Angiomyolipoma Research Articles

Predictors of Benignity for Small Endophytic Echogenic Renal Masses.

To evaluate for distinguishing demographic and sonographic features of small (<3 cm) endophytic angiomyolipomas (AMLs) that differentiate them from endophytic renal cell carcinomas (RCCs). This is a Health Insurance Portablitiy and Accountablity Act (HIPAA)-compliant retrospective review of the demographics and ultrasound features of endophytic renal AMLs compared to a group of endophytic RCCs. AMLs were confirmed by identifying macroscopic fat on computed tomography (CT) or magnetic resonance imaging (MRI), while RCCs were pathologically proven. Statistical analysis was used to compare findings in the 2 groups. There were a total of 66 patients with 66 AMLs, and 28 patients with 28 RCCs. Of the AMLs, 57 of 66 were in females, while 10 of the 28 RCC cases were in females (P < .0001). The mean AML long and short diameters were 11.0 × 9.3 mm and were statistically significantly smaller (P < .0001) than the diameters of the RCCs (23.4 × 22.1 mm). Likewise, the ratio of the long axis to the short axis measurement was statistically significantly different between the 2 groups (P < .0001). Of the studied sonographic features, statistically different features between AMLs and RCCs included an oval versus a round shape (P < .001), respectively, and the presence versus absence of an echogenic margin, respectively. Location of the mass, mass homogeneity, mass lobulation, and presence of cystic components were not distinguishing features using P < .01 levels. For an endophytic echogenic mass in a female patient, a small size with an oval shape and an echogenic margin is statistically more likely to be an AML than an RCC, which may be helpful with management decisions.

Wunderlich syndrome in pregnancy: life threatening bleeding renal angiomyolipoma in first and third trimesters—two case reports and literature review

BackgroundRenal angiomyolipoma (AML) is a prevalent benign tumour of the kidney. However, Wunderlich syndrome, marked by retroperitoneal haemorrhage, remains a rare and critical complication of large AMLs. During pregnancy, AMLs demonstrate an accelerated growth pattern and pose an elevated risk of rupture, leading to massive retroperitoneal haemorrhage. This report presents two compelling cases of life-threatening bleeding AML during the first and third trimesters, shedding light on the urgent need for heightened awareness and management strategies in pregnant women with AML. These cases underscore the novel and crucial aspect of the increased vulnerability of AMLs in pregnancy, emphasizing the importance of timely diagnosis and intervention.Cases presentationThe first patient is a 37-year-old lady who presented at 27 weeks of gestation with foetal distress, abdominal pain and hypovolemic shock. Emergency Caesarean section was performed for possible abruptio placenta, and a large non-expanding retroperitoneal hematoma was found intra-operatively. Post-delivery computed tomography (CT) angiography assessment showed left perinephric hematoma from bleeding AML at the lower pole. She was hemodynamically unstable after CT and underwent an emergency nephrectomy. Post-operative recovery was uneventful. The second patient is a 30-year-old lady who presented with right abdominal pain at 11 weeks of gestation with hypotension and an actively bleeding ruptured AML found on the abdominal MRI. She underwent angioembolization at 12 weeks of pregnancy with a radiation shield to protect the foetus. She recovered well after the procedure and continued her pregnancy. Her baby was born healthy at term with no evidence of any congenital malformation.ConclusionsWhen dealing with renal angiomyolipoma during pregnancy, multidisciplinary team management is crucial for the best management care. Stable cases can be treated conservatively, while unstable cases may require angioembolization or nephrectomy. The management plan should prioritize the best outcomes for both the mother and foetus. During the first trimester, angioembolization is safe and effective in controlling bleeding. However, minimizing radiation exposure is crucial, especially during organogenesis. Tailored interventions are essential to optimize outcomes in this unique patient population.

Angiomyolipomatous Lesions of the Nasal Cavity (Sinonasal Angioleiomyoma with Adipocytic Differentiation): A Multi-Institutional Immunohistochemical and Molecular Study.

