ASD-Net: a novel U-Net based asymmetric spatial-channel convolution network for precise kidney and kidney tumor image segmentation

Early intervention in tumors can greatly improve human survival rates. With the development of deep learning technology, automatic image segmentation has taken a prominent role in the field of medical image analysis. Manually segmenting kidneys on CT images is a tedious task, and due to the diversity of these images and varying technical skills of professionals, segmentation results can be inconsistent. To address this problem, a novel ASD-Net network is proposed in this paper for kidney and kidney tumor segmentation tasks. First, the proposed network employs newly designed Adaptive Spatial-channel Convolution Optimization (ASCO) blocks to capture anisotropic information in the images. Then, other newly designed blocks, i.e., Dense Dilated Enhancement Convolution (DDEC) blocks, are utilized to enhance feature propagation and reuse it across the network, thereby improving its segmentation accuracy. To allow the network to segment complex and small kidney tumors more effectively, the Atrous Spatial Pyramid Pooling (ASPP) module is incorporated in its middle layer. With its generalized pyramid feature, this module enables the network to better capture and understand context information at various scales within the images. In addition to this, the concurrent spatial and channel squeeze & excitation (scSE) attention mechanism is adopted to better comprehend and manage context information in the images. Additional encoding layers are also added to the base (U-Net) and connected to the original encoding layer through skip connections. The resultant enhanced U-Net structure allows for better extraction and merging of high-level and low-level features, further boosting the network's ability to restore segmentation details. In addition, the combined Binary Cross Entropy (BCE)-Dice loss is utilized as the network's loss function. Experiments, conducted on the KiTS19 dataset, demonstrate that the proposed ASD-Net network outperforms the existing segmentation networks according to all evaluation metrics used, except for recall in the case of kidney tumor segmentation, where it takes the second place after Attention-UNet.

The effect of 11th rib excision on perioperative outcomes in patients undergoing partial nephrectomy for upper pole renal tumors

INTRODUCTION

We aimed to evaluate the effect of eleven11th rib resection.on the perioperative period TRIFECTA criteria in patients who underwent retroperitoneal partial nephrectomy (PN) with the diagnosis of upper pole kidney tumors.

MATERIALS AND METHODS

We conducted a retrospective analysis of the data of the patients who underwent Open PN for upper pole renal masses between 2018 and 2023. The patients were divided into two groups: PN with rib resection and PN without rib resection. The demographic characteristics, tumor sizes, PADUA scores, warm-cold renal ischemia times, mass excision and tumor bed suturing times, histopathological tumor type and surgical margin positivity of the patients were examined. Both groups were evaluated comparatively based on this data.

RESULTS

The renal nephrometry scores of the two groups were similar. The total renal ischemia time was significantly shorter in the patients who underwent a rib resection than in those who did not (p < 0.001). Both the tumor excision and tumor bed suturing times were significantly shorter in the group that underwent a rib resection than in the group that did not (p < 0.001). The Clavien-Dindo complication grades were statistically similar between the two groups.

CONCLUSION

Complex in nature and high-risk renal masses located in the upper pole of the kidney, partial nephrectomy performed with an 11th rib resection can be considered a reliable surgical option with a shorter ischemia time, supporting the preservation of long-term renal function.

Kidney Tumor Classification on CT images using Self-supervised Learning

One of the most common diseases affecting society around the world is kidney tumor. The risk of kidney disease increases due to reasons such as consumption of ready-made food and bad habits. Early diagnosis of kidney tumors is essential for effective treatment, reducing side effects, and reducing the number of deaths. With the development of computer-aided diagnostic methods, the need for accurate renal tumor classification is also increasing. Because traditional methods based on manual detection are time-consuming, boring, and costly, high-accuracy tests can be performed faster and at a lower cost with deep learning (DL) methods in kidney tumor detection (KTD). Among the current challenges regarding artificial intelligence-assisted KTD, obtaining more precise programming information and the capacity to group with high accuracy make clinical determination more vital and bring it to an important point for current treatment in KTD prediction. This encourages us to propose a more effective DL model that can effectively assist specialist physicians in the diagnosis of kidney tumors. In this way, the workload of radiologists can be alleviated and errors in clinical diagnoses that may occur due to the complex structure of the kidney can be prevented. A large amount of data is needed during the training of the developed methods. Although various studies have been conducted to reduce the amount of data with feature selection techniques, these techniques provide little improvement in the classification accuracy rate. In this paper, a masked autoencoder (MAE) is proposed for KTD, which can produce effective results on datasets containing some samples and can be directly fine-tuned and pre-trained. Self-supervised learning (SSL) is achieved through self-distillation (SD), which can be reintroduced into the configuration loss calculation using masked patches. The SD loss on the decoder and encoder outputs' latent representation is calculated operating SSLSD-KTD. The encoder obtains local attention, while the decoder transfers its global attention to calculate losses. The SSLSD-KTD method reached 98.04 % classification accuracy on the KAUH-kidney dataset, including 8400 samples, and 82.14 % on the CT-kidney dataset, containing 840 samples. By adding more external information to the SSLSD-KTD method with transfer learning, accuracy results of 99.82 % and 95.24 % were obtained on the same datasets. Experimental results have shown that the SSLSD-KTD method can effectively extract kidney tumor features with limited data and can be an aid or even an alternative for radiologists in decision-making in the diagnosis of the disease.

Ewing's sarcoma of kidney extending into IVC and RA: resection using modified cannulation strategy for CPB

Ewing's sarcoma of the kidney is a rare tumor. Although renal carcinomas are known to involve the inferior cava, extension of the tumor up to the right atrium is not common. In the majority of cases when the tumor extends into the infrahepatic part of the inferior vena cava, it can be removed from the abdominal approach. Few patients require the use of cardiopulmonary bypass for removal of the tumor in the inferior vena cava and right atrium. The management of patients requiring resection of kidney tumors and right atrial mass is more complicated and requires a team approach consisting of oncosurgeons, cardiac surgeons, and cardiac anesthetists. The resection of the kidney tumor with a mass in the right atrium is usually done concomitantly. The cardiopulmonary bypass cannulation strategy needs to be modified in such cases.

