC).

Materials and Methods

Data of 238 cases of ultrasound-guided renal FNAC performed in our tertiary cancer institute over 4 years were collected from the department registry. All nondiagnostic cases and cases diagnosed as RCC were excluded from the study, so 57 cases of renal tumors were reviewed along with the cell blocks and ancillary studies.

Results

Out of the 57 cases, 35 cases were primary renal neoplasms, which included renal oncocytoma (3.5%), angiomyolipoma (3.5%), rhabdoid tumor (1.8%), Wilms tumor (28.0%), Ewing sarcoma (3.5%), urothelial carcinoma (8.8%), and small round cell tumor unclassified (12.3%). Twenty two cases were metastatic tumors, which included hematolymphoid neoplasm (14%) and metastatic carcinomas (24.6%) from various other primary carcinomas.

Conclusion

Our study shows that renal FNAC is safe and fairly accurate in diagnosing a wide spectrum of renal tumors and has high diagnostic accuracy, when performed along with cell block and immunohistochemistry. Awareness of the pathology of uncommon renal tumors along with relevant clinical history and radiological findings may aid in identifying the type of tumor for further appropriate management.

Comparison of Superselective Renal Artery Embolization versus Retroperitoneal Laparoscopic Partial Nephrectomy in Ruptured Hemorrhagic Renal Angiomyolipoma: A Single-Center Study

PURPOSE

To analyze the clinical efficacy of superselective renal artery embolization and retroperitoneal laparoscopic partial nephrectomy for the treatment of ruptured hemorrhagic renal angiomyolipoma and to provide a reference for the selection of treatment methods for ruptured hemorrhagic renal angiomyolipoma.

METHODS

A retrospective analysis was conducted on the clinical data of 24 patients who were diagnosed with ruptured hemorrhagic renal angiomyolipoma at the Second Hospital of Tianjin Medical University between January 2019 and December 2021. Among them, 10 patients were treated with superselective arterial embolization (SAE), and 14 patients were treated with retroperitoneal laparoscopic part nephrectomy (RLPN). The differences between the two treatment methods in terms of hospital stay, hospital costs, anesthesia method, operation time, intraoperative blood loss, postoperative bed rest time, antibiotic dosage, postoperative complication rate, tumor diameter changes, creatinine value changes, hemoglobin value changes, tumor recurrence rate, and reoperation rate were compared.

RESULTS

All patients completed the treatment and were discharged. There were no significant differences in length of hospital stay, hospital costs, creatinine change values, or postoperative complication rates between the two groups (p > 0.05). However, there were statistically significant differences (p < 0.05) in surgical time (85.50 ± 19.94 min vs. 141.07 ± 76.33 min), intraoperative blood loss (21.50 ± 14.72 mL vs. 153.57 ± 97.00 mL), postoperative bed rest time (22.7 ± 1.56 h vs. 41.21 ± 3.57 h), preoperative hemoglobin levels (94.7 ± 23.62 g/L vs. 113.79 ± 17.83 g/L), and hemoglobin changes (-6.60 ± 10.36 g/L vs. -15.21 ± 8.79 g/L) between the two groups. Both groups of patients had an average follow-up period of 22 months, and patients in the SAE group had a mean reduction of 3.33 cm in tumor diameter within the follow-up period compared with the pre-embolization period (p < 0.05). None of the patients in the SAE group experienced rebleeding, and there was no tumor recurrence in either group.

CONCLUSION

SAE and RLPN are effective treatments for ruptured renal angiomyolipoma with good outcomes. Furthermore, compared to RLPN, SAE offers advantages such as simplicity of operation, minimal trauma, shorter surgical time, minimal impact on hemoglobin levels, shorter bed rest time, faster postoperative recovery, and maximal preservation of renal units.

Bilateral renal angiomyolipoma with venous invasion: A case report

Renal angiomyolipoma (AML) is a rare benign tumor of the kidney, often detected incidentally on radiological images as the presence of macroscopic fat characterizes them. In the majority of the cases, they are usually sporadic. Despite their benign nature, venous invasion, a rare occurrence in renal AMLs, poses management challenges. We present a case of bilateral renal AML in a 52-year-old female with a right renal vein and hepatic inferior vena cava invasion.

Sirolimus can promote the disappearance of renal angiomyolipoma associated with tuberous sclerosis complex: a prospective cohort study

BACKGROUND

Renal angiomyolipoma (RAML) is the most common kidney lesion in patients with tuberous sclerosis complex (TSC), affecting about 80% of patients. It is a benign tumor that grows over time, usually bilaterally, and can easily lead to kidney complications such as acute hemorrhage. Herein, we investigated the efficacy and safety of sirolimus in children with TSC-associated RAML and explored the factors affecting tumor disappearance under sirolimus treatment through subgroup analysis.

METHODS

A prospective cohort study was conducted. Sirolimus was initiated at 1 mg/(m2 × day), and dose adjustments were made by a 2-week titration period to attain a trough blood concentration of 5-10 ng/mL. The disappearance of RAML in children after sirolimus treatment was observed, and Cox regression was used to screen the factors affecting tumor disappearance.

RESULTS

One hundred and twenty-six patients who met the criteria were analyzed. After 3 months, 6 months, 12 months, and 24 months of follow-up, tumors disappeared in 18 (14.3%), 30 (23.8%), 39 (31.0%), and 42 (33.3%) children, respectively. Tumors disappeared in 50 (39.7%) children by the last visit of each individual, and 30 (60%) of them occurred within 6 months. The multivariate Cox regression analysis showed that patients with a smaller maximum tumor diameter at baseline had a higher tumor disappearance rate. Thirty-six (29%) patients had stomatitis during the entire treatment period, and no serious adverse reactions were observed.

