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OBJECTIVE To quantify synchronous lung metastasis risk based on renal tumor size and determine a renal tumor size threshold to determine when chest imaging is warranted. METHODS We assessed 253,838 patients diagnosed with a renal tumor who underwent staging chest imaging between 2010 and 2016 within the National Cancer Database. Patients were stratified by renal tumor size in 10 mm increments, and synchronous lung metastasis risk was calculated for each category. Logistic regression analyses were used to test the relationship between renal tumor size and presence of synchronous lung metastasis after adjusting to all available covariables. RESULTS Overall, 14,524 out of 253,838 (5.7%) patients had evidence of synchronous lung metastasis. Median (IQR) tumor size for patients with vs without sLM was 90 mm (65-115) vs 40 mm (25-60), respectively. The incidence of synchronous lung metastasis was low for renal tumors

To compare the feasibility and outcomes of renal mass biopsies (RMB) of anatomically complex vs non-complex renal masses.Our institutional renal tumor database was queried for patients who underwent RMB between 2005 and 2019 and with available nephrometry score. Complex masses were: (1) small (2 cm), (2) entirely endophytic (nephrometry E=3), (3) hilar (h) or (4) partially endophytic (E=2) and anterior. Demographic and pathologic data were compared. Biopsies were deemed adequate if they resulted in a diagnosis. Concordance with surgical pathology was assessed. These were both presented using proportions. Factors associated with biopsy outcomes were identified using multivariable logistic regression. RMB sensitivity and specificity were calculated using contingency methods.A total of 306 RBMs were included, 179 complex and 127 non-complex. A total of 199 (65%) had an extirpative procedure. Complex lesions were less likely to have an adequate biopsy (89% vs 96%, P = .03), and to be concordant with final surgical pathology from an oncologic standpoint (89% vs 97%, P = .03). There was no significant difference in concordance of histology (76% vs 86%, P = .10) or grade (48 vs 51%, P = .66). On multivariable analyses, only male gender was associated with biopsy adequacy (OR 3.31, 95% CI 1.28-8.55, P = .01). Our overall sensitivity was 93%, specificity 93%, and accuracy 93%. There were no significant differences over time in biopsy outcomes during the study period.RMB of complex lesions is associated with excellent diagnostic yield, albeit lower than non-complex lesions. RMB should not be deferred in cases of anatomically complex lesions where additional data could improve clinical decision-making.

Acute Lobar Nephronia (ALN) is a rare infective condition of the kidney currently described only in case reports and small case series. The diagnosis of ALN is made by characteristic clinico-radiological findings. Differentiation from acute pyelonephritis, renal abscess and renal tumor is crucial for proper management and to avoid unnecessary diagnostic interventions. Herein, we report a 58-year-old woman with an uncontrolled diabetes mellitus, who was diagnosed clinically as acute pyelonephritis and treated with standard duration of antibiotics but had recurrence of symptoms. On evaluation, she was found to have ALN which was treated successfully with prolonged antibiotic course.

The incidence of renal tumor on the allograft kidney is relatively rare. There is no standard treatment available for the management of such cases. However, if technically feasible nephron-sparing surgical approaches, whether open or minimally invasive, should be preferred for the management of these challenging cases. To our knowledge, there is no pure laparoscopic technique reported in the literature but only 3 cases of robot-assisted partial nephrectomy. In this article, we aimed to present the application of pure transperitoneal laparoscopic partial nephrectomy for the management of a renal mass on the allograft kidney.

A case report of a 51-year-old man with left renal tumor and level II vena cava tumor thrombus (thrombus extending >2 cm above the renal vein, but below the hepatic veins) in a rare anatomical variant of renal vein. In nonmetastatic patients, aggressive surgical resection is widely accepted as the standard management option, but some doubts about the best practice in these patients are relevant. Surgical approach on those patients is a challenge for the surgeons, and anatomical variants make the procedure even more difficulty. These patients should be referring to a tertiary center because of the potential perioperative complexity.