Mesenchymal neoplasms composed of vascular, smooth muscle, and adipocytic components are uncommon in the nasal cavity. While angioleiomyoma (AL) is a smooth muscle tumor in the Head & Neck WHO classification, it is considered of pericytic origin in the Skin as well as Soft Tissue and Bone classifications. For nasal AL with an adipocytic component, the terms AL with adipocytic differentiation and angiomyolipoma (AML) have been applied, among others. AML is a type of perivascular epithelioid cell tumor (PEComa), most often arising in the kidney, sometimes associated with the tuberous sclerosis complex (TSC). It is uncertain whether nasal cavity AML and AL are best considered hamartomas or neoplasms, as their genetics are largely unexplored. We performed a multi-institutional retrospective study of nasal cavity mesenchymal lesions. Patient demographics, clinical histories, and histologic and immunohistochemical findings were collected. DNA and RNA were extracted from formalin-fixed, paraffin-embedded tissue and analyzed by SNP-based chromosomal microarray, targeted RNA fusion sequencing, and whole-exome sequencing. Fifteen lesions (3-42mm) were identified, predominantly in male (87%) patients with a median age of 60. Patients typically presented with obstructive symptoms, and none had a history of TSC. One AL was a recurrence from six years prior; 11 cases showed no recurrence (median 4.7 years, range: 0.88-12.4). Morphologically, 11 AML contained 30-80% smooth muscle, 10-25% vasculature, and 2-60% adipose tissue, while four AL contained 70-80% smooth muscle and 20-30% vasculature. Other histologic observations included ulceration, thrombosis, inflammation, myxoid change, senescent nuclei, and extramedullary hematopoiesis; no well-developed epithelioid cell morphology was identified. Immunohistochemically, all cases were positive for smooth muscle markers (actin, desmin, and/or caldesmon) and negative for melanocytic markers. Molecular analysis revealed loss of 3p and 11q in a single AML. No other known pathogenic copy number or molecular alterations were seen, including in TSC1/2, TFE3, or NOTCH2. Nasal cavity AML lacks morphologic, immunophenotypic, and genetic features of PEComa family AML. The significant histologic overlap between nasal AML and AL without distinguishing molecular features in either entity suggests "sinonasal angioleiomyoma with adipocytic differentiation" may be the most appropriate terminology for hybrid vascular and smooth muscle lesions containing adipocytic components.

Is fat quantification based on proton density fat fraction useful for differentiating renal tumor types?

This study retrospectively assessed the diagnostic accuracy of fat quantification based on proton density fat fraction (PDFF) for differentiating renal tumors. In this retrospective study, 98 histologically confirmed clear cell renal cell carcinomas (ccRCCs), 35 papillary renal cell carcinomas (pRCCs), 14 renal oncocytomas, 16 chromophobe renal cell carcinomas (chRCCs), 10 lymphomas, 19 uroepithelial tumors, 10 lipid-poor angiomyolipomas (AMLs), and 25 lipid-rich AMLs were identified in 226 patients (127 males and 99 females) over 5years. All patients underwent multiparametric kidney MRI. The MRI protocol included an axial plane and a volumetric 3D fat fraction sequence known as mDIXON-Quant for PDFF measurement. Demographic data were recorded, and PDFF values were independently reviewed by two radiologists blinded to pathologic results. MRI examinations were performed using a 1.5T system. MRI-PDFF measurements were obtained from the solid parts of all renal tumors. Fat quantification was performed using a standard region of interest for each tumor, compared to histopathological diagnoses. Sensitivity and specificity analyses were performed to calculate the diagnostic accuracy for each histopathological tumor type. Nonparametric variables were compared among the subgroups using the Kruskal-Wallis H test and Mann Whitney U test. P-values < 0.05 were considered statistically significant. In all, 102 patients underwent partial nephrectomy, 70 patients underwent radical nephrectomy, and the remaining 54 had biopsies. Patient age (mean: 58.11years; range: 18-87years) and tumor size (mean: 29.5mm; range: 14-147mm) did not significantly differ across groups. All measurements exhibited good interobserver agreement. The mean ccRCC MRI-PDFF was 12.6 ± 5.06% (range: 11.58-13.61%), the mean pRCC MRI-PDFF was 2.72 ± 2.42% (range: 2.12-3.32%), and the mean chRCC MRI-PDFF was 1.8 ± 1.4% (range: 1.09-2.5%). Clear cell RCCs presented a significantly higher fat ratio than other RCC types, uroepithelial tumors, lymphomas, and lipid-poor AMLs (p < 0.05). Lipid-rich AMLs demonstrated a very high fat ratio. MRI-PDFF facilitated accurate differentiation of ccRCCs from other renal tumors with high sensitivity and specificity.

Development and internal validation of a clinical risk score to predict incident renal and pulmonary tumours in people with tuberous sclerosis complex

ObjectiveThis study aims to develop and internally validate a clinical risk score to predict incident renal angiomyolipoma (AML) and pulmonary lymphangioleiomyomatosis (LAM) in people with tuberous sclerosis complex (TSC).Study designData...