CONCLUSIONS

Sirolimus could promote the disappearance of TSC-related RAML. The disappearance rate was correlated with the maximum diameter at baseline, and the smaller the tumor was, the higher the disappearance rate. It is well tolerated in the treatment of RAML associated with TSC.

Natural History and Management of Ultrasound-detected Small Renal Angiomyolipoma

Background

Recent advances in imaging methods increased the incidental detection of small renal angiomyolipoma (AML). However, guidelines for managing small AML are lacking, and decisions about imaging frequency and timing of intervention are made on an individual basis. This study aims to investigate the clinical behavior of small sporadic AML and propose an optimal follow-up strategy.

Methods

The study is a retrospective analysis of 168 individuals who had hyperechoic lesions, suggestive of AML detected during abdominal ultrasound as a part of their health checkup. The clinical information of the individuals, including tumor characteristics and renal function, was reviewed. Statistical analysis was performed to identify factors associated with tumor growth and renal function.

Results

Most AMLs were small (≤20 mm) and did not exhibit malignant characteristics. The tumors showed a slow growth rate, with a mean growth rate of 0.24 mm/year. Only a small proportion of cases (1.2%) required intervention due to significant enlargement. Factors such as tumor size and gender were not significantly associated with tumor growth rate or renal function. However, younger patients showed a higher tumor growth rate and a more pronounced decline in renal function.

Conclusion

Small sporadic AMLs have a slow growth rate and little risk of malignancy. Neither tumor size nor gender was predictive factors for tumor growth or renal function. Nevertheless, close monitoring of tumor growth and renal function is advised, particularly in younger patients. This study highlights the need for further research and guidelines to establish an optimal surveillance protocol for small AMLs.

Renal angiomyolipoma: from imaging to intervention

A high volume of cross-sectional imaging has created a window of opportunity for radiologists to identify renal angiomyolipomas (AMLs). The purpose of this review is to help the reader recognise the spectrum of renal AML appearances using different imaging methods and to gain an understanding of the classic and atypical features for appropriate lesion characterisation. Risk factors for AML growth and rupture will be highlighted. An overview of the imaging features of acute AML rupture will be provided, principally relating to computed tomography (CT) assessment. A series of cases will be presented, including a case of peripartum renal AML rupture during Caesarean section leading to diagnostic dilemma. The indications for intervention and available treatment options will be considered: medical therapy, surgery, and interventional radiology (IR) techniques including their pros and cons. Emergency interventional radiology management with selective transarterial embolisation will be presented and analysed in relation to technique, angiographic appearances (pre and post embolisation) and associated complications.

Bilateral renal angiomyolipoma with left renal artery aneurysm in tuberous sclerosis: case report and literature review

Introduction and importance

Tuberous sclerosis disorder (TSD) is a rare genetic disease that causes abnormal growths or tumors in various organs of the body. They are usually benign and asymptomatic. However, severe, rapidly growing tuberous sclerosis can be fatal. Renal angiomyolipomas are commonly associated with TSD, which can be further worsened by the presence of aneurysms and put the patient at risk for life-threatening hemorrhage.

Case presentation

A 29-year-old female presented to the emergency room complaining of right flank pain with an unknown past medical history of tuberous sclerosis. The patient was suspected to have TSD as she fulfilled one of the major features of TSD required to establish a possible diagnosis. On computed tomography scan imaging, bilateral fat-density nodules were revealed in both kidneys. The largest is 7 cm in the left kidney, located at the upper pole, and was associated with a bleeding aneurysm measuring 4 cm in diameter. While the other fatty nodule was recorded at 6 cm in the right kidney at the lower pole.

Clinical discussion

After evaluation, the patient was planned for diagnostic catheterization of the left kidney, through which selective angiography of the left kidney was done, and eventually, selective embolization of the branch supplying the left angiomyolipoma was performed.

Conclusion

The authors finally conclude that thorough investigations, including systemic manifestations, must be taken into consideration when suspecting tuberous sclerosis, and a conservative approach must always be prioritized before taking any decision toward invasive approaches.

Small Tumor, Major Complication: A Case of Spontaneous Perinephric Hematoma From a Small Renal Angiomyolipoma

A renal angiomyolipoma is a benign kidney tumor composed of muscle, fat, and blood vessels. It is the most common benign kidney tumor, and it affects women more frequently than men. Angiomyolipomas can be small and asymptomatic, or they can be large, presenting with symptoms such as discomfort, hematuria, and hypertension. Occasionally, the rupture of an angiomyolipoma can cause a perinephric hematoma. This case report discusses a patient who developed a spontaneous large perinephric hematoma alongside a small renal angiomyolipoma. Aneurysm was seen on imaging. Angioembolization was successfully used for treatment. We explore the significance of the presence or absence of an aneurysm in predicting the risk of hemorrhage, particularly in association with small lesions. Angioembolization is an excellent choice for treating angiomyolipomas associated with significant hematomas.

Factors predicting the active treatment of renal angiomyolipoma: 30 years of experience in two tertiary referral centers

Introduction and objective

This study aimed to identify clinical features representing predictive factors of active treatment (AT) compared to active surveillance (AS) for renal angiomyolipoma (AML).