Actual encounters of the kidney kind: Exploring 48 cases of renal collision tumors through the lens of literature

Multiple tumors of different lineages merging into a single mass, termed collision tumors, are considered a rare phenomenon in the kidney. Tumor components, or partners, may be malignant (including metastatic disease), borderline, or benign. We report the largest cohort to date of 48 cases. The cases were identified from the archives of three institutions in the last 16 years, including 43 (90%) with 2 tumor partners (dyad) and 5 (10%) with 3 partners (triad), totaling 101 individual neoplasms. The majority of cases involved immunohistochemical workup, and 5 underwent FISH or molecular studies. Forty (83%) cases featured a malignant entity, including all triads. Twenty dyads and two triads were composed entirely of malignant tumors. The most common malignant partner was clear cell renal cell carcinoma (RCC) (N = 19) followed by papillary RCC (N = 17). Nine (19%) cases featured borderline entities, including 5 multilocular cystic neoplasms of low malignant potential and 6 clear cell papillary renal cell tumors. Twenty one (44%) cases contained a benign partner, including 6 benign dyads. Papillary adenoma (N = 13) and oncocytoma (N = 8) were most common. Epithelial tumors were present in all 48 cases, and non-epithelial neoplasms in 9 cases (19%). Our cohort includes many novel combinations and collision partners with rare entities such as SDH-deficient RCC, TFE3-rearranged RCC, eosinophilic solid and cystic RCC, and acquired cystic disease associated RCC. A comprehensive literature review and analysis of collision tumor phenomenon in kidney placed these cases in context suggesting that collision tumors of the kidney are more common than previously recognized.

Exosomal long non-coding RNA MALAT1: a candidate of liquid biopsy in monitoring of Wilms' tumor

PURPOSE

Wilms' tumor (WT) is a rare kidney cancer that primarily affects children. Exosomes are extracellular vesicles that cargo nucleic acids, proteins,etc. for cellular communication. Long non-coding RNAs (lncRNAs) have utility as biomarkers for cancer diagnosis, prognosis, and disease monitoring. We hypothesize that expression of lncRNA, metastasis-associated lung adenocarcinoma transcript-1(MALAT1), is dysregulated and possibly trafficked within exosomes to influence the tissue microenvironment for metastasis and recurrence of WT.

METHODS

We investigated the expression of MALAT1 in thirty WT samples by qPCR. Exosomes were isolated using a precipitated and affinity-binding-based kit, and characterized using TEM, NTA, and DLS.

RESULTS

Mean number of exosomes was 9.01×108/mL in primary culture, 1.64×108/mL in urine, and 4.65×108/plasma:400µl. Average yield of total RNA was 1.28µg (primary-culture supernatant:1ml), 1.47µg (Urine:1ml), 1.65µg (Plasma:400 µL). We quantified MALAT1 in exosomes derived from these sources in patients of WT. Expression of MALAT1 was significantly downregulated (p=0.008) in WT samples.

CONCLUSION

This is the first study that demonstrated the presence of lncRNA MALAT1 in various invasive and non-invasive samples of patients with WT(primary tissue culture, urine, and plasma samples).

An etiological assessment of a deep vein thrombosis led to the discovery of a renal tumor collision: Case report

INTRODUCTION AND IMPORTANCE

The thromboembolic complication of kidney's tumor is rare, and they can be the reason for the discovery of those tumor. Also the collision kidney tumor, such as a simultaneous occurrence of different histological types of adjacent neoplasms in the same organ is rare.

CASE PRESENTATION

We report a patient diagnosed with a kidney tumor discovered in the context of an etiological assessment of thrombosis, presenting with pulmonary embolism and deep vein thrombosis of the lower limb. This tumor treated by a cytoreductive nephrectomy. The histologic diagnosis of PRCC (Papillary Renal Cell Carcinoma) associated with a chromophobe cell carcinoma and sarcomatoid component was rendered.

CLINICAL DISCUSSION

The development of the tumor process and its progression to the metastatic stage is largely favored by the hypercoagulable state, and the cancer itself promotes the appearance of thrombo-enmbolic phenomena due to this phenomenon. Two major studies recommend that immediate cytoreductive nephrectomy should be offered to metastatic patients with a good general condition.

CONCLUSION

A renal tumor collision is rare, whereas the risk factors for a renal tumor collision are the same as a renal tumor without collision, just as the management of a metastatic renal tumor is the same. Understanding the thromboembolic physiopathology in the case of kidney cancer has made it possible to optimize management.

Improving segmentation and detection of lesions in CT scans using intensity distribution supervision

We propose a method to incorporate the intensity information of a target lesion on CT scans in training segmentation and detection networks. We first build an intensity-based lesion probability (ILP) function from an intensity histogram of the target lesion. It is used to compute the probability of being the lesion for each voxel based on its intensity. Finally, the computed ILP map of each input CT scan is provided as additional supervision for network training, which aims to inform the network about possible lesion locations in terms of intensity values at no additional labeling cost. The method was applied to improve the segmentation of three different lesion types, namely, small bowel carcinoid tumor, kidney tumor, and lung nodule. The effectiveness of the proposed method on a detection task was also investigated. We observed improvements of 41.3% → 47.8%, 74.2% → 76.0%, and 26.4% → 32.7% in segmenting small bowel carcinoid tumor, kidney tumor, and lung nodule, respectively, in terms of per case Dice scores. An improvement of 64.6% → 75.5% was achieved in detecting kidney tumors in terms of average precision. The results of different usages of the ILP map and the effect of varied amount of training data are also presented.

Clinical Features and Prognostic Factors of Metastatic Non-Clear Cell Renal Cell Carcinoma: A Multicenter Study from the Turkish Oncology Group Kidney Cancer Consortium

INTRODUCTION

We aimed to evaluate clinical features, prognostic factors, and treatment preferences in patients with non-clear cell renal cell carcinoma (nccRCC).

METHODS

Patients with metastatic nccRCC were selected from the Turkish Oncology Group Kidney Cancer Consortium (TKCC) database. Clinical features, prognostic factors, and overall survival (OS) outcomes were investigated.

RESULTS

A total of 118 patients diagnosed with nccRCC were included in this study. The median age at diagnosis was 62 years (interquartile range: 56-69). Papillary (57.6%) and chromophobe tumors (12.7%) are common histologic subtypes. Sarcomatoid differentiation was present in 19.5% of all patients. When the patients were categorized according to the International Metastatic RCC Database Consortium (IMDC) risk scores, 66.9% of the patients were found to be in the intermediate or poor risk group. Approximately half of the patients (55.9%) received interferon in the first line. At the median follow-up of 53.2 months (95% confidence interval [CI]: 34.7-71.8), the median OS was 19.3 months (95% CI: 14.1-24.5). In multivariate analysis, lung metastasis (hazard ratio [HR]:2.22, 95% CI: 1.23-3.99) and IMDC risk score (HR: 2.35, 95% CI: 1.01-5.44 for intermediate risk; HR: 8.86, 95% CI: 3.47-22.61 for poor risk) were found to be independent prognostic factors.

