Renal angiomyolipomata

Giant Retinal Astrocytoma: A Case Report of an Uncommon Presentation of Tuberous Sclerosis in a Young Female

Tuberous sclerosis (TS) is a rare multisystem autosomal dominant genetic disorder with characteristic pathognomonic genetic mutations involving the TSC (tuberous sclerosis complex) group of genes. Ocular signs are fairly common and include an achromic patch and retinal astrocytic hamartomas, which usually have a maximum size of between 0.5 and 5 mm. The incidence of tuberous sclerosis is estimated to be 1 in 5000-10,000 individuals, with both familial and sporadic cases reported. The diagnostic criteria for tuberous sclerosis include the presence of major and/or minor clinical features as well as genetic mutations. We present the case of a 15-year-old girl, presented with a history of seizures and blurred vision. Physical examination revealed angiofibroma on the face. Further evaluation, including contrast-enhanced MRI of the brain and ophthalmological consultation, led to the diagnosis of tuberous sclerosis. Additional imaging studies confirmed the presence of subependymal giant cell astrocytoma, retinal astrocytoma, lymphangioleiomyomatosis in the lungs, and renal angiomyolipoma. This case highlights the importance of considering tuberous sclerosis in patients presenting with seizures and ocular symptoms. This case sheds light on early diagnosis and appropriate management which are crucial in preventing complications and improving patient outcomes.

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.

Autopsy findings of fatal retroperitoneal hemorrhage after traumatic rupture of bilateral renal angiomyolipoma

The present work reports the autopsy findings of a unique case characterized by fatal retroperitoneal hemorrhage following the traumatic rupture of bilateral renal angiomyolipomas. Renal angiomyolipomas are generally benign tumors with an unpredictable clinical course, ranging from asymptomatic to sudden rupture and hemorrhagic shock. They may be associated with genetic disorders such as tuberous sclerosis complex. The case under investigation is unprecedented in the medical literature due to its bilateral nature and fatal outcome. Autopsy analysis revealed an extensive retroperitoneal hemorrhage originating from bilateral ruptured tumors. Microscopic examination found features consistent with bilateral renal angiomyolipoma. Circumstantial information identified a traffic accident before the death, considering it as the cause of the tumors' traumatic rupture. In this case, due to the severity of the situation, immediate medical measures-such as fluid resuscitation, coagulopathy correction, and surgical treatment, which are usually lifesaving-could not be performed. This led to the patient being declared dead at the scene of the crash.

Effectiveness and safety of everolimus treatment in patients with tuberous sclerosis complex in real-world clinical practice

BACKGROUND

The randomised double-blinded placebo-controlled EXIST-1-3 studies have showed everolimus effective with adverse effects reported as acceptable in treatment of symptoms in patients with tuberous sclerosis complex (TSC), although evidence of outcomes in clinical practice remains limited. This study aimed to investigate, in clinical practice, the effectiveness and safety of everolimus for epilepsy, renal angiomyolipoma (rAML), and subependymal giant cell astrocytoma (SEGA) in patients with TSC.

RESULTS

The study included 64 patients with TSC (median age: 19, range 0.9-54 years) receiving everolimus treatment (Norway: n = 35; Denmark: n = 29). Among 45 patients with epilepsy, 14 (31%) were responders experiencing ≥ 50% reduction in seizure frequency in the last 3 months of treatment compared with the last 3 months before treatment. Nineteen (42%) patients changed their anti-seizure medications (ASMs). Responders were more common among patients < 18 years (46%) than among patients ≥ 18 years (14%, p = 0.03). In 29 patients with rAML, everolimus reduced (≥ 30% decrease) and stabilized (< 20% increase, ≤ 30% decrease) longest diameter of rAML in 38% and 59%, respectively, after a mean treatment duration of 37 months. SEGA volume was reduced in three patients by 71%, 43%, and 48% after 39, 34, and 82 months. Adverse effects were reported in 61 of 64 patients (95%) after a median treatment duration of 31 months (range 0-106), with oral ulceration/stomatitis (63%) and upper respiratory tract infections (38%) being the most common. The most common laboratory abnormalities were increased cholesterol (41%), anaemia (30%), and leucopoenia (25%). Grade 3-4 adverse effects were reported in 36% of cases, and life-threatening conditions were reported in two patients. Nine patients discontinued everolimus treatment.

CONCLUSIONS

Seizure reduction in this study sample was consistent with results from EXIST, but might be lower than expected, given that changes in concomitant ASMs are part of clinical practice. Seizure reduction was associated with younger age. As with EXIST, everolimus reduced or stabilised rAML size in most patients. SEGA volume was reduced in all three patients. Close follow-up is needed for this group, especially for children and patients who may not be able to report adverse effects.

Renal angiomyolipoma: Beyond size criteria for predicting rupture

INTRODUCTION

Renal angiomyolipomas (AMLs) are vascular tumours that while histologically benign, carry a risk of rupture and potentially life-threatening haemorrhage. Selective arterial embolisation (SAE) has been demonstrated as effective treatment; however, given most tumours are asymptomatic, the challenge facing the radiologist is selection of which AML should undergo treatment. This study considers presence and size of intratumoural aneurysm, to advance the readers treatment decision-making beyond historical size criteria.

METHODS

Retrospective cohort analysis of all SAE-treated AML at a quaternary-level institution in the last 10 years was completed independently by two radiologists. Computerised tomography (CT) and angiographic imaging were reviewed to evaluate tumour size, presence of intratumoural aneurysm and aneurysm size. Univariant and multivariant statistical analyses were used to identify predictors of spontaneous rupture and haemorrhage.

RESULTS

Twenty-seven renal AML underwent SAE. Five tumours had presented with haemorrhage. Twenty-two were asymptomatic or without CT/angiographic detectable haemorrhage. There was no statistically significant size difference between ruptured (mean 7.8 cm, range 6.1-12.0 cm) and unruptured AML (7.5 cm, 3.3-21.7 cm) in the study population. Eighty percent of ruptured AML and 27% of unruptured AML contained at least one intratumoural aneurysm (P-value < 0.05). Mean aneurysm size in ruptured AMLs was 5.4 mm, versus 4.6 mm among unruptured AML (P-value > 0.05).

CONCLUSION

The presence of intratumoural aneurysm is a useful predictor for AMLs that are at risk of spontaneous rupture and haemorrhage. Intratumoural aneurysm should therefore be considered when selecting patients to undergo SAE.

Molecular diagnosis of tuberous sclerosis complex in fetuses and infants: an institutional case series

OBJECTIVE

We describe the clinical and genetic characteristics of fetuses and infants diagnosed with tuberous sclerosis complex (TSC) in our centre, prenatally or neonatally, for a better understanding of the benefits of early screening.

METHODS

In this retrospective study, we analysed the data on one fetus and nine infants with a definitive TSC diagnosis by genetic criteria (five patients carrying TSC1 variants and 5 patients carrying TSC2 variants). We explored the differences between phenotypes of patients carrying TSC1 and TSC2 pathogenic variants.

