Magnetic resonance imaging and computed tomography characteristics of renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion

Clinical and pathological characteristics of renal cell carcinomas with MiTF translocation

INTRODUCTION

Microphthalmia Transfactor Family (MiTF) translocation renal cell carcinomas (RCCs) represent a rare subtype of renal cell cancers. They are diagnosed in young patients and have a poor prognosis. The aim of our study was to analyze the clinical and pathological features of patients with MiTF RCC.

MATERIAL AND METHOD

We performed a retrospective, monocentric, descriptive study including all patients operated for RCC between January 2015 and January 2023. The diagnosis of MiTF RCC was suspected by immunohistochemistry (IHC) and confirmed by fluorescent in situ hybridization (FISH). Survival data according to histological subtype (MiTF versus ccRCC) were analyzed using the Kaplan-Meier method and compared using a log-rank test. The primary endpoint was recurrence-free survival (RFS). A descriptive cohort analysis was performed.

RESULTS

Of the 960 patients included, 19 (2%) had FISH-confirmed MiTF tumors. The median age at diagnosis was 42 years [18-75], the sex ratio was 1.11 females for 1 male, and 4 (21%) patients were immediately metastatic. Median RFS was 21months for patients in the MiTF group and was significantly lower than that of ccRCC patients, HR=4.33 [CI95% 2.06; 9.10; P<0.001]. Of the 11 patients with cT1-T2 tumors, 9 (81.8%) were treated with nephron sparing-surgery, with 2 (22.2%) harbored local recurrence.

CONCLUSION

Our study shows that patients with MiTF translocation RCC have a significantly lower RFS than non-MiTF RCC patients. Nephron sparing surgery must be weighted by the high risk of recurrence in this particularly young population.

LEVEL OF EVIDENCE: 5

Multimodality imaging of Xp11.2 translocation/TFE3 gene fusion associated with renal cell carcinoma: a case report

Background

Xp11.2 translocation/TFE3 gene fusion associated with renal cell carcinoma (Xp11.2 RCC) exhibits unique biological characteristics and is associated with an increased incidence of tumor thrombosis, lymph node metastasis, and advanced disease stages. Multimodality imaging, including US, contrast-enhanced CT, multi-parametric MRI, and 18F-FDG PET/CT plays a crucial role in the preoperative diagnosis and differentiation of renal tumors.

Case report

A 15-year-old female presented with lumbar pain worsened, and developed persistent painless hematuria. The CT attenuation values of the scan without contrast, corticomedullary phase, nephrographic phase, and delayed phases were 35 HU, 83 HU, 82 HU, and 75 HU, respectively. The solid component of the mass displayed heterogeneous marked enhancement. Furthermore, MRU indicated that the lesion involved the cortical medulla and infringed on the renal sinus fat. The lesion appeared isosignal in T1WI, slightly low signal in T2WI, and slightly high signal in DWI. The degree of enhancement in the three phases of enhancement scan was lower than that in the renal parenchyma, and hemorrhage and necrosis were observed within the internal part of the lesion. To further clarify the staging, the patient underwent 18F-FDG PET/CT. PET/CT images showed multiple irregular occupancies in the right kidney with unclear borders, showing a heterogeneous increase in 18F-FDG uptake, with SUVmax values ranging from 2.3 to 5.2 in the routine imaging phase (60 min post-injection), compared to SUVmax values ranging from 2.8 to 6.9 in the delayed imaging phase (160 min post-injection). Additionally, multiple enlarged and fused lymph nodes were observed in the medial part of the right kidney and the retroperitoneum, exhibiting a heterogeneous increase in 18F-FDG uptake, with SUVmax values ranging from 4.1 to 8.7 in the routine imaging phase, compared to SUVmax values ranging from 4.4 to 9.1 in the delayed imaging phase. The postoperative pathology, immunohistochemistry, and molecular analysis of histiocytes were consistent with a diagnosis of Xp11.2 RCC. One month after surgery, enhanced-CT examination of the patient revealed lung metastasis, peritoneal metastasis, and multiple lymph node metastases throughout the body, with an overall survival of 16 months.

Conclusion

Xp11.2 RCC exhibits unique biological characteristics and is associated with an increased incidence of tumor thrombosis, lymph node metastasis, and advanced disease stages. Long-term follow-up is essential to monitor the likelihood of recurrence and metastasis. 18F-FDG PET/CT examination can comprehensively visualize the lesion's location and extent, providing a basis for clinical tumor staging and aiding in treatment monitoring and follow-up. To address the limitations of FDG, the utilization of specific tracers designed for RCC or tracers that are not excreted via the urinary system would be ideal. Further advancements in molecular imaging technologies and the development of novel tracers hold great promise in advancing the diagnosis and management of RCC, ultimately contributing to better patient outcomes and overall disease management.

Unravelling the mysteries of Xp11.2 translocation-associated renal cell carcinoma: A case report with a review of the literature

Cytomorphologic and immunocytochemical features of TFE3 translocation-associated renal cell carcinoma.