CONCLUSION

In this study, survival outcomes are consistent with previous studies. The IMDC risk score and lung metastasis are the independent prognostic factors for OS. This is an area that needs research to better treat this group of patients and create new treatment options.

Cost-effectiveness of robotic-assisted surgery vs open surgery in the context of partial nephrectomy for small kidney tumors

To evaluate the cost-effectiveness of robotic-assisted surgery compared to open surgery in the context of partial nephrectomy for small kidney tumor management. This is a retrospective study using data from 395 patients operated on by either robot-assisted surgery (RAPN) or by open partial nephrectomy (OPN); one hospital performed RAPN exclusively and the second hospital, OPN exclusively. Cost-effectiveness analysis was conducted from the perspective of the National Health Insurance System (NHIS) by considering the costs of the initial hospital stay and the cost of complications. Clinical outcome was defined by the avoidance of major complications during the 12 months postoperatively. Major complications were absent in 82% of patients in the OPN group and 93% of patients in the RAPN group, with 11% in favor of robotic assistance (p < 0.001). The average cost per patient, including the costs of complications, were, respectively, 9637 € and 8305 € for the OPN and RAPN groups. Robotic assistance was associated with a 1332 € lower cost (p < 0.001). The incremental cost-effectiveness ratio (ICER) is estimated at - 12,039 €. From the perspective of the public payer, robotic assistance was associated with a lower rate of postoperative complications and a lower average cost per patient. Robotic-assisted surgery was an efficient alternative to open surgery in partial nephrectomy. Trial registration number: NCT05089006 (October 22, 2021).

Evaluation of prognostic factors and treatment options for renal angiosarcoma: A retrospective analysis of 113 reported cases

BACKGROUND

Primary renal angiosarcoma (PRA) is an extremely rare and aggressive neoplasm. Indeed, due to its rarity, established clinical guidelines for PRA have not yet been established. In this study, we attempted to investigate its prognostic factors and treatment options.

METHODS

We systematically searched for articles describing PRA that had been published up until December 2021. The final cohort included 113 patients in 103 articles. The starting point of this study was the time of diagnosis and the end point was the time of recurrence and disease-specific mortality.

RESULTS

Metastasis at diagnosis was associated with poorer disease-specific survival (DSS) (p = 0.001). Tumors of more than 5 cm had poorer DSS than tumors of 5 cm or less (p < 0.001). Multivariate analysis demonstrated that primary metastatic status, and tumor size were independent prognostic factors. In cases of localized PRA, tumor sizes exceeding 5 cm had also prognostic significance for recurrence-free survival (RFS) and DSS. Surgical margins, postoperative radiation, and postoperative systemic therapy were not associated with prognoses. However, in a subgroup analysis of tumors exceeding 5 cm, postoperative radiation therapy improved RFS and DSS (p = 0.022 and p = 0.031, respectively). In cases of metastatic PRA, systemic therapy improved DSS (p < 0.001).

CONCLUSION

We identified several prognostic factors for PRA. Among them, primary metastatic status and tumor size exceeding 5 cm were selected as independent prognostic factors. Postoperative radiation therapy for large, localized PRA and systemic therapy for recurrent and metastatic PRA might be a treatment option.

Intraoperative complications in kidney tumor surgery: critical grading for the European Association of Urology intraoperative adverse incident classification

INTRODUCTION

The European Association of Urology committee in 2020 suggested a new classification, intraoperative adverse incident classification (EAUiaiC), to grade intraoperative adverse events (IAE) in urology.

AIMS

We applied and validated EAUiaiC, for kidney tumor surgery.

PATIENTS AND METHODS

A retrospective multicenter study was conducted based on chart review. The study group comprised 749 radical nephrectomies (RN) and 531 partial nephrectomies (PN) performed in 12 hospitals in Finland during 2016-2017. All IAEs were centrally graded for EAUiaiC. The classification was adapted to kidney tumor surgery by the inclusion of global bleeding as a transfusion of ≥3 units of blood (Grade 2) or as ≥5 units (Grade 3), and also by the exclusion of preemptive conversions.

RESULTS

A total of 110 IAEs were recorded in 13.8% of patients undergoing RN, and 40 IAEs in 6.4% of patients with PN. Overall, bleeding injuries in major vessels, unspecified origin and parenchymal organs accounted for 29.3, 24.0, and 16.0% of all IEAs, respectively. Bowel (n = 10) and ureter (n = 3) injuries were rare. There was no intraoperative mortality. IAEs were associated with increased tumor size, tumor extent, age, comorbidity scores, surgical approach and indication, postoperative Clavien-Dindo (CD) complications and longer stay in hospital. 48% of conversions were reactive with more CD-complications after reactive than preemptive conversion (43 vs. 25%).

CONCLUSIONS

The associations between IAEs and preoperative variables and postoperative outcome indicate good construct validity for EAUiaiC. Bleeding is the most important IAE in kidney tumor surgery and the inclusion of transfusions could provide increased objectivity.

Disordered serum essential element levels are associated with increased risk of kidney tumors

Essential elements play vital roles in the regulation of carcinogenesis. We aimed to investigate the relationship between essential elements and kidney tumors. This study included 72 healthy individuals and 100 kidney tumor patients. The concentrations of cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), selenium (Se), and zinc (Zn) were determined by inductively coupled plasma mass spectrometry. The random forest model was used to evaluate the importance of each variable by using the randomForest package. The associations between essential elements and clinical tumor characteristics were examined by the Mann-Whitney U-test, and the log-rank test was used to assess the Kaplan-Meier curves. The levels of Co, Cr, Fe, Mn, Ni, and Zn in patients with kidney tumors were significantly lower. In the random forest model, the top two metallic features were Co and Zn. The Kaplan-Meier curve showed that patients with lower Co, Se, and Zn levels exhibited lower progression-free survival. In summary, this study gathered evidence that disordered essential elements are associated with kidney tumors and thus opens a new path to elucidate the etiology of kidney tumors from the perspective of environmental health and safety.

3D multi-scale residual fully convolutional neural network for segmentation of extremely large-sized kidney tumor

BACKGROUND AND OBJECTIVE

We propose a novel deep neural network, the 3D Multi-Scale Residual Fully Convolutional Neural Network (3D-MS-RFCNN) to improve segmentation in extremely large-sized kidney tumors.

METHOD

The multi-scale approach with a deep neural network is applied to capture global contextual features. Our method, 3D-MS-RFCNN, consists of two encoders and one decoder as a single complete network. One of the encoders is designed for capturing global contextual information by using the low-resolution, down-sampled data from input images. In the decoder, features from the encoder for global contextual features are concatenated with up-sampled features from the previous layer and features from the other encoder. Ensemble learning strategy is also applied.