Utility of Ultrasound-Guided Attenuation Parameter (UGAP) in Renal Angiomyolipoma (AML): First Results.

Angiomyolipoma (AML) are the most common benign solid renal mass. Differentiation from malignant tumours is essential. Imaging features in ultrasound may overlap between malignant lesions, especially between renal cell carcinoma (RCC) and AML. So far, sectional imaging has been necessary for reliable differentiation. The aim of this study is to evaluate the use of the ultrasound-guided attenuation parameter (UGAP), a recently established tool for assessing hepatic steatosis, in the differentiation of AMLs from other renal masses. Therefore, 27 patients with unknown solid renal masses were examined by ultrasound including UGAP. The attenuation was assessed qualitatively by attenuation map and quantitatively in comparison to the surrounding renal tissue. UGAP was applicable in 26/27 patients. Findings were compared with CT/MRI as the current imaging standard. A total of 18 AML and 9 other renal tumours were found. The diagnostic performance of B-Mode (hyperechogenic lesion) ultrasound was 77.8% in identifying AML. The diagnostic performance of the attenuation map showed a diagnostic performance of 92.6%, whereby UGAP measurements were successful in 76.9% of cases. Quantitatively, we found a significant difference (p < 0.034) in mean measured attenuation between AML (0.764 ± 0.162 dB/cm/MHz) vs. other renal tumours (0.658 ± 0.155 dB/cm/MHz). The best performance was found by a combined parameter of a hyperechogenic lesion with a positive attenuation map with an accuracy of 95.0%. In conclusion, UGAP may represent a possibility for differentiating solid renal lesions more accurately by ultrasound, especially classic hyperechoic AMLs from other renal lesions. Further studies are needed to increase the diagnostic reliability further.

Angiomyolipomatous Lesions of the Nasal Cavity (Sinonasal Angioleiomyoma with Adipocytic Differentiation): A Multi-Institutional Immunohistochemical and Molecular Study.

Mesenchymal neoplasms composed of vascular, smooth muscle, and adipocytic components are uncommon in the nasal cavity. While angioleiomyoma (AL) is a smooth muscle tumor in the Head & Neck WHO classification, it is considered of pericytic origin in the Skin as well as Soft Tissue and Bone classifications. For nasal AL with an adipocytic component, the terms AL with adipocytic differentiation and angiomyolipoma (AML) have been applied, among others. AML is a type of perivascular epithelioid cell tumor (PEComa), most often arising in the kidney, sometimes associated with the tuberous sclerosis complex (TSC). It is uncertain whether nasal cavity AML and AL are best considered hamartomas or neoplasms, as their genetics are largely unexplored. We performed a multi-institutional retrospective study of nasal cavity mesenchymal lesions. Patient demographics, clinical histories, and histologic and immunohistochemical findings were collected. DNA and RNA were extracted from formalin-fixed, paraffin-embedded tissue and analyzed by SNP-based chromosomal microarray, targeted RNA fusion sequencing, and whole-exome sequencing. Fifteen lesions (3 to 42 mm) were identified predominantly in male (87%) patients with a median age of 60. Patients typically presented with obstructive symptoms, and none had a history of TSC. One AL was a recurrence from six years prior; 11 cases showed no recurrence (median 4.7 years, range: 0.88-12.4). Morphologically, 11 AMLs contained 30-80% smooth muscle, 10-25% vasculature, and 2-60% adipose tissue, while four ALs contained 70-80% smooth muscle and 20-30% vasculature. Other histologic observations included surface ulceration, vascular thrombosis, chronic inflammation, and myxoid change; no well-developed epithelioid cell morphology was identified. Immunohistochemically, all cases were positive for smooth muscle markers (actin and/or desmin) and negative for melanocytic markers. Molecular analysis revealed loss of 3p and 11q in a single AML. No other known pathogenic copy number or molecular alterations were seen, including in TSC1/2, TFE3, or NOTCH2. Nasal cavity AML lacks morphologic, immunophenotypic, and genetic features of PEComa family AMLs. The significant histologic overlap between nasal AML and AL without distinguishing molecular features in either entity suggests "sinonasal angioleiomyoma with adipocytic differentiation" may be the most appropriate terminology for hybrid vascular and smooth muscle lesions containing adipocytic components.

Neoadjuvant everolimus in renal angiomyolipoma with or without tuberous sclerosis complex: Results from a multicenter, retrospective study.