Patients and methods

From 1990 to 2020, patients referred to two institutions for a renal mass and diagnosed with an AML based on typical features on CT were included in the analysis. The study population was divided into two groups based on the treatment received: active surveillance (AS) or active treatment (AT). Age, gender, tuberous sclerosis syndrome, tumor size, contralateral kidney disease, renal function, year of diagnosis, and symptoms at presentation were assessed as potential predictive factors of active treatment using a logistic regression model in univariate and multivariate analyses.

Results

In total, 253 patients (mean age 52.3 ± 15.7 years; 70% women; 70.9% incidentally diagnosed) were included in the analysis. One hundred and nine (43%) received AS, whereas 144 (57%) were actively treated. For univariate analysis, age, tuberous sclerosis complex syndrome, tumor size, symptoms at presentation, and contralateral kidney disease were found to be predictors of AT. Only tumor size (p < 0.001) and the year of diagnosis (p < 0.001) remained significant for multivariable analyses. The likelihood of being managed with AS evolved over the study period and was 50% and 75% when diagnosed before and after 2010, respectively. With respect to size, 4-cm and 6-cm tumors had a probability of 50% and 75% of being treated with AS, respectively.

Conclusion

The present analysis from a high-volume institution provides evidence that the management of renal masses with typical radiological features of AML has markedly changed over the last three decades with a trend toward AS over AT. Tumor size and the year of diagnosis were significant factors for the treatment strategies.

Angiomyolipoma of the kidney-Clinicopathological analysis of 52 cases

The renal angiomyolipoma (AML) is a benign tumor characteristically composed of fat, smooth muscle tissue, and vessels. We collected AMLs from our nephrectomy database, reclassified them according to their histological appearance, recorded the demographic, clinical, and pathological parameters, and compared them with oncocytoma (RO) and renal cell carcinoma (RCC). Immunohistochemistry was ordered in 41 cases. In 2224 nephrectomies, we found 52 AMLs with a 53 mm median size. The mean age was 52.76. Forty-eight tumors were sporadic, while four were hereditary. The revision resulted in 31 classic, 13 leiomyoma-like, five lipoma-like, two epithelioid, and one AML with epithelial cysts. SMA was diffusely positive, except for the epithelioid type, while MelanA harbored stronger expression than HMB45. AML was more frequent in females and appeared ten and 7 years earlier than RO and RCC, respectively. The follow-up time was 7.42 years, and neither tumor-related death nor relapse occurred. AML is rare in nephrectomies and develops primarily in females in their 50s with an average size of 50-60 mm at the surgery. The histological appearance in order of frequency is classic, leiomyoma-like, lipoma-like, epithelioid, and cystic. The MelanA, HMB45, and SMA immunohistochemistry can support the light-microscopic findings.

Sporadic Renal Angiomyolipoma: Can We Adopt a Uniform Management Protocol?

Renal angiomyolipomas (AMLs), formerly known as PEComas (tumors showing perivascular epithelioid cell differentiation) are common benign renal masses composed of a varying ratio of fat, blood vessels, and smooth muscles. They are largely asymptomatic and diagnosed incidentally on imaging.

The adipose tissue content is the factor that gives AMLs their characteristic appearance on imaging and makes them easily identifiable. However, the fat-poor or fat-invisible varieties, which are difficult to differentiate radiologically from renal cell carcinomas (RCCs), present a diagnostic challenge. It is thus essential to establish the diagnosis and identify the atypical and hereditary cases as they require more intense surveillance and management due to their potential for malignant transformation.

Multiple management options are available, ranging from conservative approach to embolization and to the more radical option of nephrectomy. While the indications for intervention are relatively clear and aimed at a rather small cohort, the protocol for follow-up of the remainder of the cohort forming the majority of cases is not well established. The surveillance and discharge policies therefore vary between institutions and even between individual practitioners. We have reviewed the literature to establish an optimum management pathway focusing on the typical AMLs.

Monitoring and Managing Patients with Tuberous Sclerosis Complex: Current State of Knowledge

Tuberous sclerosis complex (TSC) is a rare genetic disease of autosomal dominant transmission that, in most cases, results from the presence of pathogenic variants of the TSC1 or TSC2 genes, encoding hamartin and tuberin, respectively. It is a multisystemic disease, affecting most frequently the brain, skin, kidney, and heart. The wide variety of possible clinical manifestations, given this multisystem dimension, makes the follow-up of patients with TSC an exercise of multidisciplinarity. In fact, these patients may require the intervention of various medical specialties, which thus have to combine their efforts to practice a medicine that is truly holistic. The past few years have witnessed a dramatic leap not only in the diagnosis and management of TSC patients, with standard monitoring recommendations, but also in the therapeutic field, with the use of mTORC1 inhibitors. In this article, we review the clinical manifestations associated with TSC, as well as the treatment and follow-up strategies that should be implemented, from a multidisciplinary perspective.

Spontaneous rupture of renal angiomyolipoma and its management: A case report

a) Introduction and Importance

Angiomyolipomas of kidney are benign lesions that are generally an incidental finding on imaging. Rupture of angiomyolipoma is rare and fatal complication that requires early intervention.

b) Case Presentation

A 38 year old male patient presented with symptoms of right flank pain for 2 days. On clinical examination patient looked anxious, pale with right flank tenderness, guarding and signs of shock.

c) Clinical findings and investigations

CT scan showed renal angiomyolipoma with aneurysm formation and bleed from the lesion. Blood profile revealed low hemoglobin.

d) Interventions and Outcome

Right nephrectomy performed along 6 cycles of cardiopulmonary reususcitaion done with stable post operatively vitals.

e) Conclusion

Early diagnosis of complication of angiomyolipoma requires thorough clinical examination and judicious use of imaging. Immediate embolization or surgery must be performed for better outcome and survival rate.