RESULTS

We evaluated the performance of our proposed method using the KiTS public dataset and the in-house hospital dataset. When compared with the state-of-the-art method, Res3D U-Net, our model, 3D-MS-RFCNN, demonstrated greater accuracy (0.9390 dice score for KiTS dataset and 0.8575 dice score for external dataset) for segmenting extremely large-sized kidney tumors.

CONCLUSIONS

Our proposed network shows significantly improved segmentation performance of extremely large-sized targets. This study can be usefully employed in the field of medical image analysis.

Nephrometric score based on 3D modeling (3D nephrometry score) for the probability prediction of intra- and postoperative complications for kidney surgery

AIM

The purpose of the study is the development and evaluation of the informativeness of the author's 3D nephrometric score application to predict the probability of intraoperative and postoperative complications in kidney operations.

MATERIAL AND METHODS

The study includes 264 patients who underwent surgical treatment of renal tumors, before that CT and 3D modeling were carried out. All patients underwent an analysis of the surgical intervention complexity on the C-index, PADUA, R.E.N.A.L., and developed 3D nephrometric score. To determine the set of variables that allow to classify patients, the method of discriminant analysis was used to predict the nature, volume of blood loss, duration of ischemia, and the number of complications. The sensitivity and specificity of the predictors were estimated with the help of ROC analysis.

RESULTS

Indicators have been established to classify patients according to the probability of complications, the amount of blood loss and the duration of ischemia during surgery for kidney cancer. We have created linear models that predict the development of bleeding during surgery, the volume of blood loss of more than 200 ml and the duration of ischemia more than 20 min, as well as the likelihood of complications using discriminant functions. The proposed author's nephrometric score exceeds the capabilities of C-index, PADUA, R.E.N.A.L in many ways in blood loss and time of ischemia predicting, which allows us to recommend it for the assessment of resectability in kidney operations.

Superselective Ischemia in Robotic Partial Nephrectomy Does Not Provide Better Long-term Renal Function than Renal Artery Clamping in a Randomized Controlled Trial (EMERALD): Should We Take the Risk?

BACKGROUND

Superselective clamping of tumor-targeted arteries aims to eliminate ischemia of the remnant kidney while keeping tumor bed bloodless during excision.

OBJECTIVE

To evaluate the impact of superselective clamping on long-term renal function, compared with renal artery early unclamping.

DESIGN, SETTING, AND PARTICIPANTS

A randomized monocentric single-blind trial (1:1) was conducted from February 2018 to August 2019. Patients with a single renal tumor were candidates for a robot-assisted partial nephrectomy (RAPN) in a referral center. EMERALD (NCT03679572) was powered to include 50 patients with an interim analysis after 30 cases.

INTERVENTION

Superselective RAPN (SS-RAPN) with near-infrared fluorescence (NIRF) or conventional RAPN with renal artery early unclamping.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was the percent change of estimated glomerular filtration rate (eGFR) in the operated kidney after 6 mo (combination of eGFR and relative function on ^99mTc-DMSA scintigraphy). Secondary endpoints assessed feasibility and safety of the technique.

RESULTS AND LIMITATIONS

Relative eGFR reduction in the operated kidney at 6 mo did not differ significantly (-21.4% vs -23.4%, p=0.66). This absence of difference remained after adjusting on percentage of kidney volume preserved, which was an independent predictor of functional preservation. There were no significant differences in terms of blood loss, change in hemoglobin, postoperative complications, transfusion, and conversion to radical nephrectomy (two vs zero) or to open surgery (one vs zero). Despite a good accrual, the steering committee interrupted the trial after the interim analysis for futility given the absence of trend in favor of SS-RAPN.

CONCLUSIONS

SS-RAPN using NIRF does not provide better renal function preservation than renal artery clamping, questioning the interest of this technique at a higher risk of bleeding.

PATIENT SUMMARY

In this randomized controlled trial, superselective clamping of tumor feeding arteries did not show any advantage in terms of long-term renal function compared with conventional artery clamping.

The state of the art in kidney and kidney tumor segmentation in contrast-enhanced CT imaging: Results of the KiTS19 challenge

There is a large body of literature linking anatomic and geometric characteristics of kidney tumors to perioperative and oncologic outcomes. Semantic segmentation of these tumors and their host kidneys is a promising tool for quantitatively characterizing these lesions, but its adoption is limited due to the manual effort required to produce high-quality 3D segmentations of these structures. Recently, methods based on deep learning have shown excellent results in automatic 3D segmentation, but they require large datasets for training, and there remains little consensus on which methods perform best. The 2019 Kidney and Kidney Tumor Segmentation challenge (KiTS19) was a competition held in conjunction with the 2019 International Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI) which sought to address these issues and stimulate progress on this automatic segmentation problem. A training set of 210 cross sectional CT images with kidney tumors was publicly released with corresponding semantic segmentation masks. 106 teams from five continents used this data to develop automated systems to predict the true segmentation masks on a test set of 90 CT images for which the corresponding ground truth segmentations were kept private. These predictions were scored and ranked according to their average Sørensen-Dice coefficient between the kidney and tumor across all 90 cases. The winning team achieved a Dice of 0.974 for kidney and 0.851 for tumor, approaching the inter-annotator performance on kidney (0.983) but falling short on tumor (0.923). This challenge has now entered an "open leaderboard" phase where it serves as a challenging benchmark in 3D semantic segmentation.

[Malignant epithelioid angiomyolipoma of the kidney: a rare case]

Epitheloide angiomyolipoma (EAML) is a very rare type of benign mesenchymal angiomyolipoma. In contrast to classical angiomylipoma, lymph node metastases, local recurrence and distant metastases occur in one third of patients with EAML. We report the case of a 49-year-old patient with a large recurrence of EAML of the left kidney. According to the literature, this is the first case of a malignant EAML with local recurrence in Germany.

Leiomyosarcoma of the renal pelvis diagnosed by percutaneous endoscopic resection

We present a case of leiomyosarcoma arising from the renal pelvis, which is a rare clinical entity. A percutaneous endoscopic resection led to the final histopathological diagnosis. The patient underwent radical nephrectomy and did not receive adjuvant therapy. Based on follow-up CT scans, he remains recurrence-free one year after surgery.