RESULTS

The most common initial presenting features of TSC were cardiac rhabdomyomas (CRs) that were observed in nine out of ten patients. The most common postnatal features, besides CR, were presented with subependymal nodules-in five patients, and hypomelanotic macules-in four patients. In total, 10 variants causing TSC were detected in this study, including 5 novel variants. We demonstrated that patients with TSC2 variants had earlier onset and more severe clinical manifestations compared with patients carrying TSC1 variants.

CONCLUSION

Early diagnosis of TSC improves genetic counselling and perinatal management.

Safety, Efficacy and Mid-Term Outcome for Transarterial Embolization (TAE) of Renal Angiomyolipoma (AML) Using Ethylene Vinyl Alcohol Copolymer Liquid Embolic Agent (EVOH)

Transarterial embolization (TAE) of renal angiomyolipoma (AML) is effective in treating and preventing hemorrhage. We report our experience using EVOH with a single-center retrospective study of all AML embolized with EVOH between June 2013 and March 2022 at the Montpellier University Hospital. A total of 29 embolizations were carried out in 24 consecutive patients (mean age: 53.86 years; 21 women and 3 men) with 25 AMLs for severe bleeding, symptomatic AML, tumor size > 4 cm, or presence of aneurysm(s) > 5 mm. Data collected included imaging and clinical outcomes, tuberous sclerosis complex status, change in AML volume, rebleeding, renal function, volume and concentration of EVOH used, and complications. Out of 29 embolizations performed for 25 AMLs, four were performed in an emergency. Technical success was achieved for 24/25 AMLs. Mean AML volume reduction was 53.59% after a mean follow-up time of 446 days using MRI or CT scan. Aneurysms on angiogram and the symptomatological nature of AML, as well as secondary TAE and multiple arterial pedicles, were statistically associated (p < 0.05). Two patients (8%) underwent nephrectomy after TAE. Four patients had a second embolization. Minor and major complication rates were 12% and 8%, respectively. Neither rebleeding nor renal function impairment was noticed. TAE of AML using EVOH is, thus, highly effective and safe.

Incidental finding of tuberous sclerosis complex in a woman with hematuria: A case report of renal angiomyolipoma and review of the literature

Tuberous sclerosis complex (TSC) is a rare genetic multisystem disorder that was first described by Von Recklinghausen. We describe a case of a female, who initially presented with hematuria and was later found to have multiple manifestations of the disease. The report emphasizes the value of investigations on suspected cases.

Progress in Tuberous Sclerosis Complex Renal Disease

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder that affects both fetal development and postnatal tissue growth, resulting in altered brain structures and a tumor predisposition syndrome. Although every organ system is affected by the disease, kidney involvement is a leading cause of death in adults with TSC. Over the past decade, significant progress has been made in understanding the renal disease. This review focuses on the cystic and solid renal lesions in TSC, including their pathobiology and treatment.

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.

Ruptured angiomyolipoma, a novel entity for emergency physicians in the differential diagnosis of haemorrhagic shock in a female patient of reproductive age

A woman in her 30s presented to the emergency department with acute onset, progressively worsening left-sided abdominal pain after exercise. She was found to be hypotensive and diaphoretic, with free intraperitoneal fluid detected on bedside point-of-care ultrasound. Resuscitation was initiated, a presumptive diagnosis of ruptured ectopic pregnancy was made, and obstetrics and gynaecology were consulted. Point-of-care urine pregnancy testing, however, was negative, and subsequent CT angiography of the patient’s abdomen revealed an angiomyolipoma (AML) with active haemorrhage. Ultimately, embolisation was performed in the interventional radiology suite, with improvement of patient haemodynamics. Ruptured AML is a rare, life-threatening condition that needs to be included in the differential diagnosis of haemorrhagic shock in female patients of reproductive age presenting to the emergency department.

A Multi-Centric Study Assessing Safety and Efficacy of Everolimus in Adult Chinese Patients With Tuberous Sclerosis Complex Associated Renal Angiomyolipomas

Background

Everolimus has been approved in China for adult patients with TSC-AML (tuberous sclerosis associated renal angiomyolipomas) not requiring immediate surgery and has been previously shown to be an effective treatment option for TSC-AML in the Chinese population

Methods

This is an open label, single arm, multi-center Phase IV post-approval commitment study to further assess the safety and efficacy of everolimus in patients with TSC-AML who do not require immediate surgical intervention. The primary outcome was to evaluate the safety of everolimus while the secondary outcome was to evaluate AML response.

Results

Treatment with everolimus was associated with a clinically meaningful best overall AML response rate of 70% (95% CI: 53.5, 83.4). Of the 38 evaluable patients, 37 (97%) patients experienced a reduction in the sum of volumes of target angiomyolipoma lesions relative to baseline. At Week 12 (n=38), the median percentage change in sum of target AML volume was −56.60%, which further changed by -59.96% at Week 24 (n=38), and by −64.41% at Week 48 (n=22). Throughout the study, renal function remained relatively stable. Patients with TSC associated lymphangiomyomatosis (LAM) (N=13) demonstrated a lower than expected rate of decline in pulmonary function tests (PFTs). Everolimus was generally well tolerated with no significant safety findings in Chinese patients. Most of the adverse events were of grade 1-2, and manageable with appropriate dose adjustments and supportive therapies. There were no treatment discontinuation due to AE and no treatment death was reported.

Conclusions

Based on the efficacy and safety data presented in this study, the overall clinical benefit/risk assessment further supports the use of everolimus as a viable treatment option for Chinese patients with TSC-AML.

Perfect match: mTOR inhibitors and tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is an autosomal dominant syndrome that presents with diverse and complex clinical features and involves multiple human systems. TSC-related neurological abnormalities and organ dysfunction greatly affect the quality of life and can even result in death in patients with TSC. It is widely accepted that most TSC-related clinical manifestations are associated with hyperactivation of the mammalian target of rapamycin (mTOR) pathway caused by loss‑of‑function mutations in TSC1 or TSC2. Remarkable progress in basic and translational research has led to encouraging clinical advances. Although mTOR inhibitors (rapamycin/everolimus) demonstrate great potential in TSC management, two major concerns hamper their generalized application. One is the frequent manifestation of adverse events, such as stomatitis, infections, and menstrual disorders; and the other is the poor response in certain patients. Thus, indicators are required to effectively predict the efficacy of mTOR inhibitors. Herein, we have summarized the current utilization of mTOR inhibitors in the treatment of TSC and focused on their efficacy and safety, in an attempt to provide a reference to guide the treatment of TSC.

Hyperactivation of mammalian target of rapamycin (mTOR) is essential in the pathogenesis of tuberous sclerosis complex (TSC) and can serve as a therapeutic target.

mTOR inhibitors have shown considerable success in multiple clinical trials for the treatment of TSC, including neurological, pulmonary, cardiac, renal, and cutaneous phenotypes.

mTOR inhibitors are associated with adverse events, which should be considered during the management of TSC.

Indicators to predict mTOR inhibitor efficacy are required to select patients who are likely to benefit from such therapy.

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.