MRI Characteristics of Pediatric and Young-Adult Renal Cell Carcinoma: A Single-Center Retrospective Study and Literature Review

Pediatric renal cell carcinoma (RCC) is a rare malignancy. Magnetic resonance imaging (MRI) is the preferred imaging modality for assessment of these tumors. The previous literature has suggested that cross-sectional-imaging findings differ between RCC and other pediatric renal tumors and between RCC subtypes. However, studies focusing on MRI characteristics are limited. Therefore, this study aims to identify MRI characteristics of pediatric and young-adult RCC, through a single-center case series and literature review. Six identified diagnostic MRI scans were retrospectively assessed, and an extensive literature review was conducted. The included patients had a median age of 12 years (63-193 months). Among other subtypes, 2/6 (33%) were translocation-type RCC (MiT-RCC) and 2/6 (33%) were clear-cell RCC. Median tumor volume was 393 cm³ (29-2191 cm³). Five tumors had a hypo-intense appearance on T2-weighted imaging, whereas 4/6 were iso-intense on T1-weighted imaging. Four/six tumors showed well-defined margins. The median apparent diffusion coefficient (ADC) values ranged from 0.70 to 1.20 × 10^-3 mm²/s. In thirteen identified articles focusing on MRI characteristics of MiT-RCC, the majority of the patients also showed T2-weighted hypo-intensity. T1-weighted hyper-intensity, irregular growth pattern and limited diffusion-restriction were also often described. Discrimination of RCC subtypes and differentiation from other pediatric renal tumors based on MRI remains difficult. Nevertheless, T2-weighted hypo-intensity of the tumor seems a potential distinctive characteristic.

Contrast-Enhanced Ultrasound Features of Adult Xp11.2 Translocation Renal Cell Carcinoma: Differential Diagnosis With Three Main Renal Cell Carcinoma Subtypes

OBJECTIVES

To investigate the sonographic features in Xp11.2 translocation renal cell carcinoma (Xp11.2 tRCC) using both conventional ultrasound (US) and contrast-enhanced US (CEUS) and evaluate the usefulness of sonographic imaging characteristics to differentiate between Xp11.2 tRCC and the three common RCC subtypes.

METHODS

Thirty-four adult Xp11.2 tRCC patients who preoperatively underwent both conventional US and CEUS and had solitary renal lesions and pathological confirmation after surgery were enrolled. Control matched patients included 131 with clear cell RCC (ccRCC), 48 with papillary RCC (pRCC), and 35 with chromophobe RCC (chRCC). Conventional US and CEUS data of all patients were retrospectively analyzed and compared.

RESULTS

Xp11.2 tRCC was more common in young women. The echogenicity of Xp11.2 tRCC lesions was hypo- and isoechoic relative to the adjacent renal cortex. A higher frequency of calcification within tumors was detected in Xp11.2 tRCC, but the presence of color flow signal (26.5%, 9/34) was much lower. Regarding CEUS features relative to the adjacent renal cortex, synchronous wash-in (61.8%, 21/34), iso-enhancement at peak (55.9%, 19/34), and fast wash-out (50.0%, 17/34) were more common in Xp11.2 tRCC. Moreover, an integrated variables model based on these features could differentiate Xp11.2 tRCC from ccRCC, pRCC, and chRCC (area under the curve, sensitivity, and specificity: 0.934, 92.0%, and 86.0%; 0.907, 88.0%, and 87.0%; and 0.808, 65.0%, and 99.0%, respectively).

CONCLUSIONS

Combining conventional US and CEUS lesion features with clinical information may provide a feasible and effective method to differentiate Xp11.2 tRCC from ccRCC, pRCC, and chRCC.

Evaluation of radiomics and machine learning in identification of aggressive tumor features in renal cell carcinoma (RCC)

PURPOSE

The purpose of this study was to evaluate the use of CT radiomics features and machine learning analysis to identify aggressive tumor features, including high nuclear grade (NG) and sarcomatoid (sarc) features, in large renal cell carcinomas (RCCs).

METHODS

CT-based volumetric radiomics analysis was performed on non-contrast (NC) and portal venous (PV) phase multidetector computed tomography images of large (> 7 cm) untreated RCCs in 141 patients (46W/95M, mean age 60 years). Machine learning analysis was applied to the extracted radiomics data to evaluate for association with high NG (grade 3-4), with multichannel analysis for NG performed in a subset of patients (n = 80). A similar analysis was performed in a sarcomatoid rich cohort (n = 43, 31M/12F, mean age 63.7 years) using size-matched non-sarcomatoid controls (n = 49) for identification of sarcomatoid change.

RESULTS

The XG Boost Model performed best on the tested data. After manual and machine feature extraction, models consisted of 3, 7, 5, 10 radiomics features for NC sarc, PV sarc, NC NG and PV NG, respectively. The area under the receiver operating characteristic curve (AUC) for these models was 0.59, 0.65, 0.69 and 0.58 respectively. The multichannel NG model extracted 6 radiomic features using the feature selection strategy and showed an AUC of 0.67.

