Evolving horizons in renal angiomyolipoma: two decades of management strategies and clinical perspectives in a single institutional study.

OBJECTIVE: To assess various management options for renal angiomyolipoma (AML) to guide clinical practice. METHODS: A single center retrospectively reviewed an AML series from 2002 to 2022. The image reports and chart reviews of patients who received two abdominal scans at least 6 months between the first and last scans were assessed. RESULTS: A total of 203 patients with 209 tumors were identified and followed up for a median of 42.6 months. Active surveillance (AS) was the most frequently selected option (70.9% of cases). Interventions were required for 59 AMLs, of which 20 were treated with embolization, 29 with partial nephrectomy, 9 with radical nephrectomy, and 1 with radiofrequency (RF) ablation. The median size of the lesions at intervention was 5 cm. The average growth rate of the lesions was 0.12 cm/year, and there was a significant difference in the average growth rate of lesions ≤4 cm and those >4 cm (0.11 vs. 0.24 cm/year; p = 0.0046). CONCLUSION: This series on AMLs confirms that lesions >4 cm do not require early intervention based on size alone. Appropriately selected cases of renal AML can be managed by AS.KEYWORDS: Angiomyolipoma; active surveillance; embolization; nephrectomy; nephron-sparing surgery.

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.

Comparison of Polyvinyl Alcohol Versus Combination of Lipiodol-Bleomycin Emulsion and NBCA-Lipiodol Emulsion for Renal Angiomyolipoma Embolization: A Prospective Randomized Study.

BACKGROUND. Consensus is lacking regarding optimal embolic agents for transcatheter arterial embolization (TAE) of renal angiomyolipomas (AMLs). OBJECTIVE. The purpose of our study was to compare the safety and efficacy of TAE with polyvinyl alcohol (PVA) and TAE with a combination of ethiodized oil (Lipiodol)-bleomycin emulsion and N-butyl cyanoacrylate (NBCA)-Lipiodol emulsion for the treatment of patients with large or symptomatic AMLs. METHODS. This prospective study enrolled patients referred for TAE of a large (> 4 cm) or symptomatic renal AML from July 2007 to December 2018. Patients were randomized to undergo TAE using PVA particles or a combination of Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion. Patients underwent serial clinical follow-up visits and follow-up CT or MRI examinations after TAE. Outcomes were compared between groups. RESULTS. Seventy-eight patients were enrolled. After exclusions, the analysis included 72 patients (15 men, 57 women; mean age, 35.0 years; 51 patients with hematuria, 66 patients with flank pain): 35 patients were randomized to treatment by PVA and 37 were randomized to treatment by a combination of Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion. Complete occlusion of all angiographically visible arterial supply was achieved in all patients. No major adverse event occurred in any patient. The mean follow-up after TAE was 77 ± 45 (SD) months (range, 37-180 months). The frequency of resolution of hematuria after initial TAE without recurrence was greater after treatment by Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion than by PVA (100.0% vs 80.0%, respectively; p = .03). At 12-month follow-up, the frequency of complete resolution of flank pain was higher after treatment by Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion than by PVA (100.0% vs 75.0%, p = .03). Mean reduction in AML volume at 36 months or longer after TAE versus at baseline was greater in patients treated by Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion than in those treated by PVA (98.0% vs 85.7%, respectively; p = .04). The frequency of complete response by modified RECIST (mRECIST) criteria at 36 months or longer after TAE was greater in patients treated by Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion than by PVA (94.6% vs 74.3%, p = .04). The rate of repeat TAE was higher among patients treated by PVA than among those treated by Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion (25.7% vs 8.1%, p = .04). CONCLUSION. Superior outcomes after TAE of AML were achieved using Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion than using PVA. CLINICAL IMPACT. TAE using a combination of Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion is a safe and effective treatment option for large or symptomatic AMLs. TRIAL REGISTRATION. Chinese Clinical Trial Registry ChiCTR2100053296.

Serum lactate dehydrogenase concentration after transcatheter renal artery embolization correlates with reduction in renal angiomyolipoma volume.