Racial differences in the dermatological manifestations of tuberous sclerosis complex and the potential effects on diagnosis and care

Background

Tuberous sclerosis complex (TSC) is an autosomal dominant neurocutaneous disorder of non-malignant tumor growths throughout major organ systems and neurological, neuropsychiatric, renal, and pulmonary co-morbidities. Skin manifestations are readily visible, often develop early in life, and are major features that contribute to TSC diagnosis. Medical photographs of such manifestations are commonly shown as examples from White individuals creating a potential barrier to accurately identifying these features in darker skinned individuals.

Objectives

The aim of this report is to raise awareness of dermatological manifestations associated with TSC, compare their appearance by race, and consider how recognition of these features could impact diagnosis and treatment of TSC.

Design and Methods

We conducted a retrospective chart review at the TSC Center of Excellence (TSCOE) at the Kennedy Krieger Institute, which included all patients in the center from 2009 (inception) through the end of the calendar year 2015 and analyzed data from the TSC Alliance Natural History Database (NHD).

Results

Among TSCOE patients, 50% of Black patients were diagnosed before the age of 1 year, compared with 70% of White patients. NHD data corroborated this trend showing a significant difference with only 38% of Blacks as compared with 50% of Whites were diagnosed at age ⩽1 year. A significant difference was observed where White participants had higher odds of having received genetic testing in both data sets. While no differences in the total number of TSC features was observed in either data set, shagreen patches and cephalic fibrous plaques were more frequently recorded in the NHD for Black individuals.

Conclusion

We highlight a disparity in the representation of Black participants within the NHD, TSCOE, and TSC trials, in addition to differences in utilization of molecular testing and topical mechanistic target of rapamycin (mTOR) inhibitor therapy between Black and White individuals. We show a trend toward later diagnosis age in Black individuals. These differences between races warrant further study across additional clinical sites and other minority groups.

The Potential of Visceral Adipose Tissue in Distinguishing Clear Cell Renal Cell Carcinoma from Renal Angiomyolipoma with Minimal Fat

Purpose

To overcome the challenge of preoperative differentiation between clear cell renal cell carcinoma (ccRCC) and renal angiomyolipoma with minimal fat (RMFAML), we evaluated the potential of visceral adipose tissue (VAT) in distinguishing RMFAML from ccRCC.

Patients and Methods

Patients (191) were divided into ccRCC and RMFAML groups according to postoperative pathology. Umbilical horizontal computed tomography (CT) images were used for visceral fat area (VFA), subcutaneous fat area (SFA) and total fat area (TFA) measurements. Logistic regression was used to identify risk factors for ccRCC. Areas under the receiver operating characteristic (ROC) curve (AUCs) were compared to identify the most valuable indicator for identifying ccRCC and RMFAML.

Results

In total, 166 patients had ccRCC, and 25 had RMFAML. ccRCC and RMFAML patients showed significant differences in age (P<0.001), sex (P<0.001), hypertension (P=0.027), BMI (P<0.001), SFA (P=0.046), VFA (P<0.001) and TFA (P<0.001). According to multiple logistic regression analysis, male sex [4.311 (1.469~12.653), p=0.008]; older age [1.047 (1.008~1.088), p=0.017]; and higher BMI [1.305 (1.088~1.566), p=0.004], SFA [1.013 (1.003~1.023), p=0.008], VFA [1.026 (1.012~1.041), p<0.001] and TFA [1.011 (1.005~1.017), p=0.001] were associated with ccRCC. The AUCs of sex (male), age, BMI, TFA, VFA, and SFA were 0.726, 0.687, 0.783, 0.769, 0.840, and 0.645, respectively. The VFA cut-off value was 69.99 cm². The sensitivity and specificity of higher VFA (≥69.99 cm²) for ccRCC diagnosis were 79.52% and 80.00%, respectively.

Conclusion

In differentiating ccRCC from RMFAML, male sex, older age, and higher BMI, TFA, SFA, and VFA are risk factors for ccRCC. VFA is the most effective indicator for identifying ccRCC.

Renal hematuric angiomyolipomas embolization: three cases and literature review

We report three cases of hemorrhagic renal angiomyolipoma successfully treated using embolization. Endovascular management of this complication is highlighted.

Different Treatments of Symptomatic Angiomyolipomas of the Kidney: Two Case Reports

Development of more sensitive imaging techniques has caused an increase in the number of diagnosed small renal tumors. Approximately 2-3% of these lesions are proved to be angiomyolipomas (AML), a rare benign tumor of the kidney sometimes causing pain and hematuria. The most required approach is observation, but in the case of recurrent symptoms or larger tumors, which may cause bleeding, a more active treatment is required. We present two cases of symptomatic AML tumors of different sizes in the kidney: one treated with transarterial embolization (TAE), and the other with percutaneous cryoablation (CRA). The lesions were diagnosed on the basis of contrast-enhanced computed tomography (CT) scan and magnetic resonance imaging (MRI). Both treatments proved to be effective and safe for treating renal AMLs. A follow-up carried out, based on contrast-enhanced CT scan, confirmed complete treatment of AML and decreased lesion size. There are myriad minimally invasive approaches for the treatment of renal AMLs, and the preservation of renal function remains a priority. The most popular treatment option is the selective renal artery embolization. Owing to its limited invasiveness, CRA could be an attractive option for the preventive treatment of AML.

Endovascular treatment of intrarenal aneurysms bleeding and angiomyolipomas in a patient with tuberous sclerosis and polycystic kidney disease

Tuberous sclerosis complex (TSC) and autosomal dominant polycystic kidney disease (ADPKD) are conditions related to renal failure that can rarely occur in association as a contiguous gene syndrome. Angiomyolipomas (AMLs) are renal tumors strongly related to TSC that may rupture and cause life-threatening bleedings. We present a patient with TSC, ADPKD, and renal AMLs with persistent hematuria requiring blood transfusion. The persistent hematuria was successfully treated through endovascular embolization, a minimally invasive nephron sparing technique.

Utility of contrast-enhanced ultrasound for solid mass surveillance and characterization in children with tuberous sclerosis complex: an initial experience

BACKGROUND

Patients with tuberous sclerosis complex (TSC) can develop solid kidney masses from childhood. Imaging surveillance is done to detect renal cell carcinoma (RCC) and angiomyolipomas (AML), including AMLs at risk for hemorrhage. Intravenous contrast-enhanced ultrasound (CEUS) may be useful for screening as ultrasound is well tolerated by children and ultrasound contrast agents (UCA) are not nephrotoxic.

METHODS

Retrospective review of kidney CEUS exams of pediatric TSC patients. Qualitative CEUS analysis by consensus of 3 radiologists assessed rate, intensity, and pattern of lesion enhancement. Quantitative CEUS analysis was performed using Vuebox®. Where available, abdominal MRI was analyzed qualitatively for the same features and quantitatively by in-house-developed software. Time-intensity curves were generated from both CEUS and MRI where possible. Appearance of lesions were compared between CEUS and MRI and histology where available.

RESULTS

Nine masses in 5 patients included one histologically proven RCC and 8 AMLs diagnosed by imaging. Quantitative CEUS of RCC showed malignant features including increased peak enhancement 162%, rapid wash-in rate 162%, and elevated washout rate 156% compared to normal kidney tissue; versus AML which was 68%, 105%, and 125%, respectively. All masses were hypoenhancing on MRI compared to normal kidney tissue; MR dynamic contrast study offered no distinction between RCC and AML. The only MRI feature differentiating RCC from AML was absence of fat.