CONCLUSIONS

Statistically significant but weak associations between aggressive tumor features (high nuclear grade, sarcomatoid features) in large RCC were identified using 3D radiomics and machine learning analysis.

Factors Associated with Survival From Xp11.2 Translocation Renal Cell Carcinoma Diagnosis-A Systematic Review and Pooled Analysis

Purpose: Xp11.2 translocation renal cell carcinoma (Xp11.2 tRCC) is a rare subtype of renal cell carcinoma (RCC), characterized by translocations of Xp11.2 breakpoints, involving of the transcription factor three gene (TFE3). The aim of our study was to comprehensively characterize the clinical characteristics and outcomes, and to identify risk factors associated with OS and PFS in Xp11.2 tRCC patients.

Methods: Literature search on Xp11.2 tRCC was performed using databases such as pubmed EMBASE and Web of Science. Studies were eligible if outcomes data (OS and/or PFS) were reported for patients with a histopathologically confirmed Xp11.2 tRCC. PFS and OS were evaluated using the univariable and multivariable Cox regression model.

Results: There were 80 eligible publications, contributing 415 patients. In multivariable analyses, the T stage at presentation was significantly associated with PFS (HR: 3.87; 95% CI: 1.70 to 8.84; p = 0.001). The median time of PFS was 72 months. In the multivariable analyses, age at diagnosis (HR: 2.16; 95% CI: 1.03 to 4.50; p = 0.041), T stage at presentation (HR: 4.44; 95% CI: 2.16 to 9.09; p < 0.001) and metastasis status at presentation (HR: 2.67; 95% CI: 1.12 to 6.41; p = 0.027) were all associated with OS, with a median follow-up time of 198 months.

Conclusion: T stage at presentation is the only factor that is associated with both PFS and OS in patients with Xp11.2 tRCC. Also, patients over 45 or with metastases are more likely to have poorer OS.

Percutaneous radiofrequency ablation on a Xp11.2 Translocation Renal Cell Carcinoma: A case report

Xp11.2 Translocation Renal Cell Carcinoma is a very rare subtype of renal neoplasm. The present report describes the first confirmed reported case of percutaneous ablation of this subtype of tumor. The patient presented an aggressive local recurrence 12 months after the procedure, with an infiltrative large mass occupying almost the whole kidney. The patient was submitted to radical nephrectomy. As the use of ablative methods expands, the treatment of rare renal tumor subtypes, which can present unusual clinical outcomes, may become more frequent. It is essential that these uncommon outcomes are promptly recognized, allowing early therapeutic salvage approaches.

Radiomics and Artificial Intelligence for Renal Mass Characterization

Radiomics allows for high throughput extraction of quantitative data from images. This is an area of active research as groups try to capture and quantify imaging parameters and convert these into descriptive phenotypes of organs or tumors. Texture analysis is one radiomics tool that extracts information about heterogeneity within a given region of interest. This is used with or without associated machine learning classifiers or a deep learning approach is applied to similar types of data. These tools have shown utility in characterizing renal masses, renal cell carcinoma, and assessing response to targeted therapeutic agents in metastatic renal cell carcinoma.

Nephron-Sparing Surgery for Adult Xp11.2 Translocation Renal Cell Carcinoma at Clinical T1 Stage: A Multicenter Study in China

Purpose

To evaluate the oncologic efficacy and feasibility of nephron-sparing surgery (NSS) in adult Xp11.2 translocation renal cell carcinoma (RCC).

Patients and Methods

Seventy patients with Xp11.2 translocation RCC and 273 with conventional RCC from five institutions in Nanjing were retrospectively studied. All patients were older than 18 years and were categorized into clinical T1 (cT1) stage using preoperative imaging. Using the preoperative imaging and electronic medical records, anatomical and pathological features were collected and analyzed.

Results

Among patients with Xp11.2 translocation RCC, 18/36 (50.0%) with cT1a and 12/34 (35.3%) with cT1b tumors underwent NSS. The respective proportions in the conventional RCC group were 121/145 (83.4%) and 93/128 (72.7%). Among cT1a tumors, the Xp11.2 translocation RCCs tended to be adjacent to the collecting system, sinus, and axial renal midline compared with conventional RCCs. Patients with Xp11.2 translocation RCCs who underwent NSS had comparable progression-free survival (PFS) and overall survival to radical nephrectomy (RN) patients (P > 0.05). Among cT1b tumors, surgical margin positivity and pelvicalyceal, vascular, and region lymphatic involvement were more likely to occur in the Xp11.2 translocation RCCs (P < 0.05). Patients with Xp11.2 translocation RCC who underwent RN had a more favorable PFS than those who underwent NSS (P = 0.048). However, multivariate analysis of PFS did not identify surgical method as a risk factor (P = 0.089).

Conclusions

Among adults with Xp11.2 translocation RCC, NSS can be an alternative for patients with cT1a tumor but should be performed with more deliberation in patients with cT1b tumors.

Electronic supplementary material

The online version of this article (10.1245/s10434-020-08813-y) contains supplementary material, which is available to authorized users.