To assess the efficacy and safety of preoperative neoadjuvant everolimus in renal angiomyolipomas (AML) patients with or without Tuberous Sclerosis Complex (TSC). This multi-institutional retrospective study enrolled renal AML patients who underwent partial nephrectomy (PN) or total nephrectomy after receiving at least 1 month of pre-operative everolimus. Imaging evaluations were collected before and after treatment, along with demographic, surgical, and follow-up information. The primary outcome was tumor volume reduction of ≥25%, with additional outcomes including recurrence, perioperative outcomes, renal function, and safety. From January 2015 to July 2022, 68 renal AML patients were studied-41 with TSC and 27 without. During everolimus treatment, 61.0% (25/41) of TSC patients and 44.4% (12/27) of non-TSC patients achieved tumor reduction of ≥25%. Additionally, 41.5% (17/41) of TSC patients and 18.5% (5/27) of non-TSC patients achieved a ≥ 50% reduction. Three TSC patients and 1 non-TSC patient discontinued treatment due to side-effects. Most patients (92.7% TSC, 85.2% non-TSC) underwent PN. After everolimus treatment, the necessary total nephrectomy decreased to 41.2% (7/17) from baseline. Postoperatively, 1 grade 3 and 3 grade 2 complications occurred, with no grade 4 or 5 complications. After a median follow-up of 24 months, only 1 TSC patient recurred with a diameter >3 cm. Retrospective nature is the major limitation of this study. Everolimus was effective and well-tolerated in neoadjuvant treatment for renal AML, especially in TSC patients. This neoadjuvant combination strategy of everolimus and PN could effectively controls recurrence and preserves renal function.

Growth kinetics and predictive factors in renal angiomyolipomas.

Although renal angiomyolipomas (AMLs) are benign lesions, they can grow and cause serious complications. In this study, we aimed to determine the factors affecting the growth of renal AMLs. Patients followed up for AMLs between January 2014 and January 2024 were screened. By accepting 2.5mm/year as the limit for a significant growth rate, the patients were divided into two groups: those with and without significant growth. Demographic characteristics, tumor characteristics, and laboratory parameters, platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), and aspartate aminotransferase-to-alanine aminotransferase (De Ritis) ratio, were compared between the groups. The study included a total of 98 patients. Of the entire cohort, 78.6% were women. Significant growth was detected in nine (9.2%) patients. Multivariate analysis revealed that the baseline scan tumor size, PLR, and De Ritis ratio were significant independent predictors of significant AML growth (p = 0.011, p = 0.017, and p = 0.030, respectively). In the receiver operating characteristic curve analysis, the cut-off value of PLR in predicting significant growth was 131.85 (sensitivity: 77.8%, specificity: 73%, area under the curve [AUC] 0754), while the cut-off value of the De Ritis ratio was 1.33 (sensitivity: 66.7%, specificity: 95.8%, AUC 0.721). Tumor size at the time of initial diagnosis, as well as PLR and De Ritis ratio, were found to be independent predictors of AML growth rate. The use of these factors in patient follow-up has the potential to assist clinicians in predicting tumor growth and related complications.

Renal epithelioid angiomyolipomas overexpress TFE3 and the TFE3-regulated gene TRIM63 in the absence of TFE3 rearrangement.

Angiomyolipoma (AML) is a neoplasm within the perivascular epithelioid cell tumor family that occurs somewhat frequently in the kidney. Most are indolent and discovered incidentally, with rare tumors demonstrating malignant clinical behavior. A small subset of renal AMLs withepithelioid features are associated with aggressive behavior, and may demonstrate morphologic overlap with renal cell carcinomas (e.g., clear cell renal cell carcinoma (RCC), TFE3-rearranged RCC). Prior studies of spindle cell and epithelioid AMLs have identified rare examples with underlying TFE3 gene fusions. TFE3 protein expression (demonstrated by immunohistochemistry) with no evidence of concurrent TFE3 rearrangements has been reported previously in 4/24 AMLs (17%) (Argani et al. Am J Surg Pathol 34:1395-1406, 2010). Currently, the relationship between TFE3 protein expression, TFE3 fusions, and expression of TFE3-mediated genes remains incompletely understood in renal epithelioid AMLs. We sought to explore these relationships using TFE3 break-apart fluorescence in situ hybridization (FISH) and TRIM63 RNA in situ hybridization (ISH) on epithelioid AMLs with moderate to strong TFE3 expression by immunohistochemistry. RNA sequencing (fusion panel) was performed on two cases with negative FISH results to assess for FISH-cryptic gene fusions. The series comprised five epithelioid AMLs from four patients (three women, one man) aged 13 to 76years. Allwere considered positive for TFE3by immunohistochemistry (2 + /3 + expression). TRIM63 ISH was performed on four specimens from three patients, yielding positive results in 3/3 tumors(100%) that were successfully analyzed. TFE3 break-apart FISH was performed on all samples, demonstrating a TFE3 rearrangement in only 1/4 tumors (25%). RNA sequencing demonstrated the absence of productive TFE3 gene fusions in three tumors with negative break-apart TFE3 FISH results. This study demonstrates that renal epithelioid AMLs overexpress TFE3 and TFE3-mediated genes (TRIM63) even in the absence of TFE3 rearrangements. This finding could be explained byfunctional upregulation of TFE3secondary to activation of themammalian target of rapamycin complex 1 (mTORC1). Expression of TFE3 and TRIM63 in this tumor type represents a potential pitfall, given the morphologic and immunophenotypic overlap between epithelioid AML and TFE3-alteredrenal cell carcinoma.