CONCLUSION

Temporal resolution afforded by CEUS was useful to distinguish malignant from benign kidney masses. CEUS may prove useful for screening, characterizing, and follow-up of kidney lesions in pediatric TSC patients.

Renal tumors in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is a multisystem hereditary disorder characterized by the growth of benign tumors (hamartomas) in multiple organs, including the kidneys. Renal angiomyolipomas (AML) are a major diagnostic feature of TSC and are present in the majority of patients by adulthood. However, AML are usually asymptomatic during childhood when neurological and developmental manifestations are the main source of morbidity. Kidney manifestations of TSC have historically been the main cause of morbidity and mortality of adults with TSC. The recognition that the complications of TSC are caused by dysregulation of the mammalian target of rapamycin (mTOR) pathway has led to an enormous progress in the management of patients with TSC in the last two decades, the establishment of diagnostic guidelines, and trials which have shown the therapeutic benefit of mTOR inhibitors. Kidney surveillance of children with TSC now provides the opportunity for timely interventions to reduce the impact of TSC in adulthood. In this review, we discuss the current management of kidney tumors associated with TSC, including the diagnosis, surveillance, and treatment options for these lesions. We also present outcome data from international registries demonstrating the effectiveness of the current management strategies. With clear management guidelines and efficient treatment of kidney tumors, we envisage that the long-term outcomes of patients with TSC will further improve in the future.

The effect of sirolimus on angiomyolipoma is determined by decrease of fat-poor compartments and includes striking reduction of vascular structures

Renal angiomyolipomas hemorrhage is associated with their size and vascular constitution. The effects of sirolimus on different components of angiomyolipomas was analyzed in patients with tuberous sclerosis complex, sporadic lymphangioleiomyomatosis and multiple sporadic angiomyolipomas. Thirty angiomyolipomas from 14 patients treated with sirolimus were retrospectively evaluated. A Hounsfield-unit threshold was used to classify angiomyolipomas in fat-rich, fat-poor and intermediate-fat tumors, and to categorize tumor compartments in fat rich, fat poor, intermediate fat and highly vascularized. Diameter variations were measured to assess the effects on aneurysmatic/ectatic vascular formations. Volume reduction following treatment with sirolimus was higher in fat-poor than fat-rich angiomyolipomas. Tumor reduction was mainly determined by decrease of the fat-poor and highly-vascularized compartments while the volume of the fat-rich compartment increased. Broad liposubstitution was observed in some tumors. A median reduction of 100% (75 to 100) in the diameter of aneurysmatic/ectatic vascular structures was observed. Our study showed that sirolimus reduces the size of angiomyolipomas by decreasing primarily their highly-vascularized and fat-poor compartments. This effect is associated with a remarkable reduction of tumoral aneurysms/ectatic vessels, revealing the likely mechanism responsible for the risk-decreasing effect of mTOR inhibitors on angiomyolipoma bleeding. These findings support the role of mTOR in the development of angiomyolipoma blood vessels.

Kidney Imaging Surveillance in Commercially Insured Patients With Tuberous Sclerosis Complex

BACKGROUND

Kidney disease has historically been the primary source of early mortality in adults with tuberous sclerosis complex (TSC). Kidney imaging surveillance promotes early detection of lesions requiring intervention. We describe kidney imaging frequency in relationship to patient-level characteristics for commercially insured patients with TSC in the United States.

METHODS

This retrospective observational study used 2003 to 2016 enrollment and claims data from a de-identified fully insured commercial health insurer. Patients with TSC less than 65 years were included. The patient-level kidney imaging rate was calculated as the number of kidney imaging procedures divided by length of continuous enrollment. A multiple linear regression model was used to determine the relationship between imaging rate and progression of TSC-associated kidney disease, number of specialists seen, and nephrologist care.

RESULTS

At least half of the 70 patients with TSC included in the study were aged 16 years or younger. Over a follow-up period of up to 14 years, the median kidney imaging rate was 0.13 procedures per year with 43% (N = 30) of patients lacking evidence of kidney imaging during the observation period. Imaging frequency increased with progression of TSC-associated kidney disease, more specialists, and nephrologist care (P < 0.05 for all three in regression model).

CONCLUSIONS

A substantial percentage of patients with TSC in the United States are at risk for delayed detection of kidney manifestations due to infrequent kidney imaging surveillance. Multispecialty care, including neurologists, may positively affect kidney surveillance rates.

Renal angiomyolipoma rupture in a young female with COVID-19

While primarily a respiratory illness, infection with the novel coronavirus (COVID-19) is associated with pathologic changes in coagulation, characterized by both thromboembolic and bleeding events. We present the case of a 22-year-old female diagnosed with renal angiomyolipoma (AML) rupture 2 weeks after COVID-19 infection, ultimately requiring admission for hemorrhage control via endovascular embolization. Emergency medicine physicians should maintain a high index of suspicion for renal AML rupture and other spontaneous bleeding events in patients with recent COVID-19 infection due to a possible correlation between the two.

Evidence-based protocol-led management of renal angiomyolipoma: A review of literature

Renal angiomyolipomas (R-AMLs) are rare benign tumors, which occur sporadically and in association with genetic conditions such as tuberous sclerosis complex (TSC) and lymphangioleiomyomatosis (LAM). The key clinical concern is life-threatening hemorrhage. There is uncertainty about the optimal management strategy for patients with R-AMLs. We aim to review the evidence and provide a protocolled approach for the management of R-AMLs. A literature search of R-AML was conducted using MEDLINE and EMBASE for articles published between January 1990 and March 2020. Patient with TSC and sporadic cases were included. Treatment strategies, including active surveillance, surgery, selective arterial embolization (SAE), ablation, and systemic therapies, were reviewed. Outcomes from contemporary case series of active surveillance, surgery, and SAE were collated. There were no randomized controlled trials on this topic. The retrospective case series reviewed showed that many R-AMLs can be managed safely with active surveillance. Tumor size is the most important predictor of bleeding, and other factors such as rate of growth, women of child-bearing age, aneurysm size, and symptoms should be considered when deciding on prophylactic treatment. There is limited evidence for the traditional 4-cm cutoff for treatment, which may lead to overtreatment. The primary intervention options are SAE and surgery; whereas SAE is a less invasive option, nephron sparing surgery offers a lower risk of recurrence. Both appear to have similar morbidity, and the current evidence does not recommend one over the other in most cases. Thermal ablation has promising results but has only been trialed in small case series. Patients with TSC can be offered mammalian target of rapamycin inhibitors of which everolimus appears to cause the greatest shrinkage of tumors with an acceptable side-effect profile. R-AMLs should be assessed for their risk of bleeding. Low-risk tumors should be treated with active surveillance. High-risk tumors should be treated with SAE or surgery. Systemic treatments are the first-line of treatment for patients with TSC to preserve renal parenchyma.