•

Angiomyolipoma is composed of fat, smooth muscle and blood vessels and presents among 0.3% of the population.

•

Renal angiomyolipoma are prone to aneurysm formation and bleed, however a nontraumatic spontaneous renal hemorrhage from a sporadic renal angiomyolipoma is a rare condition.

•

Mostly angiomyolipoma are asymptomatic and are diagnosed incidentally. CT scan is the diagnostic modality of choice.

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Patients with life-threatening hemorrhage require immediate intervention that includes embolization or surgery for better outcome and survival rate.

Prevalence of thoracoabdominal imaging findings in tuberous sclerosis complex

Background

Tuberous sclerosis complex (TSC) results in neurodevelopmental phenotypes, benign tumors, and cysts throughout the body. Recent studies show numerous rare findings in TSC. Guidelines suggest routine abdominal and chest imaging to monitor these thoracoabdominal findings, but imaging is not uniformly done across centers. Thus, the prevalence of many findings is unknown. To answer this, we categorized the clinical reads of 1398 thoracoabdominal scans from 649 patients of all ages in the Cincinnati Children’s Hospital TSC Repository Database.

Results

Typical TSC findings were present in many patients: kidney cysts (72%), kidney fat-containing angiomyolipomas (51%), kidney lipid-poor angiomyolipomas (27%), liver angiomyolipomas (19%), and lung nodules thought to represent multifocal micronodular pneumocyte hyperplasia (MMPH) (18%). While many features were more common in TSC2 patients, TSC1 patients had a higher prevalence of MMPH than TSC2 patients (24% versus 13%, p = 0.05). Many rare findings (e.g., lymphatic malformations and liver masses) are more common in TSC than in the general population. Additionally, most thoracoabdominal imaging findings increased with age except kidney cysts which decreased, with the 0–10 years age group having the highest percentage (69% 0–10 years, 49% 10–21 years, 48% 21 + years, p < 0.001). Finally, in our population, no patients had renal cell carcinoma found on abdominal imaging.

Conclusions

These results show that regular thoracoabdominal scans in TSC may show several findings that should not be ignored or, conversely, over-reacted to when found in patients with TSC. Female sex, TSC2 mutation, and age are risk factors for many thoracoabdominal findings. The data suggest novel interactions of genetic mutation with pulmonary nodules and age with renal cysts. Finally, in agreement with other works, these findings indicate that several rare thoracoabdominal imaging findings occur at higher rates in the TSC population than in the general population. This work supports obtaining detailed thoracoabdominal imaging in patients with TSC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02277-x.

Active Surveillance for Renal Angiomyolipoma Less Than 4 Centimeters: A Systematic Review of Cohort Studies

The aim of this review is to evaluate the current evidence regarding the best management in terms of active surveillance of angiomyolipoma (AML) cases less than 4 cm, particularly the optimal timing of active surveillance. In addition, we aimed to describe their initial size, clinical presentation, and growth rates. The present systematic review included prospective and retrospective studies that evaluated and followed up patients with AML through active surveillance. Studies were retrieved through an online bibliographic search of the Medline database via PubMed, SCOPUS, Web of Science, and Cochrane Library from their inception to January 2022. Seven studies were included in the present systematic review. Concerning the active surveillance protocol, only four studies describe the frequency of active surveillance and the utilized imaging modality. Some studies followed up lesions by ultrasound annually for two to five years, while other studies followed-up patients twice for the first year, then annually for a median follow-up period of 49 (9-89) months. The used modalities were ultrasound, CT, and magnetic resonance imaging (MRI). Notably, the incidence of spontaneous bleeding was consistent across the included studies (ranging from 2.3 - 3.1%), except for one study which showed an incidence rate of 15.3%. In terms of the need for active treatment, the rate of active treatment was slightly higher in some studies than the others. However, this variation could not be considered clinically relevant to favor one surveillance strategy over the other. We concluded that active surveillance is the first line of management in all small asymptomatic ALMs. ALMs less than 2 cm do not require active surveillance. The current published literature suggested that active surveillance for two years may provide the same benefits as a five-year surveillance strategy, with fewer radiation hazards and less socioeconomic burden.

OUP accepted manuscript

Background

Everolimus is a potential alternative to embolization and nephrectomy for managing tuberous sclerosis complex (TSC)-associated renal angiomyolipoma (AML). In 2016, National Health Service England approved its use through regional centres for renal AML ≥30 mm showing interval growth. Evidence of lesion stabilization or reduction after 6 months is mandated for continuation of long-term treatment.

Methods

From November 2016 to June 2021, all potentially eligible adult TSC patients with AML across Yorkshire and Humber were referred for assessment and monitoring. Eligible patients underwent baseline renal magnetic resonance imaging (MRI) assessment and a follow-up MRI scan after 6 months on everolimus. Dose titration was guided by trough levels and lesion responsiveness using a new 3D MRI volumetric protocol.