Transarterial embolization in Wunderlich syndrome due to recanalization of giant renal angiomyolipoma pseudoaneurysm: a case report and literature review

BackgroundAcute spontaneous bleeding from renal angiomyolipoma (AML) is one of the causes of Wunderlich syndrome, a rare and potentially fatal clinical condition. Clinical deterioration will occur if there is a delay in urgent management. There are several management options for renal angiomyolipoma rupture. However, until now little is known about the case of recanalization from post-coil embolization of renal angiomyolipoma. There is no guideline about embolization technique for the management of recurrent bleeding after embolization or coil recanalization of renal angiomyolipoma.Case presentationA 55-year-old male has Wunderlich syndrome caused by recurrent bleeding of giant AML of the left renal due to coil recanalization compounded by a pseudoaneurysm and other bleeding site in bilateral giant renal angiomyolipoma which is showed by contrast-enhanced abdominal computed tomography scan. The patient underwent urgent transarterial embolization and some blood transfusion. Clinical improvement occurred and the patient discharged several days later.ConclusionsEmbolization for spontaneous bleeding or rebleeding of renal pseudoaneurysms may become the first choice of treatment in bilateral multiple renal angiomyolipoma rather than other managements which are available to preserve renal function.

Contrast-Enhanced Ultrasound in the Diagnosis of Solid Renal Lesions.

The availability of imaging methods has enabled increased detection of kidney lesions, which are a common clinical problem. It is estimated that more than half of patients over the age of 50 have at least one undetermined mass in the kidney. The appropriate characterization and diagnosis of lesions imaged in the kidney allows for proper therapeutic management. Previously, contrast-enhanced computed tomography (CT) and contrast-enhanced magnetic resonance imaging (MRI) have been used in their extended diagnosis. However, the limitations of these techniques, such as radiation exposure, renal toxicity, and allergies to contrast agents, must be considered. Contrast-enhanced ultrasound (CEUS) is increasingly being used as an examination to resolve interpretive doubts that arise with other diagnostic methods. Indeed, it can be considered both as a problem-solving technique for diagnosing and distinguishing lesions and as a technique used for observation in preservative treatment. Evaluation of the enhancement curve over time on CEUS examination can help to differentiate malignant renal cell carcinoma (RCC) subtypes that should be resected from benign lesions, such as oncocytoma or angiomyolipoma (AML), in which surgery can be avoided. It allows for distinguishing between benign and malignant tumors, renal and pseudotumors, and solid and cystic tumors. Therefore, with recent advances in ultrasound technology, CEUS has emerged as a fast, reliable, and cost-effective imaging tool in the preoperative evaluation and diagnosis of solid renal masses.

A Life-threatening Case of Giant Bilateral Renal Angiomyolipoma: A Case Report

Renal angiomyolipoma (AML) is a rare tumor with an incidence of 0.3% - 3%. We reported a case of a 41-year-old male patient who presented with gross hematuria and hemorrhagic shock, due to a right giant angiomyolipoma he underwent urgent right nephrectomy by subcostal laparotomy, total weight of the mass was 6 Kg, histological examination concluded in a renal angiomyolipoma. Treatment of renal AML depends on the clinical presentation, tumor size, and single or multiple lesions: single small (&lt; 4 cm) asymptomatic lesions require only clinical and radiological follow-up, however giant symptomatic (hematuria), life-threatening masses require urgent multidisciplinary treatment and especially surgery. Giant renal bilateral AML is very rare, conservative treatment in the absence of hemorrhage should always be first proposed to preserve renal function as possible.