Enhancing disease awareness for tuberous sclerosis complex in patients with radiologic diagnosis of renal angiomyolipoma: an observational study

Background

Tuberous Sclerosis Complex (TSC) is a genetic disorder, with renal manifestations like angiomyolipoma (AML) occurring in 70–80% of patients. AML usually cause more complications in TCS patients than in non-TSC patients. However, AML patients are not routinely investigated for TSC. Our aim was to retrospectively assess the correlation between radiologically diagnosed AML and TSC.

Methods

All patients were stratified into AML related vs. unrelated to TSC. Correlations were calculated to determine the association between age, AML, and TSC.

Results

Complete data were available for 521 patients with renal AML, in 7 of which the concurrent diagnosis of TSC was found. Younger age significantly positively correlated with the prevalence of TSC in AML patients (p <  0.01). 37 (7%) of the 521 patients were within the age-range of 18–40 years, in which TSC occurred in 6 cases, 4 (66.7%) of which presented with multiple, bilateral renal AML (p <  0.05), and 2 (33.3%) of which with a single, unilateral AML (p <  0.05). In patients with AML but without TSC, unilateral AML was found in 83.9% and bilateral AML in 16.1% (p <  0.05). Simple binary logistic regression analysis revealed bilateral AML (OR 33.0; 95% CI 3.2–344.0; p = 0.003) (but not unilateral AML (OR 0.09; 95% CI 0.01–0.88; p = 0.04)) to be a risk factor for TSC.

Conclusions

The presence of bilateral AML in patients within the age-range of 18–40 years should raise suspicion for TSC as the underlying cause. Therefore, our advice is to refer patients with multiple bilateral renal AML for further investigations regarding TSC.

Everolimus in Invasive Malignant Renal Epithelioid Angiomyolipoma

Background

To evaluate the efficacy and safety of everolimus, a mTOR inhibitor, on invasive malignant renal epithelioid angiomyolipoma (EAML).

Materials and Methods

From Oct 2014 to May 2019, we collected data from seven patients with a definite (clinical and pathological) diagnosis of EAML received everolimus in our hospital. Targeted sequence capture array technique with next-generation of high throughput sequencing (NGS) were performed to detect mutations of TSC1/2 genes. All patients had received surgery and everolimus. The clinical efficacy and safety of the therapy were evaluated.

Results

Mutations of TSC1 and TSC2 were detected in two and three patients though targeted sequence capture array technique with NGS, respectively. Among seven patients, three had missense mutations, one had nonsense mutation, and one had the large fragment deletion mutation. Five patients accompanied with tuberous sclerosis complex (TSC) were identified. All patients were administered 10mg everolimus once daily, the treatment duration lasted for 3 to 28 months. The objective response was assessed 3 months later, five partial response, two stable disease (SD), the mean greatest tumor diameter of all patients decreased from 9.6 to 5.2cm. Six patients stayed SD and one patient died during follow up. Patients accompanying with TSC had better responses to everolimus compared with non-TSC.

Conclusion

The mTOR inhibitor can be an effective treatment for patients with invasive malignant renal EAML. Patients with TSC may benefit more from the therapy.

Management of a Patient with Tuberous Sclerosis with Urological Clinical Manifestations

The tuberous sclerosis complex (TSC) is highly variable as far as its clinical presentation is concerned. For the implementation of appropriate medical surveillance and treatment, an accurate diagnosis is compulsory. TSC may affect the heart, skin, kidneys, central nervous system (epileptic seizures and nodular intracranial tumors—tubers), bones, eyes, lungs, blood vessels and the gastrointestinal tract. The aim of this paper is to report renal manifestations as first clinical signs suggestive of TSC diagnosis. A 20-year-old patient was initially investigated for hematuria, dysuria and colicky pain in the left lumbar region. The ultrasound examination of the kidney showed bilateral hyperechogenic kidney structures and pyelocalyceal dilatation, both suggestive of bilateral obstructive lithiasis, complicated by uretero-hydronephrosis. The computer tomography (CT) scan of the kidney showed irregular kidney margins layout, undifferentiated images between cortical and medullar structures, with non-homogenous round components, suggestive of kidney angiomyolipomas, bilateral renal cortical retention cysts, images of a calculous component in the right middle calyceal branches and a smaller one on the left side. The clinical manifestations and imaging findings (skull and abdominal and pelvis CT scans) sustained the diagnosis.

Metformin effectively treats Tsc1 deletion-caused kidney pathology by upregulating AMPK phosphorylation

Tuberous sclerosis complex (TSC) is characterized by hamartomatous lesions in multiple organs, with most patients developing polycystic kidney disease and leading to a decline of renal function. TSC is caused by loss-of-function mutations in either Tsc1 or Tsc2 gene, but currently, there is no effective treatment for aberrant kidney growth in TSC patients. By generating a renal proximal tubule-specific Tsc1 gene-knockout (Tsc1 ptKO) mouse model, we observed that Tsc1 ptKO mice developed aberrantly enlarged kidneys primarily due to hypertrophy and proliferation of proximal tubule cells, along with some cystogenesis, interstitial inflammation, and fibrosis. Mechanistic studies revealed inhibition of AMP-activated protein kinase (AMPK) phosphorylation at Thr-172 and activation of Akt phosphorylation at Ser-473 and Thr-308. We therefore treated Tsc1 ptKO mice with the AMPK activator, metformin, by daily intraperitoneal injection. Our results indicated that metformin increased the AMPK phosphorylation, but decreased the Akt phosphorylation. These signaling modulations resulted in inhibition of proliferation and induction of apoptosis in the renal proximal tubule cells of Tsc1 ptKO mice. Importantly, metformin treatment effectively prevented aberrant kidney enlargement and cyst growth, inhibited inflammatory response, attenuated interstitial fibrosis, and protected renal function. The effects of metformin were further confirmed by in vitro experiments. In conclusion, this study indicates a potential therapeutic effect of metformin on Tsc1 deletion-induced kidney pathology, although currently metformin is primarily prescribed to treat patients with type 2 diabetes.

Effect of everolimus on renal function in patients with tuberous sclerosis complex: evidence from EXIST-1 and EXIST-2

Background

A reduction in renal angiomyolipoma volume observed with everolimus (EVE) treatment in patients with tuberous sclerosis complex (TSC) has been postulated to translate to clinical benefit by reducing the risk of renal hemorrhage and chronic renal failure.

Methods

The long-term effects of EVE on renal function (∼4 years of treatment) were examined in patients treated with EVE in the Phase 3 EXIST-1 and EXIST-2 studies. Patients in EXIST-1 had TSC and subependymal giant cell astrocytoma (SEGA), and patients in EXIST-2 had renal angiomyolipoma and a definite diagnosis of TSC or sporadic lymphangioleiomyomatosis. EVE was administered at 4.5 mg/m²/day, with adjustment to achieve target trough levels of 5–15 ng/mL in EXIST-1 and at 10 mg/day in EXIST-2. Estimated glomerular filtration rate (eGFR) and creatinine levels were assessed at baseline, at Weeks 2, 4, 6, 8, 12 and 18, then every 3 months thereafter. Proteinuria was graded according to National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0.