BACKGROUND: The extent of renal angiomyolipoma (AML) volume reduction after renal transcatheter arterial embolization (TAE) varies between patients, with no predictive measure available. PURPOSE: To determine whether the serum lactate dehydrogenase (LDH) concentration shortly after TAE correlates with the extent of tumor shrinkage. MATERIAL AND METHODS: In a cohort of 36 patients undergoing prophylactic renal TAE for unruptured renal AML, we retrospectively acquired data from patient medical records, including serum LDH before and within 7 days after TAE and the tumor volume before and 12-36 months after TAE. The relationship between the serum level of LDH and reduction in tumor volume was evaluated using Spearman correlation analysis. RESULTS: The median LDH concentration was significantly higher after TAE than before (909.0 U/L vs. 186.5 U/L). This early post-TAE serum LDH level and LDH index (post-TAE LDH / pre-TAE LDH) correlated significantly and positively with the absolute decrease in tumor volume (both P < 0.0001). We observed no significant correlation between the relative tumor volume reduction and serum LDH level or LDH index. CONCLUSION: Serum LDH elevation occurs shortly after TAE and correlates with the extent of absolute decrease in AML volume at 12-36 months after TAE. Further large-scale studies are warranted to confirm the predictive role of post-TAE serum LDH level and LDH index in tumor shrinkage in patients with unruptured renal AML.

Clinical Practice Guidelines for tuberous sclerosis complex-associated renal angiomyolipoma by the Japanese Urological Association: Summary of the update.

New clinical issues have been raised through an interval of 7 years from the previous version (2016). In this study, we update the "Clinical Practice Guidelines for tuberous sclerosis complex-associated renal angiomyolipoma" as a 2023 version under guidance by the Japanese Urological Association. The present guidelines were cooperatively prepared by the Japanese Urological Association and Japanese Society of Tuberous Sclerosis Complex; committee members belonging to one of the two societies or specializing in the treatment of this disease were selected to prepare the guidelines in accordance with the "Guidance for preparing treatment guidelines" published by Minds (2020 version). The "Introduction" consisted of four sections, "Background Questions (BQ)" consisted of four sections, "Clinical Questions (CQ)" consisted of three sections, and "Future Questions (FQ)" consisted of three sections (total: 14 sections). Concerning CQ, an agreement was confirmed through voting by the committee members based on the direction and strength of recommendation, accuracy of evidence, and recommendation comments. The present guidelines were updated based on the current evidence. We hope that the guidelines will provide guiding principles for the treatment of tuberous sclerosis complex-associated renal angiomyolipoma to many urologists, becoming a foundation for subsequent updating.

A Pilot First-in-Human Study of Embrace, a Polyethylene Glycol-Based Liquid Embolic Agent, in the Embolization of Malignant and Benign Hypervascular Tumors.

PURPOSE: To investigate the safety and efficacy of an aqueous polyethylene glycol-based liquid embolic agent, Embrace Hydrogel Embolic System (HES), in the treatment of benign and malignant hypervascular tumors. MATERIALS AND METHODS: A prospective, single-arm, multicenter study included 8 patients, 5 males and 3 females, with a median age of 58.5 years (30-85 years), who underwent embolization in 8 tumors between October 2019 and May 2020. Technical success was defined as successful delivery of HES to the index vessel, with disappearance of >90% of the targeted vascular enhancement or, for portal vein embolization, occlusion of the portal branches to the liver segments for future resection. The volume of HES administered, ease of use (5 point Likert scale), administration time, and adverse events (AEs) were recorded. Evaluation was performed at 7, 30, and 90 days via clinical assessment and blood testing, and follow-up imaging was performed at 30 days. RESULTS: Eight patients were enrolled, and 10 embolizations were performed in 8 lesions. Tumors included hepatocellular carcinoma (n = 4), renal angiomyolipoma (n = 3), and intrahepatic cholangiocarcinoma (n = 1). Technical success was 100%, and the average ease of use was 3.3 ± 1.0 SD. The HES delivery time was 1-28 minutes (median, 16.5 minutes), and the HES volume injected was 0.4-4.0 mL (median, 1.3 mL). All patients reached 30-day follow-up with imaging, and 6 patients reached 90-day follow-up. There were 3 serious AEs in 2 patients that were unrelated to the embolic agent. CONCLUSION: HES resulted in a 100% embolization technical success rate. The product ease of use was acceptable, and no target vessel recanalization was noted on follow-up imaging at 30 days.