Results

Of 28 patients commencing treatment, 19 tolerated everolimus for >3 months. Overall, 11 patients (40%) discontinued treatment, mostly due to recurrent infections (42%) and allergic reactions (25%). Sixty-eight percent required dose adjustments from the initiating dose (10 mg) due to sub-optimal trough levels (38%), minimal AML response (15%) or adverse events (47%). 3D volumetric assessment confirmed a reduction in AML volume of a pre-selected index lesion in all treatment-naïve cases (n = 14), showing superiority over 2D measurements of lesion diameter.

Conclusion

In this cohort, everolimus promoted AML regression in all patients who tolerated the drug for >6 months with stabilization observed over 3 years. Trough levels enabled individual dose titration to maximize responsiveness and minimize side effects. The use of 3D MRI assessment of lesion volume was superior to 2D measurements of lesion diameter in monitoring treatment response.

Bilateral renal angiomyolipomas in tuberous sclerosis

Background

Tuberous sclerosis complex (TSC) is a rare genetic disorder characterized by benign hamartomas in multiple organs of the body. Renal angiomyolipomas (AML) are commonly associated with TSC. They are mostly asymptomatic. But large and rapidly growing AMLs with the presence of an aneurysm cause symptoms and pose a life-threatening risk for hemorrhage.

Case presentation

Our patient is a 25-year-old female who presented to us as an undiagnosed case of tuberous sclerosis having a large abdominal mass. She fulfilled the clinical criteria required for the diagnosis of TSC. The CT scan revealed an 18 × 13 × 33 cm fat-containing lesion in the right kidney with an adjacent aneurysm measuring around 16 cm in diameter. Due to the large size of the AML and associated aneurysm, surgical exploration was mandated. On the contralateral kidney, multiple contrast-enhancing soft-tissue densities were present that appeared suspicious on radiology. So a percutaneous biopsy of those lesions was done. Fortunately, it had the same histopathology as an Angiomyolipoma. Nephrectomy of the right-sided kidney with AML has been done. The left-sided lesions that are less than 2 cm and asymptomatic are kept on close surveillance. Any change in size will prompt therapy with mTOR inhibitors.

Conclusion

When dealing with bilateral renal AML, it is important to adopt a conservative approach. When intervention is indicated, the least invasive strategy should be sought and enacted. Radical surgery should be the last resort.

Updated International Tuberous Sclerosis Complex Diagnostic Criteria and Surveillance and Management Recommendations

BACKGROUND

Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disease affecting multiple body systems with wide variability in presentation. In 2013, Pediatric Neurology published articles outlining updated diagnostic criteria and recommendations for surveillance and management of disease manifestations. Advances in knowledge and approvals of new therapies necessitated a revision of those criteria and recommendations.

METHODS

Chairs and working group cochairs from the 2012 International TSC Consensus Group were invited to meet face-to-face over two days at the 2018 World TSC Conference on July 25 and 26 in Dallas, TX, USA. Before the meeting, working group cochairs worked with group members via e-mail and telephone to (1) review TSC literature since the 2013 publication, (2) confirm or amend prior recommendations, and (3) provide new recommendations as required.

RESULTS

Only two changes were made to clinical diagnostic criteria reported in 2013: "multiple cortical tubers and/or radial migration lines" replaced the more general term "cortical dysplasias," and sclerotic bone lesions were reinstated as a minor criterion. Genetic diagnostic criteria were reaffirmed, including highlighting recent findings that some individuals with TSC are genetically mosaic for variants in TSC1 or TSC2. Changes to surveillance and management criteria largely reflected increased emphasis on early screening for electroencephalographic abnormalities, enhanced surveillance and management of TSC-associated neuropsychiatric disorders, and new medication approvals.

CONCLUSIONS

Updated TSC diagnostic criteria and surveillance and management recommendations presented here should provide an improved framework for optimal care of those living with TSC and their families.

Bilateral Renal Replacement Lipomatosis: A Case Report on Rare Complication of Obstructive Uropathy

Renal replacement lipomatosis (RRL) is an uncommon complication, leading to the fatty replacement of the renal parenchyma. Various etiologies have been described for this long-term infirmity, but obstructive uropathy is one paramount cause. Previously described reports have documented unilateral disease in the majority, but we are narrating a case of bilateral RRL, which is very scarce in the literature. A 57-year-old man, who was a known case of obstructive uropathy, presented to us with the symptoms of urinary tract infection. In imaging evaluation, the patient was found to have bilateral RRL.

Sequential everolimus for angiomyolipoma associated with tuberous sclerosis complex: a prospective cohort study

Background

To evaluate the efficacy, safety and health economics of sequential everolimus in treating angiomyolipoma (AML) associated with tuberous sclerosis complex (TSC).

Methods

In this prospective cohort study, patients met the inclusion criteria received standard or sequential treatment according to their willingness. All patients received an initial dose of everolimus (10 mg oral, once a day) for 3 months. The standard treatment group maintained 10 mg QD for 12 months, while the sequential treatment group reduced the dose to 5 mg QD from the 4th month. The efficacy, serum everolimus concentration and safety were evaluated at 1, 3, 6, 9 and 12 months after treatment. The primary efficacy endpoint was the proportion of patients with confirmed angiomyolipoma response of at least a 50% reduction in the total volume of target AML relative to baseline.