The extent of kidney involvement in paediatric tuberous sclerosis complex

BackgroundTuberous sclerosis (TSC)–associated kidney disease is a leading cause of mortality in adults with TSC. This study aimed to understand TSC features in children, particularly kidney involvement, to inform clinical care for this specific group.MethodsThis retrospective cohort study included all paediatric (< 19 years) TSC cases at a large tertiary paediatric nephrology centre. Relevant data were collected from patients’ records, statistical analyses were performed to identify associations between variables, survival probabilities were estimated with Kaplan‒Meier curves, and log-rank tests were conducted to assess survival differences among genetic mutations.ResultsA total of 182 children with TSC were included. Among the 145 children with available kidney imaging data, 78.6% (114/145) exhibited kidney lesions. Angiomyolipomas (AMLs) were significantly more prevalent in the TSC2 mutation group (p = 0.018). Children with TSC2 mutations generally had poorer lesion-free survival than those with TSC1 mutations, but this difference was only significant for AMLs (p = 0.030). The change in size of largest AMLs increased with age and doubled in children above 9 years; a similar pattern was observed when stratified by genetic mutation. In contrast, kidney cysts exhibited two peaks: one in children under 5 years (2.31 mm/year) and the second in children between 15–19 years (2.82 mm/year). Chronic kidney disease was observed in 12.3% (10/81) of children, and high-risk AMLs above 3 cm were observed in 9% (13/145).ConclusionsWhile TSC kidney disease emerges later in the disease course than neurological features, our findings emphasise the importance of kidney surveillance during childhood, including routine kidney imaging, kidney function, and blood pressure monitoring.Graphical abstract A higher resolution version of the Graphical abstract is available as Supplementary information

Comprehensive Insights Into Renal Perivascular Epithelioid Cell Neoplasms: From Molecular Mechanisms to Clinical Practice

Comprehensive Insights Into Renal Perivascular Epithelioid Cell Neoplasms: From Molecular Mechanisms to Clinical Practice

Safety and Efficacy of Cryotherapy for the Treatment of Renal Angiomyolipoma Related to Tuberous Sclerosis Complex: The Cryo-TSC Study

Purpose: Tuberous sclerosis complex (TSC) is a rare autosomal dominant inherited disease, in which approximately 60% to 80% of patients have bilateral angiomyolipoma (AML). There is a need for repeatable local treatments of TSC-AML. Cryotherapy is an option for renal tumors; however, its safety and efficacy for vascular tumors, such as TSC-AML, are unclear. The aim of this study was to establish the safety and efficacy of cryotherapy for TSC-AML. Materials and Methods: This was an open-label, single-arm, prospective phase II study to evaluate the safety and efficacy of cryotherapy for TSC-AML of ≤ 4 cm. Cryotherapy was performed using the CryoHit device with a percutaneous approach. Safety was assessed 1, 2, 6, and 9 months after cryotherapy, and efficacy was assessed 3 and 9 months after cryotherapy. The efficacy of cryotherapy was evaluated using the modified RECIST or RECIST criteria by independent central review. The primary end point was the disease control rate, and secondary end points were the overall response rate, safety, renal function, quality of life, and whether additional treatment was required. Results: The disease control rate was 100%, and the overall response rate was 93.3%. After 9 months of follow-up, the median estimated glomerular filtration rate decreased slightly (from 89.2 mL/min/1.73 m2 to 79.4 mL/min/1.73 m2). Quality of life was stable, and no additional treatment was needed. Three Grade 3 adverse events (hematuria, chronic kidney disease, and elevated aspartate aminotransferase) were observed in 3 patients, respectively, but no additional treatments were required. Conclusions: Cryotherapy for TSC-AML can be performed safely and efficiently. Cryotherapy can be a new therapeutic option for TSC-AML. Trial Registration Number: jRCTs072200039.

High-frame-rate contrast-enhanced ultrasound to differentiate between clear cell renal cell carcinoma and angiomyolipoma