Evaluating online filtering algorithms to enhance dynamic multispectral optoacoustic tomography

Multispectral optoacoustic tomography (MSOT) is an emerging imaging modality, which is able to capture data at high spatiotemporal resolution using rapid tuning of the excitation laser wavelength. However, owing to the necessity of imaging one wavelength at a time to the exclusion of others, forming a complete multispectral image requires multiple excitations over time, which may introduce aliasing due to underlying spectral dynamics or noise in the data. In order to mitigate this limitation, we have applied kinematic α and α β filters to multispectral time series, providing an estimate of the underlying multispectral image at every point in time throughout data acquisition. We demonstrate the efficacy of these methods in suppressing the inter-frame noise present in dynamic multispectral image time courses using a multispectral Shepp-Logan phantom and mice bearing distinct renal cell carcinoma tumors. The gains in signal to noise ratio provided by these filters enable higher-fidelity downstream analysis such as spectral unmixing and improved hypothesis testing in quantifying the onset of signal changes during an oxygen gas challenge.

Simultaneous totally robotic rectal resection and partial nephrectomy: case report and review of literature

Introduction

The incidence of synchronous RCC and colorectal cancer is heterogeneous ranging from 0.03 to 4.85%. Instead, only one case of huge colon carcinoma and renal angiomyolipoma was reported. The treatment of synchronous kidney and colorectal neoplasm is, preferably, synchronous resection. Currently, laparoscopic approach has shown to be feasible and safe, and it has become the gold standard of synchronous resection due to advantages of minimally invasive surgery. We presented a case synchronous renal neoplasm and colorectal cancer undergone simultaneous totally robotic renal enucleation and rectal resection with primary intracorporeal anastomosis. As our knowledge, this is the first case in literature of simultaneous robotic surgery for renal and colorectal tumor.

Case presentation

A 53-year-old woman was affected by recto-sigmoid junction cancer and a solid 5 cm left renal mass. We performed a simultaneous robotic low anterior rectal resection and renal enucleation. Total operative time was 260 min with robotic time of 220 min; estimated blood loss was 150 ml; time to flatus was 72 h, and oral diet was administered 4 days after surgery. The patient was discharged on the eighth post-operative day without peri- and post-operative complication. The definitive histological examination showed a neuroendocrine tumor pT2N1 G2, with negative circumferential and distal resection margins. Renal tumor was angiomyolipoma. At 23 months follow-up, the patient is recurrence free.

Discussion and conclusion

As our knowledge, we described the first case in literature of simultaneous robotic anterior rectal resection and partial nephrectomy for treatment of colorectal tumor and renal mass. Robotic rectal resection with intracorporeal anastomosis surgery seems to be feasible and safe even when it is associated with simultaneous partial nephrectomy. Many features of robotic technology could be useful in combined surgery. This strategy is recommended only when patients’ medical conditions allow for longer anesthesia exposure. The advantages are to avoid a delay treatment of second tumor, to reduce the time to start the post-operative adjuvant chemotherapy, to avoid a second anesthetic procedure, and to reduce the patient discomfort. However, further studies are needed to evaluate robotic approach as standard surgical strategy for simultaneous treatment of colorectal and renal neoplasm.

Assessing Genomic Copy Number Alterations as Best Practice for Renal Cell Neoplasia: An Evidence-Based Review from the Cancer Genomics Consortium Workgroup

Renal cell neoplasia are heterogeneous with diverse histology, genetic alterations, and clinical behavior that are diagnosed mostly on morphologic features. The Renal Cell Neoplasia Workgroup of the Cancer Genomics Consortium systematically evaluated peer-reviewed literature on genomic studies of renal cell carcinoma (RCC), including clear cell RCC, papillary RCC, chromophobe RCC, and the translocation RCC involving TFE3, TFEB and MITF rearrangements, as well as benign oncocytoma, which together comprise about 95% of all renal cell neoplasia. The Workgroup curated recurrent copy number alterations (CNAs), copy-neutral loss-of-heterozygosity (cnLOH), rearrangements, and mutations, found in each subtype and assigned clinical relevance according to established criteria. In clear cell RCC, loss of 3p has a disease-initiating role and most likely also in progression with mutations detected in VHL and other genes mapped to this arm, and loss of 9p and/or 14q has well-substantiated prognostic utility. Gain of chromosomes 7 and 17 are hallmark CNAs of papillary RCC, but patterns of other CNAs as detected by chromosomal microarray analysis (CMA) afford sub-classification into Type 1 and 2 with prognostic value, and for further sub-stratification of Type 2. Inherent chromosome loss in chromophobe RCC as detected by CMA is useful for distinguishing the eosinophilic variant from benign oncocytoma which in contrast exhibits few CNAs or rearranged CCND1, but share mitochondrial DNA mutations. In morphologically atypical RCCs, rearrangement of TFE3 and TFEB should be considered in the differential diagnosis, portending an aggressive RCC subtype. Overall, this evidence-based review provides a validated role for assessment of CNAs in renal cell neoplasia in the clinical setting to assist in renal cell neoplasm diagnosis and sub-classification within subtypes that is integral to the management of patients, from small incidentally found renal masses to larger surgically resected specimens, and simultaneously identify the presence of key alterations portending outcome in malignant RCC subtypes.

A Combination of the Mayo Adhesive Probability Score and the RENAL Score to Predict Intraoperative Complications in Small Renal Masses

INTRODUCTION

To evaluate the potential predictive value of the Mayo Adhesive Probability (MAP) score combined with the RENAL score for intraoperative outcomes in retroperitoneal laparoscopic nephron-sparing surgery (NSS) in an Eastern Asian population.

METHODS

An initial of 388 patients undergoing retroperitoneal laparoscopic NSS were identified. MAP and RENAL scores were calculated according to CT and a logistic regression model was adopted as a combination of the RENAL score and the MAP score.

RESULTS

A total of 293 patients were included. The overall intraoperative complication rate was 7.5% (21 cases). The MAP score was found to correlate with operation time (OT; r = 0.169), estimated blood loss (EBL; r = 0.318), and intraoperative complications (r = 0.242). The RENAL score was correlated with warm is-chemia time (r = 0.503), OT (r = 0.334), intraoperative complications (r = 0.178), and EBL (r = 0.218). The MAP score and the RENAL score were reliable predictors of overall intraoperative complications, with areas under the curve (AUC) of 0.728 and 0.759, respectively. After combination of these 2 scores, the AUC of overall intra-operative complications was improved with statistical significance (AUC = 0.847, combination vs. RENAL score: p = 0.044 < 0.05; combination vs. MAP score: p = 0.005 < 0.05).

CONCLUSION

The MAP score is an important predictor of EBL, OT, and intraoperative complications in retroperitoneal laparoscopic NSS and its combination with the RENAL score showed a superior predictive value compared to a single score in overall intraoperative complications. The MAP score might be considered in preoperative radiologic aspects as regularly as the RENAL score.

Selecting the Best Elements from Previous Kidney Tumor Scoring Systems to Restructure Efficient Predictive Models for Surgery Type

OBJECTIVE

The aim of this work was to select the best elements from previous scoring systems to restructure efficient predictive models for surgery type.