Radiologic and clinical results of transarterial ethanol embolization for renal angiomyolipoma.

OBJECTIVE: We sought to determine the efficacy and safety of selective arterial embolization for renal angiomyolipoma (AML) using ethanol alone or ethanol with additional embolic materials and to analyze the factors influencing safety and efficacy. METHODS: One hundred nineteen AMLs treated with embolization were included retrospectively during a 15-year period. Technical, radiologic, and clinical success were recorded and risk factor analysis was performed. Complications on follow-up images, post-embolization syndrome (PES), major complications, and changes in renal function were also evaluated. RESULTS: Technical success was achieved in 106 of 119 tumors. Tumor size significantly decreased after treatment (reduction rate: 55%). Significant risk factors for tumor reduction included tumor enhancement on preprocedural CT and residual tumor staining. Radiologic success was achieved in 114 of 119 tumors (risk factor: residual tumor staining), and clinical success was achieved in 22 of 23 patients. Complications on follow-up images occurred in 40 of 119 tumors, and PES occurred in 53 of 104 patients. No major complications occurred. There were no cases of renal function impairment. CONCLUSION: Selective transarterial embolization using ethanol alone or ethanol with additional embolic materials reduced AML size, alleviated symptoms, and can be performed safely without permanent impairment. KEY POINTS: • Percutaneous transarterial ethanol embolization reduces AML size and alleviates symptoms. • Embolization can be performed safely without permanent impairment of renal function.

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.

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.

Varying Outcomes among Patients with Large Angiomyolipomas according to the Treatment Method.

PURPOSE: This study aimed to evaluate the outcomes of large angiomyolipoma (AML) treatment by selective arterial embolization (SAE) versus nephron-sparing surgery (NSS) using a robotic surgical system. MATERIALS AND METHODS: Between January 2011 and June 2018, we retrospectively reviewed 25 patients who underwent robot-assisted partial nephrectomy (RAPN) or SAE for large AMLs. Ten patients underwent RAPN, and 15 underwent SAE. Patient demographics, AML characteristics, and operative and postoperative clinical outcomes were recorded and analyzed. Outcomes were compared between patients who underwent RAPN and patients who underwent SAE. Specifically, changes in renal function and size were evaluated after the treatment. RESULTS: The mean age of the patients was 52.9 years, and 22 of 25 patients were female. The mean maximum AML diameter on computed tomography was 8.9 cm, and 8 patients had multiple masses. Twenty-two of 25 patients had moderate to high RENAL complexity. Patients who underwent SAE had more symptoms (p = 0.018) and higher RENAL complexity scores (p = 0.013) on average. On average, tumor size decreased by 99% among RAPN patients and by 58% among SAE patients (p = 0.001). Although the mean pretreatment estimated glomerular filtration rate (eGFR) was higher among RAPN patients (99.8 vs. 80.0 mL/min/1.73 m2, p = 0.043), there were no significant changes in eGFR in either group after the treatment. One patient in the RAPN group experienced complications, but the postoperative ileus resolved without intervention. CONCLUSIONS: Both RAPN and SAE were effective and feasible treatment options for large AMLs. The AML characteristics and the condition of the patient might be important in determining the appropriate treatment method.

Snuff box radial access in transcatheter arterial embolization for unruptured renal angiomyolipoma.

OBJECTIVE: We report the first three cases in which the feasibility and safety of the left snuff box radial access in transcatheter arterial embolization (TAE) for unruptured renal angiomyolipoma (AML) were evaluated. MATERIAL AND METHODS: Three patients with unruptured renal AMLs underwent TAE via the left snuff box radial artery. We retrospectively evaluated the characteristics of the AMLs, technical success rate, clinical success rate, and complications. Technical success and clinical success were defined as successful insertions of microballoon catheters selectively via the left distal radial artery into all intended arteries in a treatment session and shrinkage of tumor size as evaluated by CT or MRI after the procedure, respectively. RESULTS: The median size of the renal AMLs was 49 mm. TAE was successfully performed in all cases and all feeding arteries were successfully selected with a microballoon catheter through the left snuff box radial artery. The median amount of the mixture of ethanol and Lipiodol was 1.8 mL. Tumor shrinkage was confirmed in all with a median follow-up period of 6 months. The clinical success rate was 100%. No major complications occurred. CONCLUSION: The left snuff box access in TAE for an unruptured renal AML is safe and feasible.