Objective To provide a training tool to address the technical challenges of robot-assisted laparoscopic partial nephrectomy, we created silicone renal tumor models using 3-dimensional printed molds of a patient's kidney with a mass. In this study, we assessed the face, content, and construct validity of these models. Materials and Methods Surgeons of different training levels completed 4 simulations on silicone renal tumor models. Participants were surveyed on the usefulness and realism of the model as a training tool. Performance was measured using operation-specific metrics, self-reported operative demands (NASA Task Load Index [NASA TLX]), and blinded expert assessment (Global Evaluative Assessment of Robotic Surgeons [GEARS]). Results Twenty-four participants included attending urologists, endourology fellows, urology residents, and medical students. Post-training surveys of expert participants yielded mean results of 79.2 on the realism of the model's overall feel and 90.2 on the model's overall usefulness for training. Renal artery clamp times and GEARS scores were significantly better in surgeons further in training (P ≤.005 and P ≤.025). Renal artery clamp times, preserved renal parenchyma, positive margins, NASA TLX, and GEARS scores were all found to improve across trials (P Conclusion Face, content, and construct validity were demonstrated in the use of a silicone renal tumor model in a cohort of surgeons of different training levels. Expert participants deemed the model useful and realistic. Surgeons of higher training levels performed better than less experienced surgeons in various study metrics, and improvements within individuals were observed over sequential trials. Future studies should aim to assess model predictive validity, namely, the association between model performance improvements and improvements in live surgery.

Metanephric adenoma (MA) describes a rare renal tumor and is generally considered a benign lesion. However, there are cases with regional lymphogenic and distant metastases. Noninvasive diagnosis of MA using conventional imaging remains challenging. Here, we describe a case of histologically verified MA with additional advanced molecular imaging consisting of 18F-PSMA-1007 PET/CT, 99mTc-Sestamibi SPECT and contrast-enhanced ultrasound.

Cystic partially differentiated nephroblastoma (CPDN) is a rare multicystic renal tumor along the spectrum of cystic nephroma and cystic Wilms' tumor. There have only been two previously reported cases of bilateral CPDN in the literature. We present here a case of bilateral CPDN vs cystic Wilms' tumor treated with neoadjuvant and adjuvant chemotherapy in addition to a bilateral partial nephrectomy. We also review the relevant literature regarding CPDN in an effort to aid in diagnosis and management of these rare cystic renal tumors.

Wilms tumor is the most common renal tumor in children. However, tumor extension into the ureter is exceedingly rare. We present a case of bilateral Wilms tumor with unilateral ureteral extension into the bladder. This case illustrates the importance of thoughtful diagnostic evaluation and surgical planning to obtain a good oncologic outcome while preserving renal function.

To test whether a novel visuospatial testing platform improves trainee ability to convert two-dimensional to three-dimensional (3D) space.Medical students were recruited from Baylor College of Medicine and McGovern Medical School (Houston, TX). We 3D reconstructed 3 partial nephrectomy cases using a novel, rapid, and highly accurate edge-detection algorithm. Patient-specific reconstructions were imported into the dV-Trainer (Mimics Technologies, Seattle, WA) as well as used to generate custom 3D printed physical models. Tumor location was altered digitally to generate 9 physical models for each case, 1 with the correct tumor location and 8 with sham locations. Subjects were randomized 1:1 into the dV-Trainer (intervention) and No-dV-Trainer (control) groups. Each subject completed the following steps: (1) visualization of computed-tomographic images, (2) visualization of the reconstructed kidney and tumor in the dV-Trainer (intervention group only), and (3) selection of the correct tumor location on the 3D printed models (primary outcome). Normalized distances from the correct tumor location were quantified and compared between groups.A total of 100 subjects were randomized for this study. dV-Trainer use significantly improved subjects ability to localize tumor position (tumor localization score: 0.24 vs 0.38, P.001). However, subjects in the No-dV-Trainer group more accurately assigned R.E.N.A.L. scores.Even brief exposure to interactive patient-specific renal tumor models improves a novice's ability to localize tumor location. Virtual reality simulation prior to surgery could benefit trainees learning to localize renal masses for minimally invasive partial nephrectomy.

Hydatid disease or echinococcosis is a zoonotic disease caused by cestode Echinococcus granulosus. In humans, isolated renal involvement or primary renal hydatid cyst of the kidney is rare and accounts for about 1%-5% of all the cases of hydatid cyst. Isolated renal hydatid cyst can mimic cystic renal tumor both clinically and radiologically. We present a rare case of isolated hydatid cyst in a 38-year-old male who was diagnosed as a case of cystic renal tumor on radiology.