METHODS

Sixteen elements were selected from 7 systems (RENAL, PADUA, DAP, ZS, NephRO, ABC, and CI). They were divided into 6 categories (tumor max. size, exophytic/endophytic, correlation with collecting system or sinus, tumor location, contact situation with the parenchyma, invasion depth). Three elements, selected from 3 different categories, were integrated to establish a total of 320 new models. According to AUC rank, optimized models were developed, and these models were divided into 3 sections. An analysis of the distribution of the 6 categories was made to explore the predictive capacities of the models.

RESULTS

A total of 166 consecutive patients were included. Seventy-five patients underwent radical nephrectomy operations. The AUC of the 7 systems ranged from 0.81 to 0.844. Three optimized models (AUC 0.88) were developed to predict surgery type. These optimized models were composed of DAP (D), PADUA, (sinus), and ABC; DAP (D), RENAL (N), and ABC; NePhRO (O), PADUA (UCS), and ABC. Two categories ("exophytic/endophytic," p < 0.001; "correlation with collecting system or sinus," p = 0.001) were nonuniformly distributed.

CONCLUSIONS

Seven systems held good predictive power for surgery type. Three optimized models were developed. "Correlation with collecting system or sinus" is a critical factor for predicting surgery type.

Benign renal schwannoma: Case report and literature review

Renal schwannoma is a very infrequent tumor. It is usually benign and it does not have any specific symptoms or imaging characteristics. Its final diagnosis is usually made after surgery. We present a 66 year-old-man that was referred to our center after the casual finding of a renal mass. With a suspected diagnosis of a renal cell carcinoma, a partial nephrectomy was performed. The histological study revealed the final diagnosis of a benign renal schwannoma.

Diagnostic value of imprint cytology testing in kidney tumors: review of 200 cases

INTRODUCTION

Previous investigations have studied the importance of imprint cytology (IC) testing of core needle biopsy (CNB) from various organs. We have presented the largest series, to the best of our knowledge, of IC testing of CNB for patients with kidney tumors.

MATERIALS AND METHODS

The present retrospective study (January 1, 2015, through January 30, 2016) identified laboratory information through a computer search of the cytology archived reports for 200 consecutive IC testing with CNB for renal tumors cases. A board-certified cytopathologist and cytology-trained fellow reviewed the IC testing and CNB slides and rendered them as nondiagnostic, positive for malignancy, negative for malignancy, positive for neoplasm, or atypical. The tumors were graded using the International Society of Urological Pathology grading system. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated.

RESULTS

The IC testing cases classified as atypical (n = 53) or positive for neoplasm (n = 28) were evaluated separately because of the ambiguous morphologic characteristics. Of the other 119 cases, IC testing classified 95 (80%) as positive for malignancy, 5 (4%) as negative for malignancy, and 19 (16%) as nondiagnostic. The corresponding CNB histologic diagnoses showed that 85 of 95 cases (89%) were true positive for malignancy. Of these 85 cases, 45 (53%) were low grade, 21 (25%) were high grade, and 19 (22%) were ungraded. The corresponding sensitivity, specificity, and accuracy were 85%, 11%, and 58%, respectively. The 53 IC-identified atypical cases were more likely to be malignant (n = 40; 75%). Of the remaining IC testing atypical cases, 12 (23%) were negative for malignancy and 1 (2%) was nondiagnostic. Of the 28 cases positive for neoplasm using IC, 13 (46%) were positive and 15 (54%) were negative for malignancy.

CONCLUSIONS

The relatively low diagnostic value of IC testing for renal tumors showed it to be less powerful for screening than its use in other organs.

[Partial nephrectomy for renal masses >7cm: Morbidity, oncological and functional outcomes (UroCCR-7 study)]

OBJECTIVES

To describe the morbidity, mortality, oncological and functional results of Partial nephrectomy (PN) for the treatment of renal tumors of more than 7cm.

MATERIAL AND METHODS

Thirty-seven partial nephrectomies for tumors larger than 7cm operated in a single center between 1987 and 2016 were analyzed retrospectively. The pre, per and postoperative clinico-biological data were collected within the UroCCR database. The GFR was assessed at day 5, 1 month and last follow-up. Intraoperative and postoperative surgical complications, the recurrence rate and the overall and specific mortality were collected.

RESULTS

The mean age of the patients was 57 years (44-68). The preoperative GFR and the median tumor size were 80mL/min and 8cm, respectively. The indication for surgery was elective in 21 cases (60%) and 19 tumors (54%) were malignant. Postoperative complications occurred in 24,3 cases (24.3%). The median post-operative GFR was respectively 77mL/min, 80mL/min and 77mL/min at day 5, 1month and at last follow-up. With a median follow up of 31 months [1-168], 5 patients (26,3%) had metastatic progression of whom 1 (5.3%) had a concomitant local recurrence and 3 (15.8%) had died from cancer.

CONCLUSION

This study confirms the feasibility of PN for large tumors with acceptable morbidity, limited risk of local recurrence and excellent functional results.

LEVEL OF EVIDENCE

4.

Phyto-mediated synthesized multifunctional Zn/CuO NPs hybrid nanoparticles for enhanced activity for kidney cancer therapy: A complete physical and biological analysis

Cancer in human society is one of the most problematic health issue responsible for outnumbered deaths worldwide. The consumption of developed NPs in cancer diagnosis is a rapidly emerging field of bio-medical nanotechnology. Recent years, greener synthesized metal oxide hybrid nanoparticles have attracted great attention in cytotoxicity to different cancer therapy. Herein, we report that Duchesnea indica plant mediated green synthesis plant extract mediated Zn doped CuO (Zn/CuO) nanoparticles (NPs) prepared by hydrothermal method and these physico-chemical properties were characterized by XRD, UV-DRS, FTIR, and SEM with EDAX analytical techniques. The XRD pattern findings indicated that the crystal structure of the base CuO matrix are not distorted by the substitution of Cu²⁺ (0.73 Å) ions by Zn²⁺ (0.65 Å) ions. The average crystallite size of undoped and Zn/CuO NPs samples are found to be in between the range of 23 to 36 nm. And we can see that the Zn/CuO NPs are large aggregates, containing small particles with sizes of 100-300 nm with spherical shaped morphology by SEM and TEM microscopic images. The normal cell viability and cancer cell inhibition results on A-498 cancer cells and also normal human epithelial cells exhibited that no significant changes in the cell viability with normal kidney epithelial cells and doped NPs given excellent cell inhibition treated on A-498 kidney tumor cells.