[Results of active surveillance for sporadic renal angiomyolipomas greater than 4cm: A pledge for active surveillance]. / Résultats de la surveillance active des angiomyolipomes sporadiques du rein de plus de 4cm : un plaidoyer en faveur de la surveillance active.

INTRODUCTION: Active surveillance (AS) of sporadic renal angiomyolipomas (AML) is under-utilised because of an old dogma fearing a life-threatening retroperitoneal hemorrhage when tumour size exceeds 4cm. The objective of this study was to report the outcome of AS in patients with sporadic AML greater than 4cm. METHODS: The results of AS in 35 patients managed for sporadic renal AML greater than 4cm were analysed. During AS, tumour growth, occurrence of new symptoms and/or complications, discontinuation of AS protocol, reason for discontinuation as well as subsequent treatment options were reported. RESULTS: Within a median follow-up of 36 months, 16 (46 %) patients discontinued AS at the end of the study period (mean follow-up 55±66, median 36 months). Patients who discontinued AS were more symptomatic at diagnosis but had similar age, mean tumour size and sex ratio. Active treatment-free survival was 66 % at 5 years. Retroperitoneal hemorrhage was reported in 3 (8.5 %) patients. None of these bleedings required transfusion or monitoring in an intensive care unit. Other reasons for discontinuation were pain (37 %), patient preference (19), changes in the radiological appearance of the tumour (19 %), and hematuria (6 %). CONCLUSION: This study showed that AS in AML bearing patients was feasible even in the setting of tumours larger than 4cm. More than 50% of the patients were still on AS at 5 years. Discontinuation of AS was not related to bleeding complications in most cases. LEVEL OF PROOF: 3.

Spontaneous rupture of enormous renal angiomyolipoma in a pregnant tuberous sclerosis patient: a rare case.

BACKGROUND: Renal angiomyolipoma (RAML) is a rare benign kidney tumour comprised of adipose tissue, smooth muscle, and blood vessels. It can cause fatal complications if it ruptures. Although there have been reports of RAMLs rupturing, it is unusual to see RAMLs rupture during pregnancy, especially in pregnant women with tuberous sclerosis (TSC). Moreover, we reported a rare complication after selective arterial embolization (SAE) for the first time, which called aseptic liquefaction necrosis. CASE PRESENTATION: The case is a 16-week-pregnant woman with TSC who presented with severe flank pain, which was secondary to the rupture of a large, previously unknown RAML. This was confirmed by emergency computed tomography and successfully treated with selective arterial embolization after the patient received counselling and provided prior informed written consent for medical termination of pregnancy (MTP). The patient underwent abortion 3 weeks after the SAE. The patient required drainage 2 months after the SAE because of aseptic liquefaction necrosis. During follow-up, the patient's lesion remained stable. CONCLUSION: RAML rupture is a rare but rather serious complication in pregnant tuberous sclerosis patients. Selective arterial embolization (SAE) should be performed immediately, and the status of the pregnancy needs to be assessed by a multidisciplinary team. We also report for the first time the rare complication of aseptic liquefaction necrosis after SAE of RAML, for which percutaneous drainage is effective.

Hepatic angiomyolipoma: an international multicenter analysis on diagnosis, management and outcome.

BACKGROUND: Hepatic angiomyolipoma (HAML) may easily be misdiagnosed as a malignancy. The study aim was to assess diagnostic dilemmas, clinical management and outcome of this rare tumor. METHODS: This retrospective international multicenter study included all patients with pathologically proven HAML diagnosed between 1997 and 2017. Data on patient characteristics, diagnostic work-up, management and follow-up were analyzed. RESULTS: Thirty-eight patients were included, 32 female. Median age was 56yrs (i.q.r. 43-64) and median HAML-diameter was 57.5 mm (i.q.r. 38.5-95.3). Thirty patients had undergone CT and 27/38 MRI of the liver, diagnostic biopsy was performed in 19/38. Initial diagnosis was incorrect in 15/38 patients, of which 13 were thought to have malignancy. In 84% biopsy resulted in a correct preoperative diagnosis. Twenty-nine patients were managed with surgical resection, 4/38 with surveillance and 3/38 with liver transplantation. Recurrence after resection occurred in two cases. No HAML related deaths or progression to malignancy were documented. CONCLUSION: HAML diagnosis proved problematic even in hepatobiliary expertise centers. Biopsy is indicated and may provide valuable additional information when HAML diagnosis is considered on cross-sectional imaging, especially when surgical resection imposes a risk of complications. Conservative management with regular imaging follow-up might be justified when biopsy confirms (classic type) HAML.