Nephrometry score systems, including RENAL nephrometry, preoperative aspects and dimensions used for an anatomical classification system, C-index, diameter-axial-polar nephrometry, contact surface area score, calculating resected and ischemized volume, renal tumor invasion index, surgical approach renal ranking score, zonal NePhRO score, and renal pelvic score, have been reviewed. Moreover, salient anatomic features like the perinephric fat and vascular variants also have been discussed. We then extract 7 anatomic characteristics, namely tumor size, spatial location, adjacency, exophytic/endophytic extension, vascular variants, pelvic anatomy, and perinephric fat as important features for partial nephrectomy. For novice surgeons, comprehensive and adequate anatomic consideration may help them in their early clinical practice.

Objective To construct high-fidelity, patient customized, physical, 3-dimensional (3D) models of renal units with enhancing renal lesions identified on cross-sectional imaging, which may aid patients, trainees, and clinicians in their comprehension, characterization, localization, and extirpation of suspicious renal masses. Methods Specialized software was used to import patient's diagnostic computerized tomography cross-sectional imaging into 3D printers and create physical 3D models of renal units with enhancing in situ lesions. Patients and trainees had the opportunity to manipulate the individualized model before surgical resection. Sterolithography additive manufacturing, a technique in which an ultraviolet laser is used to cure a photosensitive resin in sequential horizontally oriented layers, was used to build the models (Medical Modeling Inc., Golden, CO). Normal renal parenchyma was printed with a clear translucent resin, and red translucent resin delineated suspicious lesions. Renal vasculature and the proximal collecting system were printed in some models. Results We constructed 5 physical models of renal units with suspected malignancies before surgery. All patients successfully underwent partial nephrectomy (4 robotic and 1 open). Average ischemia time was 21 minutes, nephrometry score was 6.8, and all margins were negative. Anecdotally, patients, their families, and trainees consistently stated that the models enhanced their comprehension of the renal tumor in relation to surrounding normal renal parenchyma and hilar structures and improved understanding of the goals of the surgery. Conclusion Preoperative physical 3D models using available printing techniques can be constructed and may potentially influence both patients' and trainees' understanding of renal malignancies.

Objective To clearly define the proportions of benign vs malignant histologic findings in resected renal masses through an in-depth review of the contemporary medical data to assist in preoperative risk assessment. Materials and Methods PubMed and select oncology congresses were searched for publications that identify the histologic classification of resected renal masses in a representative sample from the contemporary data: [search] incidence AND (renal cell carcinoma AND benign); incidence AND (renal tumor AND benign); percentage AND (renal cell carcinoma AND benign); limit 2003-2011. Results We identified 26 representative studies meeting the inclusion criteria and incorporating 27,272 patients. The frequency of benign tumors ranged from 7% to 33%, with most studies within a few percentage points of the mean (14.5% ± 5.2%, median 13.9%). Clear cell renal cell carcinoma occurred in 46% to 83% of patients, with a mean of 68.3% (median 61.3; SD = 11.9%). An inverse relationship between tumor size and benign pathologic features was identified in 14 of 19 (74%) studies that examined an association between tumor size and pathologic characteristics. A statistically significant correlation between clear cell renal cell carcinoma and tumor size was identified in 13 of 19 studies (63%). The accuracy of preoperative cross-sectional imaging was low in the 2 studies examining computed tomography (17%). Conclusion Benign renal tumors represent ∼15% of detected surgically resected renal masses and are more prevalent among small clinical T1a lesions. Noninvasive preoperative differentiation between more and less aggressive renal masses would be an important clinical advance that could allow clinicians greater diagnostic confidence and guide patient management through improved risk stratification.

Wilms tumor is the most common malignant renal tumor in childhood, but it is rarely associated with a vascular tumor thrombus. We present a case of Wilms tumor with renal vein tumor thrombus treated with only a 3-port retroperitoneal laparoscopic technique in a 10-year-old girl. The patient was alive at the 12-month follow-up examination with adjuvant chemotherapy. To our knowledge, we present the first case of Wilms tumor with renal vein tumor thrombus treated with pure retroperitoneal laparoscopic management. Our technique can be recommended owing to the benefits of the superior recovery profile, a safer surgical route, and cosmetically more acceptable incisions.