Results

Between June 1, 2016 and June 1, 2017, a total of 53 patients were included. Twenty-three patients received standard treatment, 30 patients received sequential treatment. At 1, 3, 6, 9 and 12 months after treatment, the proportion of patients whose total target tumor volume decreased by ≥ 50% from baseline was 39.1% versus 36.7%, 43.5% versus 56.7%, 47.8% versus 50%, 47.8% versus 60% and 47.8% versus 23.3% respectively (P > 0.05 for all). The overall response rate of skin lesions in the two groups was 40.4%, and the response rates of skin lesions at different times were similar for two groups (P > 0.05 for all). Major adverse effects (AEs) included mouth ulceration, hypertriglyceridemia, hypercholesterolemia, menstrual disorders. There was no significant difference between the two groups in the incidence of AEs at 3 months after treatment. The incidence of overall and grade 3/4 AEs at 12 months after treatment were significantly lower in the sequential treatment group. The average direct cost of the two groups in 12 months was $15,466 and $11,120, respectively.

Conclusions

Compared to standard treatment, sequential treatment was equally effective, with a lower incidence of adverse events and a lower direct cost, suggesting that it may be an alternative treatment for AML associated with TSC.

Natural growth pattern of sporadic renal angiomyolipoma

BACKGROUND

Surveillance of sporadic renal angiomyolipomas is a growing issue for physicians and radiologists. Current treatment recommendations favor active surveillance. However, the evidence underlying these is based on small case series, which also typically include angiomyolipomas associated with tuberous sclerosis.

PURPOSE

To evaluate the natural growth pattern of sporadic renal angiomyolipomas in patients without tuberous sclerosis.

MATERIAL AND METHODS

A retrospective review was performed in three separate tertiary referral centers. A keyword search of each institutions PACS history was performed. Inclusion criteria were angiomyolipomas > 1 cm in size, three years of follow-up, and lesions requiring treatment before reaching three years of follow-up. Exclusion criteria included a diagnosis of tuberous sclerosis, pregnancy, prior treatment with embolization without any prior imaging, and lesions which were treated on presentation. Growth of the angiomyolipomas was evaluated on the basis of maximum dimension on initial and follow-up images.

RESULTS

Sixty-three patients were identified in total, with 64 lesions eligible for inclusion. The majority of patients were women (55/63). The mean age at which the angiomyolipomas discovered was 56.4 years. Mean total growth was 0.085 mm and mean follow-up was 65.5 months. At initial measurement, the mean maximum dimension of the lesions in our cohort was 2.08 cm. After follow-up, this was 2.16 cm. The average rate of growth was 0.015 cm per year.

CONCLUSION

Sporadic angiomyolipomas exhibit minimal, if any, natural growth. Current surveillance strategies could be relaxed.

Diagnostic value of ultrasound in the spontaneous rupture of renal angiomyolipoma during pregnancy: A case report

BACKGROUND

Spontaneous rupture and hemorrhage of renal angiomyolipoma (RAML) is a life-threatening clinical emergency. When it occurs during pregnancy, it is compared to a “bomb explosion,” which makes the diagnosis and treatment more challenging. An ultrasound examination is a quick and safe examination with the benefit of no radiation exposure, which is always preferred for pregnant women. Currently, cases of spontaneous rupture and hemorrhage of RAML during pregnancy are rare, as is the diagnostic value and characteristics of ultrasound. The lack of understanding of the condition among ultrasound doctors makes it prone to misdiagnosis. In this study, we present the case of a pregnant woman who was preliminarily diagnosed with spontaneous rupture and hemorrhage of the left RAML using ultrasound and discuss the ultrasound characteristics.

CASE SUMMARY

A 38-year-old woman in her 19^th wk of pregnancy (G2P1) was referred to our clinic for a sudden, persistent pain on the left side of the waist. She had not undergone any previous related abdominal examination. Ultrasound of the urinary system revealed a giant nonhomogenous lump in the left kidney area. The diagnosis was considered spontaneous rupture and hemorrhage of the left RAML in pregnancy via ultrasound. Her left-side waist pain continued to be intense. Subsequently, she underwent computed tomography, which led to the same diagnosis. Based on many factors, the patient underwent left nephrectomy after the induction of labor. The pathological result was the rupture and hemorrhage of a vascular leiomyoma lipoma.

CONCLUSION

Ultrasound examination plays an important role in the diagnosis of the spontaneous rupture and hemorrhage of RAML during pregnancy.

An Incidental Diagnosis of Microscopic Renal Angiomyolipoma Completely Excised on Renal Biopsy: A Case Report

Patient: Female, 44-year-old

Final Diagnosis: Angiomyolipoma

Symptoms: Asymptomatic proteinuria

Medication:—

Clinical Procedure: —

Specialty: Pathology

Germline mutation of TSC1 or TSC2 gene in Chinese patients with bilateral renal angiomyolipomas and mutation spectrum of Chinese TSC patients

The germline mutation of the TSC1/2 gene in bilateral renal angiomyolipomas is unclear. Meanwhile, the mutation spectrum of Chinese TSC patients has not been revealed. We recruited 78 patients diagnosed with bilateral renal AMLs. High-throughput sequencing was used to detect any variants in TSC1/2 genes. The results showed that 28.6% of patients diagnosed before 45 were with positive results of TSC1/2 test. The rate decreased to 14.3% for those with onset age over 45. For the 315 previously reported Chinese patients, TSC1 patients were more likely to be affected by nonsense mutations (51.1% vs. 20.7%, p<0.001) and had a significantly higher rate of family history than TSC2 patients (37.8% vs. 19.6%, p=0.0067). Moreover, exon8, 15, and 18 were the hotspot mutation regions for TSC1, and exon 29, 33 and 40 were the most common mutation regions for TSC2. Besides, Chinese TSC patients carried more TSC2 alterations (85.7% vs.76.2%, p<0.001), and were more likely to have a family history than those from TOSCA (22.2% vs. 13.9%, p<0.001). In conclusion, patients affected by bilateral renal AMLs should receive genetic testing of TSC ½ genes and Chinese TSC patients have relatively hotspot mutation regions, which are helpful to genetic counseling and clinical decision making.