Results

A total of 111 patients from EXIST-1 and 112 patients from EXIST-2 were included in this analysis. Respective mean ages at EVE initiation were 10.5 [standard deviation (SD) 6.45] and 33.2 (SD 10.29) years, and 3.6% and 37.5% of patients had undergone prior renal intervention. Mean baseline eGFR was 115 and 88 mL/min/1.73 m² in EXIST-1 and EXIST-2, respectively. Overall, mean eGFR remained stable over time in both studies, with an decline in renal function mostly confined to some patients with severely compromised renal function before treatment. Patients with prior renal intervention exhibited low eGFR values throughout the study. The incidence of proteinuria increased after initiating treatment with EVE and was mostly Grade 1/2 in severity, with Grade 3 proteinuria reported in only two patients. Measurements of proteinuria were limited by the use of urine dipstick tests.

Conclusions

The use of EVE does not appear to be nephrotoxic in patients with SEGA or renal angiomyolipoma associated with TSC and may preserve renal function in most patients.

ClinicalTrials.gov identifiers NCT00789828 and NCT00790400

The efficacy and safety of pharmacological treatments for lymphangioleiomyomatosis

Background

Lymphangioleiomyomatosis (LAM) is a rare, low-grade multisystem neoplastic disease. Most LAM patients are at a high risk of losing lung function at an accelerated rate and developing progressive dyspnea. Recently, several studies have reported their experience with pharmacological treatments for LAM. Therefore, we conducted a systematic review and meta-analysis to assess the efficacy and safety of these therapies.

Methods

PubMed (Medline), EMBASE, Cochrane Library, Web of Science and EBSCO Host were searched (until March 31, 2019) for eligible prospective studies regarding LAM patients treated with pharmacological treatments. Random effect models were used for quantitative analysis.

Results

Fourteen prospective studies regarding five pharmacological treatments (including sirolimus, everolimus, doxycycline, triptorelin, and a combination therapy of sirolimus and hydroxychloroquine) were enrolled in our systematic review, and ten of them were used for the meta-analysis. Seven prospective studies reported that sirolimus was effective at improving or stabilizing lung function and alleviating renal angiomyolipoma (AML) in LAM patients. Subsequent quantitative analyses showed that during sirolimus treatment, the pooled values of lung function and 6-min walk distance (6MWD) were not significantly changed (P > 0.05), with the pooled response rate of AML being 0.62 (95% confidence intervals [CIs]: 0.43 to 0.82, I² = 65%). Regarding everolimus, three prospective studies reported similar effects to those of sirolimus with regard to preserving lung function and reducing AMLs. The meta-analysis showed that the changes in lung function during everolimus treatment were not statistically significant (P > 0.05), while the pooled response rate of AML was 0.78 (95% CI: 0.68 to 0.88, I² = 8%). Neither the qualitative nor the quantitative results confirmed the benefits of doxycycline or triptorelin treatment, and the effects of the combination therapy were unclear in LAM patients. Most of the adverse events during pharmacological treatments were low or moderate grade and tolerable.

Conclusions

Overall, sirolimus and everolimus were recommended for the treatment of LAM because they could stabilize lung function and alleviate renal AML. Doxycycline and triptorelin were not recommended for the treatment of LAM because no beneficial outcomes were consistently observed. The efficacy and safety of combination therapy remain to be further explored.

Renal angiomyolipoma with tuberous sclerosis complex: How it differs from sporadic angiomyolipoma in both management and care

Renal angiomyolipoma (AML) is the most common benign tumor of the kidney. It consists of blood vessels, smooth muscle and fat components in varying proportions. AML is divided into the sporadic type and tuberous sclerosis complex (TSC)-associated type. TSC-associated AML develops at a younger age and tends to exhibit a much faster growth rate over time than sporadic AML. AMLs are classified as classic AML, fat-poor AML and epithelioid AML. Epithelioid AML, though rare, shows aggressive behavior leading to distant metastasis and mortality. TSC-associated AML is more likely to have an epithelioid component than sporadic AML. Active surveillance is the suggested management for small AML. Clinical intervention is mainly indicated when there is a substantial risk of rupture. Minimally invasive therapies, including partial nephrectomy, transcatheter arterial embolization, and mammalian target of rapamycin (mTOR) inhibitor treatment are employed for patients who require treatment. An updated algorithm for the management of AML is herein described. According to this algorithm, treatment intervention is recommended for TSC-associated AML >3 cm, even in asymptomatic cases. In cases with asymptomatic sporadic AML >4 cm in size or with an intra-tumoral aneurysm of >5 mm, treatment, including transcatheter arterial embolization or partial nephrectomy, is advised. The major complication of AML is intra-tumoral or retroperitoneal hemorrhage due to rupture that may be serious and life threatening. Thus, correct diagnosis, proper observation, and appropriate treatment are very important in the management of renal AML.

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.

Renal angiomyolipoma (AML) harboring a missense mutation of TSC2 with copy-neutral loss of heterozygosity (CN-LOH)

Angiomyolipoma (AML) is classified as a perivascular epithelioid cell neoplasm, mostly occurring in the kidney. Twenty percent of patients with renal AML have tuberous sclerosis complex (TSC) caused by germline variation in the TSC1 or TSC2 gene. In this paper, we report the first case of renal AML harboring somatic missense mutations of the TSC2 gene and concomitant copy-neutral loss of heterozygosity (CN-LOH). The patient presented with solitary renal AML and pulmonary lymphangiomyomatosis and without other findings suggestive of TSC. Exome sequencing analysis of the renal AML, however, identified a pathogenic somatic missense mutation in the TSC2 gene (NM_000548:c.5228G>A:p. R1743Q), although no other somatic mutation was detected. Furthermore, no germline mutation in TSC1 or TSC2 was detected. Interestingly, the mutant allele ratio was too high for a somatic heterozygous mutation without loss of heterozygosity (LOH). Furthermore, no copy number variation was detected around the TSC2 locus (16p13.3). To clarify the allelic status, we analyzed heterozygous single-nucleotide polymorphisms (SNPs) in chromosome 16. In these SNPs, an unbalanced allele ratio was accumulated inside the 16p13.3 region. These results suggested copy-neutral LOH (CN-LOH). Consequently, we concluded that the missense mutation of the TSC2 gene and CN-LOH of the TSC2 locus caused renal AML.

Quantitative Analysis of Multiphase Contrast-Enhanced CT Images: A Pilot Study of Preoperative Prediction of Fat-Poor Angiomyolipoma and Renal Cell Carcinoma

OBJECTIVE. The objective of our study was to preoperatively predict fat-poor angiomyolipoma (fp-AML) and renal cell carcinoma (RCC) by conducting quantitative analysis of contrast-enhanced CT images. MATERIALS AND METHODS. One hundred fifteen patients with a pathologic diagnosis of fp-AML or RCC from a single institution were randomly allocated into a train set (tumor size: mean ± SD, 4.50 ± 2.62 cm) and test set (tumor size: 4.32 ± 2.73 cm) after data augmentation. High-dimensional histogram-based features, texture-based features, and Laws features were first extracted from CT images and were then combined as different combinations sets to construct a logistic prediction model based on the least absolute shrinkage and selection operator procedure for the prediction of fp-AML and RCC. Prediction performances were assessed by classification accuracy, area under the ROC curve (AUC), positive predictive value, negative predictive value, true-positive rate, and false-positive rate (FPR). In addition, we also investigated the effects of different gray-scales of quantitative features on prediction performances. RESULTS. The following combination sets of features achieved satisfying performances in the test set: histogram-based features (mean AUC = 0.8492, mean classification accuracy = 91.01%); histogram-based features and texture-based features (mean AUC = 0.9244, mean classification accuracy = 91.81%); histogram-based features and Laws features (mean AUC = 0.8546, mean classification accuracy = 88.76%); and histogram-based features, texture-based features, and Laws features (mean AUC = 0.8925, mean classification accuracy = 90.36%). The different quantitative gray-scales did not have an obvious effect on prediction performances. CONCLUSION. The integration of histogram-based features with texture-based features and Laws features provided a potential biomarker for the preoperative diagnosis of fp-AML and RCC. The accurate diagnosis of benign or malignant renal masses would help to make the clinical decision for radical surgery or close follow-up.