Can we predict the existence of extrarenal feeders to renal angiomyolipomas?

OBJECTIVES: To identify factors predicting the presence of extrarenal feeders to renal angiomyolipomas (AMLs) METHODS: This is a retrospective study of 44 patients with 58 renal AMLs embolized in our department. Arteriography obtained during embolization and CT angiography obtained before and after embolization were reviewed to characterize AMLs with and without extrarenal feeders. Tumor characteristics were compared between the two groups. Simple logistic regression and ROC curve analysis were performed. P < 0.05 was considered to be statistically significant. RESULTS: Of the 58 AMLs reviewed, 29% had extrarenal arteries and 71% did not. AMLs with extrarenal feeders were significantly larger than those without, in terms of volume (median, 368 mL versus 109 mL, p < 0.0002) and the largest diameter (mean, 12.0 cm versus 7.7 cm, p < 0.0001). Patient age, presence of tuberous sclerosis complex or sporadic lymphangioleiomyomatosis, and tumor location did not differ between the groups. The largest diameter and volume had similar predictive values for the presence of extrarenal feeders (AUC, 0.83 versus 0.82, p = 0.673). Extrarenal feeders were present in 0%, 21%, and 79% of the AMLs ≤ 6.5 cm, AMLs 6.6-10.5 cm, and AMLs > 10.5 cm, respectively. CONCLUSIONS: AML size correlates with the presence of extrarenal feeders, with the largest diameter and volume being significant predictors. AMLs > 10.5 cm had a high chance of extrarenal feeders, making it mandatory to search for feeders to them in order to avoid incomplete embolization; AMLs ≤ 6.5 cm did not have extrarenal feeders, making a search for them unnecessary in these cases. KEY POINTS: • The presence of extrarenal feeders to renal angiomyolipoma is associated with tumor size, but not with patient age, concomitant disease, or tumor location. • The largest diameter and volume predict the presence of extrarenal feeders to AML, with similar predictive values. • AMLs > 10.5 cm have a high chance (79%) of extrarenal feeders, making it mandatory to search for feeders to them in order to avoid incomplete embolization; AMLs ≤ 6.5 cm do not have extrarenal feeders, making a search for them unnecessary in these cases.

Recurrent, Giant Renal Angiomyolipoma Treated with Selective Arterial Embolization: A Case Report.

Renal angiomyolipoma (AML), a rare benign mesenchymal neoplasm, is characterized by the presence of vessels, smooth muscle, and adipose tissue. Treatment should be considered for symptomatic patients or for those at risk for complications, in particular for retroperitoneal bleeding, which is correlated to the size of the tumor, grade of the angiogenic component, and presence of tuberous sclerosis complex. Herein, we report the case of a 39-year-old female with renal AML who was treated in a conservative approach by super-selective embolization.

Clinical behavior and management of three types of renal angiomyolipomas.