Can subcentimetre ultrasound detected angiomyolipomas be safely disregarded?

AIM

To optimise follow-up by dismissing lesions on baseline ultrasound (US) if renal lesions conform to US criteria of an angiomyolipoma (AML).

METHOD AND MATERIALS

The present study was a 10-year retrospective review of patients who were found to have incidental hyperechoic renal lesions on US to ascertain the outcome from subsequent imaging, clinical encounters, and cancer registrations. Exclusions included renal calculi, tuberous sclerosis, Von-Hippel-Lindau, or a known cancer.

RESULTS

After excluding 39 patients, 1,493 patients were identified. One hundred and sixty had more than one lesion with 87 patients having bilateral lesions. Regardless of indication, 889 patients had subsequent imaging within 5 years (59.5%). The average size of all AMLs was 13.2 mm. In the group with lesions that were <10 mm (807), 438 had imaging follow-up with an average follow-up time of 1.5 years. Mean lesion size in this group was 7 mm, with an average increase of <0.5 mm on follow-up. No lesions were found to be malignant on subsequent imaging nor did any of these patients have a subsequent renal cancer diagnosis registered at local multidisciplinary team meetings.

CONCLUSION

No incidental subcentimetre hyperechoic renal lesion with imaging characteristics of an AML demonstrated significant growth or developed into a malignancy on follow-up.

Oxidant and antioxidant levels and DNA damage in tuberous sclerosis

OBJECTIVE

The pathogenesis of inherited diseases is thought to involve oxidative stress and the associated DNA damage, which are also implicated in many other conditions including cancer. Tuberous sclerosis is a genetic disease with autosomal dominant inheritance pattern that is characterized by the development of hamartomas in multiple organ systems. Oxidative stress and the related DNA damage are also likely to play a significant role in the pathogenesis of this condition. Thus, our study aimed to assess total oxidant-antioxidant level, oxidative stress index and DNA damage in patients diagnosed with tuberous sclerosis.

METHODS

The study included 30 patients with tuberous sclerosis between the ages of 0 and 16 years. The control group consisted of 29 age-matched healthy children. Blood samples obtained from each subject were centrifuged to separate the sera. The Total Antioxidant Status (TAS) and Total Oxidant Status (TOS) were measured in serum samples with a Thermo Scientific Multiscan plate reader (FC, 2011-06, USA) at wavelengths of 240 nm and 520 nm, respectively. The measured TAS and TOS values were used to calculate the Oxidative Stress Index (OSI). In addition, the Comet Assay Method was used to determine DNA damage in the samples. Data were analyzed using SPSS software.

RESULTS

Patients with tuberous sclerosis complex (TSC) and controls were compared with respect to TAS, TOS, and OSI. TAS was significantly lower (p < 0.01), while TOS and OSI were significantly higher (p < 0.01, for both) in patients as compared to controls. In addition, patients had significantly higher DNA damage as shown by the Comet Assay (p < 0.01).

CONCLUSIONS

Increased oxidative stress and DNA damage may contribute to the pathogenesis of tuberous sclerosis.

Tuberous sclerosis complex: new insights into clinical and therapeutic approach

Tuberous sclerosis complex (TSC) is a complex disease with many different clinical manifestations. Despite the common opinion that TSC is a rare condition, with a mean incidence of 1/6000 live births and a prevalence of 1/20,000, it is increasingly evident that in reality this is not true. Its clinical sequelae span a range of multiple organ systems, in particular the central nervous system, kidneys, skin and lungs. The management of TSC patients is heavily burdensome in terms of time and healthcare costs both for the families and for the healthcare system. Management options include conservative approaches, surgery, pharmacotherapy with mammalian target of rapamycin inhibitors and recently proposed options such as therapy with anti-EGFR antibody and ultrasound-guided percutaneous microwaves. So far, however, no systematically accepted strategy has been found that is both clinically and economically efficient. Thus, decisions are tailored to patients' characteristics, resource availability and clinical and technical expertise of each single center. This paper reviews the pathophysiology and the clinical (diagnostic-therapeutic) management of TSC.

Embolization of hemorrhagic renal angiomyolipoma complicated by arteriovenous shunting: A case report

Arteriovenous shunting associated with angiomyolipoma is an unusual entity, which carries important implications to embolization approach. We present a distinctive case involving a 41-year-old woman who presented with retroperitoneal hemorrhage relating to renal angiomyolipoma. During angiography for urgent embolization, a complex vascular supply with arteriovenous shunting was encountered. Superselective embolization using alcohol or small particles is the standard approach to definitive treatment of symptomatic angiomyolipoma; however; their use is precluded in the setting of arteriovenous shunt hemodynamics. In this case, a 2-step approach was employed by which the initial hemorrhage was treated with proximal embolization using large gelatin foam and metallic coils. This resulted in decreased flow through the arteriovenous shunt, allowing the use high viscosity ethylene vinyl alcohol copolymer dissolved in dimethyl sulfoxide for definitive treatment.