BackgroundTo investigate the diagnostic efficacy of high-frame-rate contrast-enhanced ultrasound (H-CEUS) in differentiating between clear cell renal cell carcinoma (CCRCC) and angiomyolipoma (AML).MethodsA retrospective study was performed on the clinical data of 79 patients diagnosed with CCRCC and 31 patients diagnosed with AML at the First Affiliated Hospital of Nanchang University between October 2022 and December 2023. Conventional ultrasound (US) and H-CEUS examinations were conducted on all patients prior to surgery, dynamic images were recorded from the US, and the qualitative and quantitative parameters of H-CEUS were collected. The t-test, χ² test and non-parametric Mann-Whitney test were employed to assess differences in clinical data, US characteristics, and qualitative and quantitative parameters of H-CEUS between the CCRCC and AML groups. The independent risk factors of CCRCC were identified using binary logistic regression. The receiver operator characteristic (ROC) curve was constructed to evaluate the diagnostic effectiveness of clinical + US and H-CEUS in differentiating between CCRCC and AML.ResultsThe CCRCC group and the AML group exhibited significant differences in patient gender, operation mode, nodular echo, and nodule blood flow (χ²=11.698, -, -,=10.582; P<0.001, <0.001, <0.001, and = 0.014, respectively). In addition, the H-CEUS qualitative analysis demonstrated significant differences between the AML group and the CCRCC group with respect to enhancement mode, regression mode, peak intensity, enhancement uniformity, no enhancement, and presence or absence of pseudocapsule (χ²=41.614, -, -, = 2.758, = 42.099, -; P<0.001, <0.001, <0.001, 0.097, <0.001, and <0.001, respectively). The Arrival time (AT) in the CCRCC group was significantly shorter than that in the AML group, as determined by quantitative analysis of H-CEUS (Z=-3.266, P = 0.001). Furthermore, the Peak intensity (PI), Ascent slope (AS), and The area under the curve (AUC) exhibited significantly higher values in the CCRCC group compared to the AML group (Z=-2.043,=-2.545,=-3.565; P = 0.041, = 0.011, and <0.001, respectively). Logistic regression analysis indicated that only gender, nodule echo, the pseudocapsule, AS, and AUC of H-CEUS were independent risk factors of CCRCC. The ROC curve revealed that combining gender and nodule echo yielded a sensitivity of 92.4%, specificity of 64.5%, and an AUC of 0.847 in distinguishing between CCRCC and AML. When combining the H-CEUS parameters of pseudocapsule, AS, and AUC, the sensitivity, specificity, and AUC for distinguishing between CCRCC and AML were 84.8%, 96.8%, and 0.918, respectively. No statistically significant difference was observed in the diagnostic effectiveness of the two methods (Z=-1.286, P = 0.198). However, H-CEUS demonstrated better AUC and specificity.ConclusionsH-CEUS enhances the sensitivity and specificity of differentiating between CCRCC and AML by improving the temporal resolution, offering a more precise diagnostic foundation for identifying the most appropriate therapy for patients.

#2242 mTORi: edging closer to targeted therapy in tuberous sclerosis complex

Abstract Background and Aims Tuberous sclerosis complex (TSC) is an autosomal dominant condition with an estimated incidence of 1 in 6000 births. TSC is caused mostly by mutations in either TSC1 or TSC2 genes, with 70–80% of cases resulting from sporadic mutations; however in 10-15% of cases no mutations are identified. A dysregulation of these genes that encode the hamartin and tuberin proteins, respectively, results in an aberrant signaling of the mammalian target of the rapamycin (mTOR) pathway and subsequent tumor growth. Indeed, the clinical features of TSC are characterized by the proliferation of different types of hamartomas in various organs, including brain, heart, skin, lungs, eyes, bone, kidneys and less frequently pancreas. TSC is mainly diagnosed clinically according to diagnostic criteria with genetic testing performed in cases of diagnostic uncertainty or/and to support the clinic diagnosis. Renal angiomyolipomas (AMLs), observed in more than 80% of patients with TSC, are benign, mostly bilateral tumors, composed of immature smooth muscle cells, abnormal blood vessels and fat cells in variable portions. Their size and the prevalence of their vascular component are directly associated with risk of acute bleeding that in 25% of cases may require embolization or nephrectomy. As a consequence, renal complications are the leading cause of death in adult TSC patients and AML-related surgery is performed in a high percentage of these patients. In the last decade, mTOR inhibitor (mTOR-i) therapy has demonstrated to be a potential alternative to embolization and nephrectomy for managing TSC-AML. The aim of this study was to evaluate over time, potential changes in the relative tissue composition of renal AMLs and their overall size following the initiation of mTOR-i therapy based on MRI measurements. Method From August 2011 to May 2023, 86 potentially eligible adult TSC patients with AML, across a great part of Italy were referred for assessment and monitoring at our center. 14 of these patients were eligible for mTOR-i therapy. An ethics committee approved its use as a compassionate therapy as mTOR-is are not approved as a conventional therapy for renal AMLs in Italy. These patients underwent baseline renal magnetic resonance imaging (MRI) assessment and a regular follow-up with MRI scan every 6-9 months after initiation of therapy. Dose titration was guided by trough levels, side effects and lesion radiological responsiveness on MRI. Results No AML bleeding events were documented during the study. None of the 14 patients on treatment discontinued therapy. Overall, 5 of them (35.7%) required dose adjustments during the course of treatment due to adverse events (40%), sub-optimal trough levels (40%) or minimal radiological response (20%). Radiologic assessment with MRI confirmed a halted growth trend in all treatment-naive cases (100%) and in 64% of them, a regression in AML volume and a reduction of their vascular component within the first year of treatment. Conclusion Our experience confirmed results that emerged from different clinical studies evaluating mTOR inhibition in TSC patients conducted in the last decade. For renal angiomyolipoma, mTOR-i treatment, carefully monitored, fundamentally changed the approach from preventive embolization or even partial nephrectomy to pharmacological treatment; drastically limiting the number of urgent interventional procedures that TSC patients often might undergo. In conclusion, mTOR-i therapy represents a valid and important therapeutic strategy to arrest the growth or regress of renal AMLs.