FLCN: The causative gene for Birt-Hogg-Dubé syndrome

Germline mutations in the novel tumor suppressor gene FLCN are responsible for the autosomal dominant inherited disorder Birt-Hogg-Dubé (BHD) syndrome that predisposes to fibrofolliculomas, lung cysts and spontaneous pneumothorax, and an increased risk for developing kidney tumors. Although the encoded protein, folliculin (FLCN), has no sequence homology to known functional domains, x-ray crystallographic studies have shown that the C-terminus of FLCN has structural similarity to DENN (differentially expressed in normal cells and neoplasia) domain proteins that act as guanine nucleotide exchange factors (GEFs) for small Rab GTPases. FLCN forms a complex with folliculin interacting proteins 1 and 2 (FNIP1, FNIP2) and with 5' AMP-activated protein kinase (AMPK). This review summarizes FLCN functional studies which support a role for FLCN in diverse metabolic pathways and cellular processes that include modulation of the mTOR pathway, regulation of PGC1α and mitochondrial biogenesis, cell-cell adhesion and RhoA signaling, control of TFE3/TFEB transcriptional activity, amino acid-dependent activation of mTORC1 on lysosomes through Rag GTPases, and regulation of autophagy. Ongoing research efforts are focused on clarifying the primary FLCN-associated pathway(s) that drives the development of fibrofolliculomas, lung cysts and kidney tumors in BHD patients carrying germline FLCN mutations.

Renal Medullary Carcinoma with an Aggressive Clinical Course: A Case Report and Review of the Literature

Renal medullary carcinoma (RMC) is a rare, yet aggressive malignancy of the kidney that is found predominantly in young patients with African descent and sickle cell hemoglobinopathies and most specifically sickle cell trait. Due to its aggressive nature, most cases have metastasis or local invasion at the time of diagnosis. Prognosis is extremely poor with survival less than 1 year after diagnosis. Here we present a case of metastatic RMC in a 29-year-old African female. Despite chemotherapy with cisplatin, gemcitabine, and paclitaxel, and initial shrinkage of the tumor, the patient died 5 months after diagnosis.

Predictive Ability of Preoperative CT Scan in Determining Whether the Adrenal Gland is Spared at Radical Nephrectomy

INTRODUCTION

The aim of this study was to assess whether preoperative multiple detector computed tomography (MDCT) accurately predicts adrenal involvement for patients undergoing non-adrenal sparing radical nephrectomy for renal cell carcinoma.

METHODS AND MATERIALS

A retrospective observational study based on a composite patient population of two university teaching hospitals who underwent radical nephrectomy. Sensitivity, specificity, overall accuracy, positive and negative predictive values and likelihood ratios were calculated from radiological reports.

RESULTS

Total 579 patients underwent radical nephrectomy, of which 199 (34.4%) patients underwent a non-adrenal sparing radical nephrectomy, in which 128 (64.3%) were male and 118 (59.3%) were left side tumors. Mean tumor size was 8.2 cm (range 1.4-20cm). MDCT was found to have a sensitivity of 100% and specificity of 95.2% for identifying adrenal invasion. Total 179 patients (89.9%) had a radiographically normal ipsilateral adrenal gland, of which none were found to have adrenal involvement. Therefore, the negative predictive value of preoperative cross-sectional imaging for identification of adrenal involvement was 100%.

CONCLUSION

Cross- sectional MDCT imaging accurately predicts adrenal involvement and the decision to remove or spare the adrenal gland should be made preoperative planning regardless of tumour size or location at the time of multi-disciplinary discussion unless there is intraoperative evidence of adrenal invasion.

Secondary malignancies diagnosed using kidney needle core biopsies: a clinical and pathological study of 75 cases

Involvement of the kidney by secondary malignancies is uncommon. Differentiating secondary malignancies from primary kidney/urothelial tumors can be challenging, especially on limited biopsy material. A retrospective search of our institutional archive from January 2002 to May 2015 identified 1572 cases of imaging-guided needle core biopsies of the kidney. Of these, 75 (5%) cases revealed a secondary malignancy; 48 (64%) patients had undergone the biopsy with a primary kidney tumor favored clinically. There were 39 male and 36 female patients with a mean age of 59.4 years (range, 21-83 years). The majority of the cases (n = 55, 73%) were metastases from solid tumors, with lung being the most common primary site (n = 22, 29%). Diffuse large B-cell lymphoma was the most common hematological malignancy (n = 6) secondarily involving the kidney. Radiographically, 58 (77%) cases presented as a solitary kidney mass. The primary malignancy was known prior to the kidney biopsy in 66 (88%) cases. The mean interval between diagnoses of the primary tumor and secondary involvement of the kidney was 4.5 years. Immunohistochemical stains were performed in 65 (87%) cases. Follow-up information was available for 73 patients; mean survival was 19.4 months, with 43 patients dead of their disease (mean, 12 months) and 30 patients alive at last follow-up (21 with and 9 without disease; mean, 30 months). Secondary malignancy in the kidney may clinically and pathologically mimic primary kidney tumors. Accurate diagnosis can be rendered by correlating pathological features with clinical and radiographic findings and judicious use of ancillary studies.

Recurrent Non-islet Cell Tumor Hypoglycemia Secondary to Recurrent Renal Sarcoma

Introduction

Non-islet-cell tumor hypoglycemia (NICTH) is a rare paraneoplastic syndrome encountered in the setting of a wide variety of benign and malignant tumors.

Case presentation

A 46 year old lady was referred to our unit, with a large left sided retroperitoneal mass found on surveillance imaging on a background of renal sarcoma 6 years previously, for which she had a left nephrectomy. She had initially presented with symptoms of hypoglycaemia which was a result of tumor secretion of insulin like growth factor 2. She was counselled regarding the recurrence and listed for excision. On the day of surgery she developed symptomatic hypoglycaemia. The tumour was completely resected from the nephrectomy bed. The tumour was histologically identical to the initial tumor.

Conclusion

We report a rare case of recurrent non-islet cell hypoglycaemia in a lady with recurrent malignancy. Her hypoglycaemic episodes fully resolved on each occasion following resection. There have been reports of NICTH associated with recurrent retroperitoneal tumours and synchronous thyroid tumours and uterine leiomyomata. NICTH should be considered in patients with a known malignancy who present with recurrent hypoglycaemia. This is, to the best of our knowledge at the time of writing, the first case in the literature of recurrent NICTH secondary to recurrent renal sarcoma.