Thoracoabdominal imaging of tuberous sclerosis

Imaging of tuberous sclerosis complex has rapidly evolved over the last decade in association with increased understanding of the disease process and new treatment modalities. Tuberous sclerosis complex is best known for the neurological symptoms and the associated neuroimaging findings, and children with tuberous sclerosis complex require active surveillance of associated abnormalities in the chest, abdomen and pelvis. Common findings that require regular imaging surveillance are angiomyolipomas in the kidneys and lymphangioleiomyomatosis in the chest. However multiple rarer associations have been attributed to tuberous sclerosis complex and should be considered by radiologists reviewing any imaging in these children. In this review the authors discuss the spectrum of imaging findings in people with tuberous sclerosis complex, focusing on MR imaging findings in the chest, abdomen and pelvis.

Burden of renal angiomyolipomas associated with tuberous sclerosis complex: results of a patient and caregiver survey

Background

Tuberous sclerosis complex (TSC) is a rare genetic disorder characterized by benign tumors in multiple organs, including non-cancerous kidney lesions known as renal angiomyolipomas. This study’s objective is to describe the age-stratified morbidity, treatment patterns, and health-related quality of life of TSC patients with renal angiomyolipomas in the United States. A cross-sectional, anonymous web-based survey was conducted with a convenience sample of TSC patients and caregivers identified through a patient advocacy organization.

Results

Out of the total sample of 676, 182 respondents reported having kidney complications with 33% of the pediatric group and 25% of the adult group with TSC reporting them. Of those with kidney complications, 110 (60%) reported a diagnosis of renal angiomyolipomas, of which 79 (72%) were adult patients and 31 (28%) were pediatric age patients. Eighty-four percent of the pediatric group and 76% of the adult group reported lesions on both kidneys. Of the patients experiencing involvement of only one kidney, 60% of the pediatric group and 21% of the adult group reported having multiple tumors within the affected kidney. Almost all of the sample (99%) reported seeing a physician and having a procedure or test for TSC in the past year. Less than half the respondents (44%) reported being hospitalized in the past year. Thirty-nine percent reported an emergency room visit as well. Compared to scores for patients with kidney disease, the angiomyolipoma adult patients reported significantly lower Mental Component Summary scores on the SF-12.

Conclusions

Renal angiomyolipomas burden leads to frequent healthcare resource use including hospitalization, invasive treatments, and surgical procedures, which result in an impaired mental health related quality of life.

Benign Neoplasm of Kidney: Angiomyolipoma

Angiomyolipoma is one of the renal benign neoplasms. The most of the angiomyolipomas are asymptomatic and found incidentally with ultrasound. They are more prevalent in patients with tuberous sclerosis. It is very important to make differential diagnosis from other renal neoplasm such as renal cell carcinoma. Growth rate is higher among pregnant women suggest that the hormones may play a role in the stimulation of angiomyolipoma. The most common serious presentation is rupture and hemorrhage, and sometimes it can lead to shock. Adequate diagnosis, treatment, and follow-up are very important in the face of renal angiomyolipoma.

Postembolization Intratumoral Chronic Bleeding, without the Classic CT Feature of Active Extravasation, in Tuberous Sclerosis Complex-Related Renal Angiomyolipoma: Two Case Reports

Two patients with tuberous sclerosis complex each had multiple bilateral renal angiomyolipomas. After undergoing embolization for a ruptured angiomyolipoma, patient 1 experienced long-lasting abdominal fullness; contrast-enhanced computed tomography (CECT) revealed a large chronic hematoma without contrast extravasation. Patient 2 underwent embolization for the largest right renal angiomyolipoma which contained a chronic hematoma. 2 weeks later, the symptom of abdominal fullness presented, and CECT revealed that the preexisting hematoma had enlarged without contrast extravasation. In both cases, a second embolization of the angiomyolipomas resulted in shrinking of the intratumoral hematomas and alleviation of the associated symptoms. Therefore, chronic postembolization intratumoral bleeding from renal angiomyolipoma may present as a persistently large or growing hematoma with an associated symptom of abdominal fullness but without the typical CECT feature of active extravasation.

Renal Angiomyolipoma: The Good, the Bad, and the Ugly

Angiomyolipomas (AMLs) are the most common benign renal tumours. Most of these neoplasms are found incidentally on imaging. However, symptomatic presentation does exist. Renal AMLs are typically composed of smooth muscle, blood vessels, and adipose tissue. Because of the abundant fat tissue, they give a characteristic appearance on imaging and are therefore easily diagnosed. However, sometimes they contain too little fat to be detected. This increases the difficulty in differentiating them from renal cell carcinoma (RCC). Management of AML is based on clinical presentation and should be individualized for every patient. Treatment modalities range from active surveillance to more invasive approaches.

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.

Laparoscopic partial nephrectomy with prior superselective embolisation as treatment for giant renal angiomyolipoma

OBJECTIVE

Cases of giant renal angiomyolipoma (>9cm) are a therapeutic challenge due to their low frequency and large size. The treatment objective for patients with renal angiomyolipoma should be complete tumour extirpation, with a nephron-sparing surgical technique, without complications and using a minimally invasive approach.

MATERIAL AND METHODS

We present 3 cases of giant angiomyolipoma (10 12 and 14cm) treated with a combined approach: superselective embolisation and subsequent laparoscopic partial nephrectomy, in 3 separate hospitals.

RESULTS

None of the cases required conversion to open surgery. One of the 3 patients underwent arterial clamping, and none of the patients had complications.

CONCLUSIONS

The combined approach provides a procedure with the criteria of minimal invasiveness, nephron sparing, little bleeding and reduced warm ischaemia time.