Characteristics and Outcome of Children with Renal Cell Carcinoma: A Narrative Review

Pediatric renal cell carcinoma (RCC) is a rare type of kidney cancer, most commonly occurring in teenagers and young adolescents. Few relatively large series of pediatric RCC have been reported. Knowledge of clinical characteristics, outcome and treatment strategies are often based on the more frequently occurring adult types of RCC. However, published pediatric data suggest that clinical, molecular and histological characteristics of pediatric RCC differ from adult RCC. This paper summarizes reported series consisting of ≥10 RCC pediatric patients in order to create an up-to-date overview of the clinical and histopathological characteristics, treatment and outcome of pediatric RCC patients.

[MiT family translocation renal cell carcinomas: Natural history, molecular features and multidisciplinary management]

MiT family translocation renal cell carcinomas (tRCC) represent a rare subtype of renal cell carcinomas. These tumors have been introduced for the first time in the World Health Classification (WHO) classification of kidney cancers in 2004. tRCC are characterized by reccurent translocations involving members of the MiT family transcription factors, mainly TFE3 and TFEB. The estimated incidence of these tumors is ∼1-5 % among all renal cell carcinomas, with female prodominance. tRCC were initially described in children, and the spectrum has been expanded over time to encompass adolescents and adults. TFE3- and TFEB-rearranged RCC harbor characteristic clinicopathological and immunohistochemical features and fluorescent hybridization in situ is considered the gold standard for their diagnosis, although it has some limitations especially when the partners are located in the vicinity of TFE3. Nephron-sparing surgery is an efficient treatment of localized cases when achievable. In metastatic setting, targeted agents and immunotherapy showed modest efficacy, with response rates and median overall survival inferior to those observed in clear-cell renal cell carcinomas. Management of tRCC necessite a multidisciplinary team and accrual in clinical trials have to be encouraged when possible. Novel biological insights are urgently awaited to better understand the mechanisms associated with kidney oncogenesis in this setting, and ultimately help to identify therapeutic targets.

Contrast-enhanced ultrasound findings of adult renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion: comparison with clear cell renal cell carcinoma and papillary renal cell carcinoma

BACKGROUND

To investigate the contrast-enhanced ultrasound (CEUS) findings of renal cell carcinoma (RCC) associated with Xp11.2 translocation/TFE3 gene fusion (Xp11.2/TFE3) in adult patients by comparison with those of clear cell RCC (ccRCC) and papillary RCC (pRCC).

METHODS

In total, 110 patients (110 renal masses) who underwent CEUS examinations were enrolled in this study. The cases included 18 Xp11.2/TFE3 RCCs, 60 ccRCCs and 32 pRCCs. All masses were confirmed by operative pathology. The CEUS imaging data of these patients were retrospectively analysed by two readers. The conventional US and CEUS features of Xp11.2/TFE3 RCC were compared with those of ccRCC and pRCC.

RESULTS

The age of the patients with Xp11.2/TFE3 RCC ranged from 20 to 68 years, with a mean age of 38.3 ± 16.3 years and a slight female predominance. The weighted kappa value that interprets the concordance between the interobserver agreement of the US and CEUS features ranged from 0.61 to 0.89. On conventional US and CEUS imaging of Xp11.2/TFE3 RCCs, the tumours were hypoechoic (6/18, 33.3%), isoechoic (8/18, 44.4%), and hyperechoic (4/18, 22.2%). The cystic component was present in 5 cases (27.8%), calcification was present in 9 cases (50.0%), and colour flow signal was present in 7 cases (38.9%). Most cases showed simultaneous wash-in (11/18, 61.1%); the peak enhancement showed hypoenhancement (6/18, 33.3%), isoenhancement (10/18, 55.6%), and hyperenhancement (2/18, 11.1%); most cases exhibited heterogeneous enhancement (12/18, 66.7%) and fast- or simultaneous-out (16/18, 88.9%); and a pseudocapsule was present in 6 cases (33.3%). In the multivariate logistic regression analysis, calcification and lower peak enhancement were more likely to be present in Xp11.2/TFE3 RCC than in ccRCC (P < 0.05), and younger age and relatively high peak enhancement were more likely to be present in Xp11.2/TFE3 RCC than in pRCC (P < 0.05). The calcification combined peak enhancement model differentiated Xp11.2/TFE3 RCC from ccRCC, and the age combined peak enhancement model differentiated Xp11.2/TFE3 RCC from pRCC with an AUC, a sensitivity and a specificity of 0.896, 94.4% and 73.3% and 0.786, 50.0% and 100.0%, respectively.

CONCLUSIONS

The specific CEUS features combined with demographic information and clinical symptoms may be helpful for differentiating Xp11.2/TFE3 RCC from ccRCC and pRCC.

Texture analysis of small renal cell carcinomas at MDCT for predicting relevant histologic and protein biomarkers

PURPOSE

To assess CT texture features of small renal cell carcinomas (≤ 4cm) for association with key pathologic features including protein biomarkers.