Recommendations for the management of renal involvement in the tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is a rare, hereditary, multisystemic disease with a broad phenotypic spectrum. Its management requires the collaboration of multiple specialists. Just as in the paediatric age, the paediatric neurologist takes on special importance; in adulthood, renal involvement is the cause of the greatest morbidity and mortality. There are several recommendations on the general management of patients with TSC but none that focuses on renal involvement. These recommendations respond to the need to provide guidelines to facilitate a better knowledge and diagnostic-therapeutic management of the renal involvement of TSC through a rational use of complementary tests and the correct use of available treatments. Their elaboration has been based on consensus within the hereditary renal diseases working group of the SEN/REDINREN (Spanish Society of Nephrology/Kidney Research Network). It has also counted on the participation of non-nephrologist specialists in TSC in order to expand the vision of the disease.

Bleeding angiomyolipoma mimiking a ruptured adrenal tumour

Angiomyolipoma is a benign neoplasm of the kidney, and is the most common renal tumour associated with haemorrhage. Risk of bleeding increases with the size of the angiomyolipoma. We report a case of spontaneous bleeding from an upper polar renal angiomyolipoma mimicking a spontaneous adrenal bleed from a pheochromocytoma.

Two novel TSC2 mutations in renal epithelioid angiomyolipoma sensitive to everolimus

People who suffers renal angiomyolipoma (AML) has a low quality of life. It is widely known that genetic factors including TSC2 mutation contribute to certain populations of renal AML-bearing patients. In this study, we are the first to identify novel TSC2 mutations in one Chinese renal epithelioid AML patient: c.2652C>A; c.2688G>A based on sequencing result from biopsy tissue. These two somatic mutations cause a translational stop of TSC2, which leads to mTORC1 activation. Given the fact that activation of mTORC1 ensures cell growth and survival, we applied its inhibitor, FDA-approved everolimus, to this woman. After months of treatment with everolimus, Computer-Tomography (CT) scan results showed that everolimus successfully reduced tumor growth and distal metastasis and achieved partial response (PR) to everolimu according to Response Evaluation Criteria in Solid Tumors (RECIST version 1.1). Further Blood Routine Examination results showed the concentration of red cell mass, hemoglobin, white blood cell (WBC), platelets and hematocrit (HCT) significantly returned to normal levels indicating patients with these two TSC2 mutations could be effectively treated by everolimus.

Mutational analysis of renal angiomyolipoma associated with tuberous sclerosis complex and the outcome of short-term everolimus therapy

To identify clinical characteristics and mutation spectra in Chinese patients with renal angiomyolipoma (AML) associated with the tuberous sclerosis complex (TSC, TSC-AML), examined the efficacy and safety of short-term everolimus therapy (12 weeks). We analyzed the frequency distribution of each TSC-related clinical feature and investigated gene mutations by genetic testing. Some subjects received everolimus for 12 weeks at a dose of 10 mg/day, and the efficacy and safety of short-term everolimus therapy were examined. Finally, 82 TSC-AML patients were enrolled for analysis in this study. Of the 47 patients who underwent genetic testing, 22 patients (46.81%) had at least one detectable mutation in the TSC1 or TSC2 gene: 7 were TSC1 gene mutations, 13 were TSC2 gene mutations, and 2 were found in both TSC1 and TSC2. Everolimus treatment had a statistically significant effect on the renal AML volume reduction during follow-up (P < 0.05), and the mean reduction rate of volume for all cases was 56.47 ± 23.32% over 12 weeks. However, 7 patients (7/25; 28.00%) experienced an increase in renal AML tumor volume within 12 weeks after discontinuation of the everolimus treatment. Although most patients (27/30, 90.00%) experienced some adverse events during the treatment period, all such events were mild, and no patients discontinued or needed dose reduction because of adverse events. Overall, in this study, the mutation rate of TSC-AML patients is much lower than other reports. Short-term everolimus treatment for TSC-AML is effective and safe, but the stability is much lower than long-term therapy.

New MRI series for kidney evaluation: Saving time and money

OBJECTIVES

This study investigates the diagnostic performance of a new T1 imaging series, generated by the digital subtraction of the opposed phase from in phase T ₁ weighted images, in MRI for renal angiomyolipoma (AML) evaluation.

METHODS

This retrospective study involved 96 patients, 63 (65.6%) with at least one renal AML and 33 (34.4%) healthy patients. Two radiologists having different experience retrospectively reviewed two MR imaging series, starting with in and out-phase T ₁ weighted images and then the new subtracted T1 images, in which AML appeared white on black background. The presence, number, location, and dimensions of the AMLs, and reading time were collected separately for the two kidneys. Statistical analysis was carried out using the appropriate tests.

RESULTS

The number of lesions identified and the evaluation of lesion dimension did not statistically differ between the different MR imaging series evaluated, without interobserver variability. Both percentage agreement of the total number of observations and the κ coefficient showed very good agreement between the radiologists. The median time for the diagnosis was statistically lower when using the subtracted T1 imaging series for both observers with a median gain from 6.5 to 15 s per identified lesion, resulting in a total time-saving of more than half (52.9%), in both patients with and without AMLs, and in patients with a single or with more than one AML (p < 0.001).

CONCLUSIONS

The new subtracted T1 imaging series proved to be reliable in identifying fat-containing renal lesions, by both expert and non-expert radiologists, resulting in a saving of both time and money. Moreover, this new subtracted T1 imaging series could be an effective tool in non-dedicated kidney examinations in which a faster reading is advisable.

ADVANCES IN KNOWLEDGE

The opportunity of using a single set of MRI images in kidney evaluation for identifying fat-containing lesions, considerably reducing reading time, resulting in cost-effectiveness.