OBJECTIVES: To analyze and present the demography, clinical behavior, especially the risk factors of tumor hemorrhage and management of sporadic angiomyolipoma (SAML), tuberous sclerosis complex associated angiomyolipoma (TSCAML) and epithelioid angiomyolipoma (EAML) in our institution. METHODS: A retrospective study of 587 patients who were diagnosed with renal angiomyolipoma in our institution between January 2000 and May 2015 was done. The AMLs were diagnosed by ultrasonography, CT, or MRI. EAML was confirmed by histopathology. Medical records and follow-up results were analyzed using the SPSS version 22 software. RESULTS: Out of 587 cases of renal AMLs, 87.4% were SAMLs, 8.7% were TSCAMLs and 3.9% were EAMLs. Most of the AML patients were asymptomatic. The most common presenting symptoms included flank pain and abdominal pain. The median tumor size of SAML, TSCAML, EAML were 4.7, 2.7, 10.5 cm respectively. Approximately half of SAMLs were conservatively treated, almost all TSCAMLs were treated conservatively, while all EAMLs were surgically treated. The median tumor size of hemorrhagic SAML cases was 8 cm versus non-hemorrhagic cases of 4.1 cm. The optimal cut-off point on the ROC curve for predicting SAML tumor hemorrhage was 7.35 cm. CONCLUSION: A larger tumor size, younger patient's age and higher BMI value correlated with a higher risk of tumor hemorrhage. For tumor sizes less than 7.35 cm, we recommend active surveillance or TAE for hemorrhage prevention. We also suggest that surgical management should be considered for patients with tumors larger than 7.35 cm, symptomatic and progressive AML, or suspicious EAML.

Advanced sporadic renal epithelioid angiomyolipoma: case report of an extraordinary response to sirolimus linked to TSC2 mutation.

BACKGROUND: Renal epithelioid angiomyolipomas (EAML) are rare tumors with aggressive behavior. EAML can be sporadic or develop within the tuberous sclerosis complex syndrome, where mutations of TSC1 or TSC2 genes (critical negative regulators of mTOR Complex 1) result in an increased activation of mTOR pathway. Optimal EAML treatment, including mTOR inhibitors, remains undetermined. CASE PRESENTATION: Here we present the case of a young adult with a renal EAML that after radical nephrectomy developed metastases, first in liver and then in lumbar vertebrae. After complete surgical resection of these lesions, liver recurrence was detected, this time with incomplete surgical resection. After finding a new liver lesion, systemic treatment with sirolimus started. The patient exhibited a complete and durable response to this drug, being disease free at the time of publication, after 36 months of treatment. Targeted next generation sequencing (NGS) of MTOR, TSC1 and TSC2 genes in the primary tumor, metastasis and blood of the patient, revealed one inactivating TSC2 mutation (c.2739dup; p.K914*) in the tumor cells. Immunohistochemistry revealed decreased TSC2 protein content and increased phospho-S6 in the tumor cells, demonstrating mTOR pathway activation. CONCLUSION: NGS on an EAML patient with an extraordinary response to sirolimus uncovered TSC2 inactivation as the mechanism for the response. This study supports NGS as a useful tool to identify patients sensitive to mTOR inhibitors and supports the treatment of malignant EAML with these drugs.

Superselective Transcatheter Arterial Embolization for Large Unruptured Renal Angiomyolipoma in Lymphangioleiomyomatosis.

PURPOSE: To retrospectively evaluate therapeutic performance and complications of superselective transcatheter arterial embolization (TAE) for unruptured renal angiomyolipoma (AML) in patients with lymphangioleiomyomatosis (LAM) and to investigate the correlation between percentage reduction in tumor volume and intratumoral fat content. MATERIALS AND METHODS: Superselective TAE was performed in 14 consecutive patients with 15 large unruptured renal AMLs associated with LAM (mean age, 38 y; range, 21-57 y). Patients had renal AML with aneurysms ≥ 5 mm in diameter, tumor-related abdominal symptoms, or both. In all cases, embolization of 1 tumor was achieved in a single session by using multiporous gelatin sponge particles (GSPs) with additional metallic coils in all but 1 case. Tumor volume and fat content percentage were measured on CT or MR imaging before and after superselective TAE (median, 11 months; range, 6-14 months). RESULTS: Residual tumor staining declined by > 90% after all TAE sessions except 2, with embolization of all treated aneurysms. No nontarget embolization or severe complications were encountered. Mean percentage reduction in tumor volume after superselective TAE was 69% (range, 21%-95%). Percentage tumor volume reduction was negatively correlated with fat content before embolization (P < .01). CONCLUSIONS: Superselective TAE with multiporous GSPs and metallic coils for large unruptured renal AML in patients with LAM is useful for reducing tumor volume and treating intratumoral aneurysms without major pulmonary or renal complications. Extent of tumor reduction may be influenced by fat content before embolization.