Kidney transplantation in patients with tuberous sclerosis complex.

Tuberous sclerosis complex (TSC) is a disorder of the mammalian target of the rapamycin (mTOR) pathway associated with the development of multisystem tumors, including renal angiomyolipoma (AML). These renal tumors are benign by nature but locally invasive and carry a risk for the progression of chronic kidney disease (CKD) to end stage kidney disease (ESKD). The frequency of subsequent renal transplantation in this population is largely uncharacterized, although single-center data suggests that 5%-15% of adult TSC patients are kidney transplant recipients. This retrospective cohort study utilized United Network for Organ Sharing (UNOS) data. We included candidates waitlisted between 1987 and 2020 for a first kidney transplant with TSC-associated kidney failure. We utilized descriptive statistics to characterize the frequency of first-time kidney transplant waitlisting and transplantation among persons with TSC and the Fine-Gray subdistribution hazard model to evaluate characteristics associated with progression from waitlist. We identified 200 TSC-associated kidney failure patients within the waitlist cohort. Of these, 12 were pediatric patients. Two-thirds (N = 134) of waitlisted persons were female. One hundred forty patients received a transplant with a median waitlist time of 2 years. Younger age at waitlisting was associated with a greater probability of progressing to transplant (HR 0.98 [95% CI: 0.96-0.99]). 91.8% of kidney transplant recipients survived 1-year post-transplant with a functioning allograft. The majority of patients with TSC who are waitlisted for a kidney transplant progress onto transplantation with excellent 1-year post transplant patient and allograft survival.

Immunophenotypic analysis of angiomyolipoma with epithelial cysts, comparison to mixed epithelial and stromal tumors and epithelial and stromal elements of normal kidney and ovaries.

Angiomyolipoma with epithelial cysts (AMLEC) is a rare variant of renal angiomyolipoma (AML). It is characterized by a conventional AML component admixed with epithelial cysts within an "ovarian-like" stroma. Mixed epithelial and stromal tumor (MEST) is another renal neoplasm featuring epithelial cysts and "ovarian-like" stroma. While there is consensus that in MEST the epithelial and stromal components are neoplastic, in AMLEC it has been hypothesized that the epithelial component may represent renal tubular entrapment or ovarian-like transdifferentiation of tumor cells. The aim of this study was to compare the immunophenotypes of the epithelial-stromal components of AMLEC and MEST, with normal kidney and ovary to provide additional insights into the pathogenesis and relationships of these entities. In this study, we analyzed eight cases of AMLEC and 14 cases of MEST from 2003 to 2023. We used tissue microarrays, full sections, or unstained slides with an immunohistochemical panel including renal and ovarian markers: SF1, ER, PR, AR, PAX8, WT1, GATA3, CA-IX, p16, inhibin A, and BCL2. We compared these cases with ten non-neoplastic ovary and kidney samples. Our findings indicate that the epithelial component of AMLEC and MEST resembleshormone receptor positive renal tubular epithelium (AR + /ER - /PR -). AMLEC's stromal component resembled hormone receptor positive renal stroma, while MEST's resembled ovarian stroma, supporting mullerian transdifferentiation. Our study showed that the epithelial and stromal components of AMLEC and MEST are immunophenotypically different and also differ from normal tissues. Our findings suggest that in AMLEC, the epithelial-stromal component represents a hormonally driven proliferation of non-neoplastic renal elements within a dysregulated tumor microenvironment.