Late local, peritoneal and systemic recurrence of renal angiomyolipoma: A case report

Renal angiomyolipoma (AML) is a relatively rare tumor that is generally considered as merely benign. However, epithelioid AML (EAML), an uncommon subtype, is associated with potentially malignant behavior. We herein present the case of a 60-year old male patient who had undergone left nephrectomy with left adrenalectomy and lymphadenectomy for a renal tumor 12 years earlier, and presented to our hospital with dull abdominal pain. The histology report after the previous surgery had revealed an AML of the left kidney with a maximal diameter of 17 cm. Imaging studies demonstrated a large tumor of 13 cm in diameter in the area of the resected kidney, as well as hepatic and peritoneal metastases. Computed tomography-guided core needle biopsy of the mass and revision of the histology of the nephrectomy revealed an EAML. Four years after a two-stage resection of the recurrences the patient is in excellent condition and free of disease. From this case report and the literature review on EAML, it appears that correct histological diagnosis of this subtype of renal AML is crucial. Erroneous diagnosis of simple renal AML instead of EAML may lead to insufficient postoperative management. Clinicians should be aware of the malignant potential of EAML and the need for long-term follow-up. As effective surgical and emerging medical treatment options are available, timely detection of recurrent disease may lead to improved outcome.

Lymphangioleiomyomatosis (LAM) presenting as recurrent pneumothorax in an infant with tuberous sclerosis: treated successfully with sirolimus

Lymphangioleiomyomatosis (LAM) either sporadic or a part of tuberous sclerosis complex is rare in paediatric age group. Here, we report a case of LAM with tuberous sclerosis in an infant. She was referred to our institute at the age of 4 months as a case of recurrent bilateral pneumothorax requiring intercostal tube drainage. Detailed history revealed that patient was symptomatic since 1 month of age in the form of seizures. She had respiratory symptoms for last 15 days. General physical examination revealed whitish macular patches. Brain imaging was suggestive of cortical tubers and subependymal nodules. The echocardiography showed right atrial rhabdomyoma. Chest CT revealed multiple cysts suggesting LAM. On the basis of above findings, a diagnosis of tuberous sclerosis complex with LAM was made. The infant was started on sirolimus and there was significant clinical and radiological improvement over a period of 2 and half years without any side effects.

Short-term safety of mTOR inhibitors in infants and very young children with tuberous sclerosis complex (TSC): Multicentre clinical experience

OBJECTIVE

To evaluate the safety of mTOR inhibitors (sirolimus or everolimus) in infants and very young children with tuberous sclerosis complex (TSC) under two years of age.

METHODS

Study design was retrospective to capture medical record data from 52 international TSC Centres who initiated treatment with sirolimus or everolimus in TSC children before the age of two years. Data collection included demographic and clinical information including reason(s) for initiating treatment with mTOR inhibitors, treatment duration, dosing, and corresponding serum trough levels, response to treatment, and adverse events (AE).

RESULTS

19 of 52 (37%) TSC Centres reported treatment of at least one child with TSC under the age of two years with everolimus or sirolimus. Treatment-related data were provided for 45 patients meeting inclusion criteria. Everolimus was utilised 87% of the time, compared to 24% for sirolimus (5 subjects, 11%, were treated separately with both). Refractory epilepsy (45%) was the most common primary reason for initiating treatment and treatment was initiated on average at 11.6 ± 7.6 months of age. At least one AE, suspected or definitely treatment-related, occurred in 35 of 45 (78%) treated subjects. Most AEs were mild (Grade 1) or moderate (Grade 2) in severity and most commonly related to infections. Severe AE (Grade 3) was reported in 7 subjects (20%) and no life-threatening AE (Grade 4) or death/disability (Grade 5) was reported. Treatment was discontinued due to an AE in 9 of 45 (20%).

CONCLUSIONS

Everolimus, and to a lesser extent sirolimus, are increasingly being used to treat TSC infants and very young children for multiple TSC-associated clinical indications. While AEs were common, most were not severe and did not prevent continued treatment in the majority of this younger population.

Renal progression factors in young patients with tuberous sclerosis complex: a retrospective cohort study

BACKGROUND

Renal pathology in tuberous sclerosis complex (TSC) is characterized by the growth of angiomyolipoma and renal cysts, and in rare cases renal cell carcinoma. Other consequences of renal involvement in TSC, including hypertension, proteinuria, and hyperfiltration, are not well studied. We aimed to analyze the early manifestations of the renal TSC phenotype in a young TSC cohort and to explore common, modifiable risk factors.

METHODS

In this retrospective cohort study, TSC patients attending the TSC clinics of two tertiary hospitals were included. Data on demographics, history, genotype, kidney function, hematuria, proteinuria, blood pressure, and renal imaging were collected.

RESULTS

Eighty patients were included, with a median age of 0.8 years (0.0-63.0) at first presentation, and a median follow-up time of 10.2 (0.4-41.0) years. Mutation analysis was available in 64 patients (80%). Renal lesions (cysts or angiomyolipoma) were observed in 55/73 (75%). Thirty-two percent (19/60) were hypertensive, 8/51 (16%) had proteinuria, and 18/71 (25%) had hyperfiltration (median eGFR 154 ml/min/m²). Six (7.5%) patients had developed end stage renal disease at the last follow-up. No association was found between hyperfiltration, hypertension, or proteinuria and CKD ≥ 3. Cox regression showed a significant positive association between the presence of a renal intervention and CKD ≥ 3 (Hazard-Ratio 3.91, P < 0.05).

CONCLUSIONS

Besides renal cysts and angiomyolipoma, the modifiable progression factors hypertension, proteinuria, and hyperfiltration occur frequently and early in TSC patients. This represents a preventive treatment target.

Renal manifestation of tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is a tumor predisposition syndrome with significant renal cystic and solid tumor disease. It commonly causes several types of cystic disease and benign tumors (angiomyolipomata) in the kidneys that can both lead to significant premature loss of glomerular filtration rate. The main risks of angiomyolipomata, severe bleeding, loss of renal function, and pulmonary lymphangioleiomyomatosis, can be ameliorated by active surveillance and preemptive therapy with mTOR inhibitors. The cystogenic mechanism may involve primary cilia, but also appears to also involve a majority of normal tubular cells and may be driven by a minority of cells with mutations inactivating both their TSC1 or TSC2 genes. Malignant tumors are rare.

Disseminated Intravascular Coagulation After Embolization to Treat Acutely Bleeding Bilateral Massive Angiomyolipoma: A Case Report

Background: Hemorrhage from an angiomyolipoma (AML) of the kidney can be life threatening and arterial embolization is the primary treatment. Embolization is less invasive than surgery, is well tolerated, and major complications are rare. We describe a case of disseminated intravascular coagulation (DIC) after embolization of a bleeding renal AML in a 44-year-old man with massive bilateral AMLs. This report aims to highlight the possibility that acute DIC could be a major complication of embolization itself and so should be considered and screened for because, if present, it requires early and aggressive management. Case Presentation: A 44-year-old man with a history of large bilateral renal AMLs associated with tuberous sclerosis complex presented with visible hematuria and abdominal pain. Renal CT revealed bleeding from the right kidney. Embolization with polyvinyl alcohol and lipiodol was urgently performed. The following day he required multiple blood transfusions and repeat embolization, this time with gelfoam and "tornado" coils. He suddenly developed DIC, cardiovascular collapse and acute renal failure requiring many days in the intensive care unit for inotropic support and renal replacement therapy. Conclusion: Arterial embolization may be associated with increased risk of DIC in the setting of treating large bleeding renal AMLs. DIC may be a direct or indirect complication of this. The clinician must act quickly to identify this and treat this complication aggressively.