METHODS

Quantitative CT texture analysis (CTTA) of small renal cancers (≤ 4cm) was performed on non-contrast and portal venous phase abdominal MDCT scans with an ROI drawn at the largest cross-sectional diameter of the tumor using commercially available software. Texture parameters including mean pixel attenuation, the standard deviation (SD) of the pixel distribution histogram, entropy, the mean of positive pixels, the skewness (i.e., asymmetry) of the pixel histogram, kurtosis (i.e., peakness) of the pixel histogram, and the percentage of positive pixels were correlated with pathologic data from surgical resection, including histology and nuclear grade, as well as microarray analysis in a subset (n = 40) including Ki67 index, CRP, and neovascularization (CD105/CD31).

RESULTS

Portal venous phase images were available in 249 patients (105 women, 144 men; mean age, 56.7 years) with tumors ≤ 4cm (mean, median, range, ± SD; 2.66, 2.60, 0.3-4.0 ± 0.85 cm). CT texture features of standard deviation, mean of the positive pixels, and entropy of the pixel histogram were significantly associated with histologic cell type (clear vs. non-clear; p < 0.001). Entropy and mean of the positive pixels also showed an association with nuclear grade, although not statistically significant. In the microarray analysis subset, kurtosis of the pixel histogram was associated with CD105/CD31 (p = 0.05). SD also showed some association with CD 105 positivity (p = 0.02) and CAIX expression (p = 0.01). Non-contrast CT images were available in 174 patients (72 women, 102 men; mean age, 57.5 years). Although the association with histology was not as strong as on the portal venous phase, in the subset of patients with microarray data, SD was found to correlate with CRP (p = 0.08), kurtosis with CRP (p = 0.004), CD105/CD31 (p = 0.002), and with Ki 67 index (p < 0.001).

CONCLUSION

CT texture features were significantly associated with important histopathologic features in small renal cancers. These non-invasive measures can be performed retrospectively and may provide useful information when determining follow-up and treatment of small renal cancers.

Magnetic resonance imaging findings of renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion in adults: a pilot study

PURPOSE

The purpose of the study was to retrospectively analyze MRI findings of renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion (Xp11.2/TFE RCC) in adults.

METHODS

Sixteen patients with Xp11.2/TFE RCC were reviewed retrospectively. The clinical characteristics and imaging features were assessed and then compared between metastatic and non-metastatic subgroups.

RESULTS

The mean age at diagnosis was 47.4 (20-76) years. Seven (44 %) patients were men, and nine (56 %) patients were women. The lesions predominantly exhibited an endophytic distribution (n = 14, 88 %) with a capsule (n = 16, 100 %), accompanied by solid and cystic patterns (n = 12, 75%) and hemorrhage (n = 11, 69 %). The tumors prevalently appeared hyper- to isointense on T1WI (n = 14, 88 %), hypointense on T2WI (n = 13, 81 %), and hyperintense on DWI (n = 16, 100 %) with a lower ADC (P < 0.001) than that of the surrounding tissue. The tumors were less enhanced than the normal renal cortex in all phases with a prolonged enhancement pattern (P ≤ 0.001). In addition, six patients (38 %) developed recurrence or metastases. The RCCs with metastases showed an irregular shape (P = 0.013), an incomplete capsule (P = 0.018), heterogeneous solid-cystic patterns (P = 0.034), and hemorrhage (P = 0.037) than non-metastatic subgroups.

CONCLUSIONS

MRI provides valuable information for the diagnosis of adult Xp11.2/TFE RCCs. Features including irregular shape, incomplete capsule, mixed solid-cystic pattern, and hemorrhage may indicate the occurrence of recurrence or metastases.

Renal Tumors of Childhood: Radiologic-Pathologic Correlation Part 2. The 2nd Decade: From the Radiologic Pathology Archives

Malignant renal tumors account for 7% of childhood cancers, and Wilms tumors are by far the most common-but not in older children and adolescents. Among individuals in the latter half of their 2nd decade of life, renal cell carcinoma (RCC) is more common than Wilms tumor. The histopathologic spectrum of RCCs in children differs from that in adults. The most common subtype of RCC in children and adolescents is Xp11.2 translocation RCC, which is distinguished by hyperattenuation at nonenhanced computed tomography, a defined capsule, and associated retroperitoneal lymphadenopathy. Papillary RCC is the second most common histologic subtype. It enhances less intensely compared with the adjacent renal parenchyma and has a propensity for calcification. Clear cell RCC is seen in patients with von Hippel-Lindau disease and is distinguished by its relatively hypervascular nature. Medullary carcinoma affects adolescents with the sickle cell trait and is characterized by an infiltrative growth pattern and extensive metastasis at presentation. Angiomyolipoma is seen in children with tuberous sclerosis complex and is often multifocal and hypervascular, with macroscopic fat. Metanephric tumors are central, circumscribed, and typically calcified. Lymphoma usually manifests as multifocal masses, but it may involve a solitary mass or infiltrative pattern. Extensive adenopathy and involvement of the gastrointestinal tract or other organs also may be seen. Primitive neuroectodermal tumor is an aggressive neoplasm that is typically quite large at diagnosis. Knowledge of the clinical, biologic, and histopathologic features of renal tumors in older children and adolescents and their effects on the imaging appearance can help the radiologist offer a useful preoperative differential diagnosis.