Thyroid-like follicular carcinoma of the kidney: one case report and review of the literature

OBJECTIVES

Thyroid-like follicular carcinoma of the kidney continues to confound the practicing pathologist with its close resemblance to the follicular variant of thyroid carcinoma, as well as other benign and malignant entities. Our goal is to expand the knowledge of this rare renal cell carcinoma subtype, which is morphologically similar to follicular carcinoma of the thyroid but lacks expression of characteristic thyroid immunohistochemical markers such as TTF-1 and thyroglobulin.

METHODS

We evaluated the gross, histologic, immunohistochemical, and fluorescence in situ hybridization (FISH) studies of a new case and performed a comprehensive review of the literature.

RESULTS

The lesion was spongy and well-circumscribed. Microscopically it showed variably sized follicular structures, filled with abundant, deeply eosinophilic, colloid-like material. At the periphery, it displayed areas resembling metanephric adenoma and early stages of nephrogenesis. The tumor cells strongly expressed CK7, PAX-8, PAX-2, vimentin, EMA, and CK19 immunostains. Other markers, such as CD10, RCC, HBME-1, thyroglobulin, and TTF-1, were not immunoreactive. The tumor was negative for trisomy of both 7 and 17 and showed borderline monosomies (losses) of both chromosomes in FISH studies.

CONCLUSIONS

Five years of preoperative observation and lack of recurrence bring further insight into the slow progressive nature of this neoplasm and support a low malignant potential. Proper identification is important to secure adequate treatment and follow-up.

Impact of preoperative radiological and postoperative pathological findings on survival of patients after radical nephrectomy performed with the indication of renal cell carcinoma

OBJECTIVE

To evaluate the impact of preoperative radiological and postoperative pathological findings on survival of patients after radical nephrectomy because of renal cell carcinoma (RCC).

MATERIAL AND METHODS

We performed 159 consecutive radical nephrectomy between December 2007 and January 2014. We evaluated age, gender, complaints, operation time, comorbidity, computed tomography (CT) and magnetic resonance graphy (MRG) results. Size of the mass, lymph node involvement, renal vein invasion, and presence of metastases were investigated. During histopathological examination, especially, pathological diagnosis, subtypes of RCC, lymph node involvement, lymphovascular, perineural invasion, and capsular, renal pelvis invasion, and renal vein involvement were sought. Follow-up periods of the patients were determined based on dates of death of the patients, and the study period.

RESULTS

RCC was seen in 124 (78%) of patients. Mean estimated suvival of RCC patients was 60 months and 5 year survival was 64%. Tumor size greater than 6.5 cm, lymph node involvement (p=0.006) and metastasis in radiological results (p<0.001), lymphovascular invasion (p=0.015) and stage of disease (p<0.001) found to be significantly affecting the survival. Lymph node involvement in radiological results (p=0.0089; HR: 4.6; CI 95%: 1.4753-14.3523) and stage of the disease (p= 0.0129; HR: 1.6; CI 95%: 1.1087-2.3461) were affecting the survival independently.

CONCLUSION

We found radiological lymph node involvement and stage of the disease as independent factors affecting the survival of RCC patients after radical nephrectomy.

Renal Angiomyxolipoma: Its First Appearance!

Angiomyxolipoma is considered a very rare subtype of lipoma, with the latter being the most common type of mesenchymal neoplasm. Only 17 cases have been described in English medical literature. Angiomyxolipomas have been described in many locations, mostly in the subcutaneous tissue. In this report, we present the first case of renal angiomyxolipoma ever encountered. Diagnosis was made after many differential diagnoses had been ruled out. Subsequent management and follow-up are illustrated along with a discussion and review of literature.

Malignant peripheral nerve sheath tumor of kidney-A case report

INTRODUCTION

Malignant peripheral nerve sheath tumors (MPNSTs) are very rare soft-tissue tumors. These tumors originate from Schwann cells or pluripotent perineural cells of the neural crest. An isolated MPNST of the kidney is extremely rare and has been reported in only six cases to date.

PRESENTATION OF CASE

A 30-year-old female with an unremarkable past medical and surgical history presented with an enlarging, right-sided abdominal mass for the last 3 months. A CT scan of the abdomen and pelvis showed a large exophytic mass arising from the right kidney. A metastatic work-up was negative, so a right radical nephrectomy was performed. Histopathological and immunohistochemical studies confirmed the diagnosis of an MPNST.

DISCUSSION

MPNSTs are rare and aggressive soft-tissue sarcomas that are usually associated with neurofibromatosis type 1 (NF-1) but that also occur post-radiation and sporadically. These tumors are highly malignant neoplasms with a high recurrence rate and distant metastases. Complete surgical excision remains the mainstay of treatment due to the limited response of MPNSTs to both chemotherapy and radiotherapy.

CONCLUSION

MPNSTs arising from the kidney are very rare. Complete surgical resection provides the only hope for cure. Postoperative chemotherapy and radiotherapy are still controversial, although postoperative radiotherapy is currently recommended by an oncology consensus group.

Robot-assisted partial nephrectomy: analysis of the first 100 cases from a single institution

Robot-assisted partial nephrectomy (RAPN) is an alternative to open and laparoscopic partial nephrectomy for small renal tumors. Our objectives were to report our experience and short-term outcomes from the first 100 cases of robot-assisted partial nephrectomy (RAPN) performed at a single institution, as well as to evaluate the effect of the learning curve and identify any factors associated with adverse perioperative outcomes. Patient records of the first 100 RAPN cases performed by three surgeons between October 2007 and March 2010 were retrospectively reviewed. The cases were divided into two groups to analyze a possible learning curve effect. Group 1 consisted of the first half (chronologically) of the cases performed by each surgeon, and Group 2 consisted of the second half. For the entire series, the median warm ischemia time was 24 min (range 11-49), mean length of follow-up was 13.4 months, and the median postoperative change in glomerular filtration rate (GFR) was -6.6 mL/min/1.73 m(2). Three patients had microscopically positive margins on final pathology, three intraoperative complications occurred, and 13 postoperative complications were recorded (10 Clavien grade IIIa or less). Median operative time was significantly longer in Group 1 (193 min) than in Group 2 (165 min, P = 0.003). Multivariate analysis identified male gender and cases done in Group 1 to be associated with increased operative time, while male gender and higher nephrometry scores were associated with increased blood loss. Tumor characteristics associated with greater reductions in GFR included higher nephrometry scores, endophytic tumors, and hilar tumors. In conclusion, RAPN appears to be safe and the major effect of the learning curve appears to be on operative time. Warm ischemia times are sufficiently low to prevent significant renal impairment, while male gender and higher nephrometry scores may be predictors of longer operative times and more intraoperative blood loss. Overall operative time decreased with increasing case volume, although this was not uniform among the three surgeons in the study. Further longitudinal study is necessary to establish oncologic outcomes.