Ultrasonographic Findings of Renal Cell Carcinomas Associated with Xp11.2 Translocation/TFE3 Gene Fusion

Objective

This study was to investigate the features of renal carcinomas associated with Xp11.2 translocations/TFE3 gene fusions (Xp11.2-RCC) on conventional ultrasound (US) and contrast-enhanced ultrasound (CEUS).

Methods

US and CEUS features of twenty-two cases with histopathologically proven Xp11.2-RCC were retrospectively reviewed.

Results

22 patients (11 males, 11 females) were included in this study, with a mean age of 28.3 ± 20.4 years. Eight tumors (36.3%, 8/22) were in left kidney, and 14 tumors (63.7%, 14/22) were in right kidney. All tumors (100%, 22/22) were mixed echogenicity type. 13 tumors (59.1%, 13/22) presented small dotted calcifications. The boundary of 14 tumors (63.6%, 14/22) was sharp and the other 8 tumors' (36.4%, 8/22) boundary was blurry. By CEUS, in early phase, the solid element of all tumors showed obvious enhancement. In delayed phase, 13 tumors showed hypoenhancement, seven tumors showed isoenhancement, and 2 tumors showed hyperenhancement. There were irregular nonenhancement areas in all tumors inside.

Conclusions

By US and CEUS, when children and adolescents were found to have hyperechoic mixed tumor in kidney with sharp margin and calcification, and the tumors showed obvious enhancement and hypoenhancement with irregular nonenhancement areas in the tumor in early phase and delayed phase, respectively, Xp11.2-RCC should be suspected.

Xp11.2 translocation renal cell carcinoma with TFE3 gene fusion: A case report

Xp11.2 translocation renal cell carcinoma (RCC) with transcription factor E3 (TFE3) gene fusion is a rare tumor, and the prognosis of this tumor is poorer compared with that of other subtypes of RCC. The patient presented herein was a 70-year-old man who presented with a solid mass sized ~8.2×6.1 cm in the right kidney and underwent radical right nephrectomy. Following pathological and immunohistochemical (IHC) examination and fluorescent in situ hybridization (FISH), the patient was diagnosed with Xp11.2 translocation RCC with TFE3 gene fusion. These tumors are more commonly encountered in children rather than in adults, and adult Xp11.2 translocation RCC is associated with a poorer prognosis compared with its pediatric counterpart. IHC assay and FISH are important diagnostic methods. However, there is currently no established effective treatment for Xp11.2 RCC.

Modified dixon-based renal dynamic contrast-enhanced MRI facilitates automated registration and perfusion analysis

Purpose

Renal dynamic contrast‐enhanced (DCE) MRI provides information on renal perfusion and filtration. However, clinical implementation is hampered by challenges in postprocessing as a result of misalignment of the kidneys due to respiration. We propose to perform automated image registration using the fat‐only images derived from a modified Dixon reconstruction of a dual‐echo acquisition because these provide consistent contrast over the dynamic series.

Methods

DCE data of 10 hypertensive patients was used. Dual‐echo images were acquired at 1.5 T with temporal resolution of 3.9 s during contrast agent injection. Dixon fat, water, and in‐phase and opposed‐phase (OP) images were reconstructed. Postprocessing was automated. Registration was performed both to fat images and OP images for comparison. Perfusion and filtration values were extracted from a two‐compartment model fit.

Results

Automatic registration to fat images performed better than automatic registration to OP images with visible contrast enhancement. Median vertical misalignment of the kidneys was 14 mm prior to registration, compared to 3 mm and 5 mm with registration to fat images and OP images, respectively (P = 0.03). Mean perfusion values and MR‐based glomerular filtration rates (GFR) were 233 ± 64 mL/100 mL/min and 60 ± 36 mL/minute, respectively, based on fat‐registered images. MR‐based GFR correlated with creatinine‐based GFR (P = 0.04) for fat‐registered images. For unregistered and OP‐registered images, this correlation was not significant.

Conclusion

Absence of contrast changes on Dixon fat images improves registration in renal DCE MRI and enables automated postprocessing, resulting in a more accurate estimation of GFR. Magn Reson Med 80:66–76, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

Clinical characteristics of XP11.2 translocation/TFE3 gene fusion renal cell carcinoma: a systematic review and meta-analysis of observational studies

Background

Renal cell carcinoma (RCC) associated with Xp11.2 translocation/TFE3 gene fusion (Xp11.2 RCC) is a rare subtype of RCC which is firstly described as a distinct entity in 2004 so that clinical characteristics of Xp11.2 RCC in different gender and age are unknown. The purpose of systematic review and meta-analysis is to provide a comprehensive assessment on them.

Methods

MEDLINE, EMBASE and Cochrane databases were searched for studies which evaluate the clinical characteristics of Xp11.2 RCC. The literature published between July 2004 and May 2014 was searched.

Results

A total of 15 studies with 147 participants were included. The meta-analysis demonstrated that number of patients of all age in female was higher than in male with pooled OR of 3.93(95 % CI = 1.66–9.34). However, incidence of distant metastases (OR = 0.34, 95 % CI = 0.12–1.57) and lymphatic metastases (OR = 0.51, 95 % CI = 0.14–1.91), tumor stage (OR = 0.85, 95 % CI = 0.34–2.15) and overall survival (OS) (OR = 0.46, 95 % CI = 0.05–4.34) between male and female were comparable. Incidence in female was higher than in male with pooled OR of 5.13(95 % CI = 1.67–15.72) in adults, while in children no gender-related predominance (OR = 1.19, 95 % CI = 0.38–3.72) was observed. In addition, incidence of distant metastases (OR = 1.00, 95 % CI = 0.13–7.84) and lymphatic metastases (OR = 1.00, 95 % CI = 0.07–13.67) and tumor stage (OR = 1.94, 95 % CI = 0.20–19.03) between children and adults were comparable. Survival curves presented comparable outcomes between male and female (P = 0.707) as well as between children and adults (P = 0.383).

Conclusions

Female patients with Xp11.2 RCC in adults exhibit a high incidence compared to male, but not in children. Comparable clinical characteristics including incidence of distant and lymphatic metastases, tumor stage and prognosis is presented between male and female as well as between children and adults.

CT Textural Analysis of Large Primary Renal Cell Carcinomas: Pretreatment Tumor Heterogeneity Correlates With Histologic Findings and Clinical Outcomes

OBJECTIVE

The purpose of the present study is to determine whether CT texture features of newly diagnosed primary renal cell carcinomas (RCCs) correlate with pathologic features and oncologic outcomes.

MATERIALS AND METHODS

CT texture analysis was performed on large (> 7 cm; mean size, 9.9 cm) untreated RCCs in 157 patients (52 women and 105 men; mean age, 60.3 years). Measures of tumor heterogeneity, including entropy, kurtosis, skewness, mean, mean of positive pixels, and SD of pixel distribution histogram were derived from multiphasic CT using various filter settings: unfiltered (spatial scaling factor, 0), fine (spatial scaling factor, 2), medium (spatial scaling factor, 3-4), or coarse (spatial scaling factor, 5-6). Texture values were correlated with histologic subtype, nuclear grade, pathologic stage, and clinical outcome.

RESULTS

When a coarse filter setting (spatial scaling factor, 6) was used, entropy on portal venous phase CT images was positively associated with clear cell histologic findings (odds ratio [OR], 134; 95% CI, 16-1110; p < 0.001) and was negatively associated with non-clear cell subtype findings (papillary spatial scale factor, 6; OR, 0.016; 95% CI, 0.002-0.132; p < 0.001). ROC curve analysis for entropy (on portal venous phase images obtained with a spatial scaling factor of 6) revealed an AUC of 0.943 (95% CI, 0.892-0.993) for clear cell histologic findings, with similar values noted for non-clear cell histologic findings. The mean of positive pixels and the SD of the pixel distribution histogram were statistically significantly associated with histologic cell type in a similar fashion. Entropy, the SD of the pixel distribution histogram, and the mean of positive pixels were associated with nuclear grade, most prominently when fine or medium texture filters were used (p < 0.05). There was a statistically significant association of texture features noted on unenhanced CT, including the SD of the pixel distribution histogram, the mean of positive pixels, and entropy, with the time to disease recurrence and death due to disease (e.g., for entropy noted on unenhanced CT images obtained with a spatial scaling factor of 6, the hazard ratio was 3.49 [95% CI, 1.55-7.84]; p = 0.002).

CONCLUSION

CT texture features (in particular, entropy, the mean of positive pixels, and the SD of the pixel distribution histogram) are associated with tumor histologic findings, nuclear grade, and outcome measures. The contrast phase does seem to affect heterogeneity measures.

Dynamic Computed Tomographic Features of Adult Renal Cell Carcinoma Associated With Xp11.2 Translocation/TFE3 Gene Fusions: Comparison With Clear Cell Renal Cell Carcinoma

OBJECTIVE

To investigate the dynamic contrast-enhanced computed tomography (CT) characteristics of renal cell carcinoma associated with Xp11.2 translocation and TFE gene fusion (Xp11.2 RCC) by comparison with clear cell renal cell carcinoma (CCRCC).

METHODS

Dynamic contrast-enhanced CT images and clinical and pathological records of 20 adult patients with Xp11.2 RCC confirmed by TFE3 immunohistochemical and fluorescence in situ hybridization assay were retrospectively analyzed and compared with the findings of 21 contemporary CCRCCs.

RESULTS

Renal cell carcinoma associated with Xp11.2 translocation and TFE gene fusions often occurred in young (30.6 ± 8.6 years) patients with hematuria (9/20). They presented as well-defined (17/20) cystic-solid (17/20) mass with hemorrhage (8/20) and circular/rim calcifications (6/20). Dynamic contrast-enhanced CT showed heterogeneous moderate prolonged enhancement. A tumor-to-cortex attenuation ratio in corticomedullary phase less than 0.62 gave a sensitivity of 90.0% and a specificity of 92.9% in differentiating Xp11.2 RCC from CCRCC (area under the receiver operating characteristic curve = 0.957, P < 0.001).

CONCLUSIONS

Computed tomographic characteristics and dynamic contrast-enhanced patterns and index can differentiate Xp11.2 RCC from CCRCC.

Renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusions: clinical experience and literature review

Aim: To analyze the clinicopathological features of renal cell carcinoma (RCC) associated with Xp11.2 translocation/TFE3 gene fusions (Xp11.2 RCC) in our institution. Materials & methods: We screened 983 RCC specimens. TFE3 immunohistochemical staining and FISH assay confirmed 22 Xp11.2 RCCs out of 65 suspicious cases. Clinicopathological and treatment outcomes of 22 patients were retrospectively analyzed. Results: In total, 22 patients included 13 females and nine males with a mean age of 27 years. Ten patients showed gross hematuria. Treatments included surgeries, immunotherapy and molecular-targeted therapy. Seven cases were at stage III/IV and four cases had tumor thrombosis or distant metastasis. During a median follow-up of 34 months, 19 patients were alive while three died of distant metastasis. Conclusion: Xp11.2 RCC is rare and FISH proved a useful diagnostic tool. Surgical resection achieved favorable outcome for early disease. Adult patients at advanced stage had poorer outcomes even with postoperative adjuvant therapy.

Dynamic Contrast-Enhanced CT Characterization of Xp11.2 Translocation/TFE3 Gene Fusions versus Papillary Renal Cell Carcinomas

PURPOSE

To compare the differences of CT characteristics between renal cell carcinomas (RCCs) associated with Xp11.2 translocation/TFE3 gene fusions (Xp11.2 RCCs) and papillary cell renal cell carcinomas (PRCCs).

METHODS

CT images and clinical records of 64 patients (25 Xp11.2 RCCs, 15 type 1 and 24 type 2 PRCCs) were analyzed and compared retrospectively.

RESULTS

Xp11.2 RCC more frequently affected young (30.7 ± 8.7 years) women (16/25, 64%) with gross hematuria (12/25, 48%), while PRCC more frequently involved middle-aged (54.8 ± 11.1 years) men (28/39, 71.8%) asymptomatically. Xp11.2 RCC tended to be heterogeneous density with some showing circular calcification. Lesion sizes of Xp11.2 RCC (5.4 ± 2.2 cm) and type 2 PRCC (5.7 ± 2.5 cm) were significantly larger than that of type 1 PRCC (3.8 ± 1.8 cm). Xp11.2 RCC contained more cystic components (22/25, 88%) than type 1 PRCC (all solid) and type 2 PRCC (9/24, 36.0%). Type 1 PRCC (13/15, 86.7%) and Xp11.2 RCC (21/25, 84.0%) showed more clear boundary than type 2 PRCC (12/24, 50.0%).

CONCLUSION

CT features including diameter, boundary, attenuation, nature, and circular calcification of the tumor, combined with demographic information and symptoms, may be useful to differentiate Xp11.2 RCC from different subtypes of PRCC.

Xp11.2 translocation renal cell carcinoma with egg-shell calcification mimicking a benign renal tumour: A case report

The present study reports the case of a 20-year-old female who was identified to have a left renal angiomyolipoma (AML) with hemorrhage. Following temporary conservative observation, the patient received continuous ultrasonic follow-up. Due to the rapid growth of the lesion, further examinations were performed. Computed tomography (CT) plain scans revealed a partly high-density mass with marginal egg-shell calcification. Enhanced CT revealed a solid tumor with a rich blood supply. Since no fats were detected, the possibility of a typical AML was excluded, but the diagnoses of epithelioid AML or renal cancer were considered. Finally, the left kidney was partially excised laparoscopically. The intraoperative frozen section indicated a diagnosis of renal cell carcinoma (RCC). The left kidney was subsequently radically excised. Routine histopathological and immunohistochemical tests confirmed that the lesion was an RCC with an Xp11.2 translocation. The present study introduces the pitfalls in the diagnosis of Xp11.2 translocation RCC, which is a rare RCC subtype accompanied with uncommon imaging manifestations. The study suggests that when a rapidly-growing AML is detected by ultrasound, renal cancer with marginal calcification should be considered. Moreover, although egg-shell calcification mostly occurs in benign renal lesions, further examinations, such as enhanced CT, are recommended for identifying the nature of the masses and excluding the possibility of malignant tumors.

Renal cell carcinomas with t(6;11) (p21;q12): presentation of two cases with computed tomography findings

Renal cell carcinomas with t(6;11) (p21;q12) translocation are extremely rare and primarily affect children and young adults. To our knowledge, there has been no case report focusing on the imaging manifestations in the existing literature. Hence, we describe the computed tomography findings of two young adults.