Renal cell carcinoma is a rare renal tumor in the pediatric population with an incidence of 0.1-0.3%. We report on the first case of bilateral renal clear cell carcinoma that was treated by partial nephrectomies. We performed a complete genetic evaluation to exclude a family inheritance and we looked at the deletions associated with the possible histologic subtypes of renal cell carcinoma. The patient had no evidence of recurrence after 80-month follow-up and her renal function remained normal.

We describe a 3-month-old male infant who presented with gross hematuria and was found to have a renal mass and a testicular mass representing these two entities. This is the first case report of these two lesions presenting concomitantly.

The efficacy of radiofrequency ablation of large renal tumors can be increased by modulating their size and vascularity with antiangiogenic drugs, which may limit the sink effect related to high blood flow. We present an observation with 3 recurrent tumor locations, the largest being 3.7 cm in diameter. Pretreatment with antiangiogenics provided a significant reduction of tumor size and perfusion, allowing efficient ablation under favorable conditions.

Laparoscopic cryoablation is a minimally invasive treatment that is currently used to treat small renal tumors. Despite its growing use and promising outcomes, complications can occur. We report the first clinical case of urothelial sloughing with obstruction after cryoablation of a small renal tumor in a solitary kidney.

Primary primitive neuroectodermal tumors of the kidney are exceptionally rare and usually affect children and young adults. We report the first pediatric case of renal primitive neuroectodermal tumor presenting with tumor extension along the inferior vena cava to the right ventricle. This case highlights that when considering a renal tumor with significant intravascular extension in the pediatric age group, although the most likely diagnosis remains Wilms tumor, other rare entities may also demonstrate similar clinical and imaging features.

t p s idney malignancies are increasingly common and currently account for 3% of adult human ancers.1 Major risk factors include cigarette smokng, obesity, and hypertension.2,3 Currently, renal umors are classified by light microscopy using the orld Health Organization (WHO) system, which efines histopathologic subtypes with distinct clincal behavior and underlying genetic mutations. istopathologic classification is critical for clinical anagement, but is becoming more complex with ecognition of novel renal tumor subtypes, develpment of procedures yielding small diagnostic bipsies, and emergence of molecular therapies diected at tumor gene activity. Therefore, gene xpression-based classification systems are likely o become essential for diagnosis, prognosis, and reatment.

Perineal involvement in renal cell carcinoma (RCC) has not been reported. Vaginal metastases of RCC are also rare. We present a case of metastatic RCC, initially presenting as a perineal cyst. A 53-year-old woman presented with a perineal cyst, which was excised and diagnosed as clear cell carcinoma. A workup further revealed a vaginal mass and a renal tumor. A nephrectomy and local vaginal excision were performed, leading to the diagnosis of metastatic RCC. This case illustrates the variability in RCC presentation. Also, because vaginal clear cell carcinoma is rare, all such lesions should be considered potentially renal in origin.

Neuromuscular complications after percutaneous renal tumor ablation have not been previously reported. In a series of 48 patients undergoing percutaneous ablation, 3 of our patients had neuromuscular complications. One patient developed permanent flank laxity and two had transient paresthesias. Neuromuscular complications are uncommon, but may occur with percutaneous renal ablative surgery.

Objectives To evaluate, retrospectively, the staging accuracy of three-dimensional magnetic resonance imaging (3D-MRI) in our institution as a prelude to a prospective comparison of 3D-MRI and 3D computed tomography (CT) for preoperative planning of partial nephrectomy. In recent years, the use of 3D-CT for preoperative evaluation and surgical planning in patients undergoing nephron-sparing surgery has gained considerable popularity. Methods The images of 26 consecutive patients evaluated by 3D-MRI as part of the preoperative imaging studies for renal tumor were evaluated retrospectively and compared with the surgical pathologic findings to evaluate the ability of 3D-MRI to predict tumor multifocality, tumor stage, collecting system invasion, and venous invasion. Results 3D-MRI accurately predicted tumor multifocality in 1 of 2 cases. Imaging identified five of seven multifocal lesions. Two subcentimeter lesions were missed. Preoperative staging was correct in 29 of 30 lesions (97% accuracy). One T3b tumor was incorrectly staged as T2. Venous invasion was identified in 2 of 3 cases (67% sensitivity), but no false-positive results were seen. 3D-MRI had 100% sensitivity and 88% specificity in the prediction of collecting system invasion. Conclusions The staging accuracy of 3D-MRI appears to be quite good. Given the accuracy of this technique, along with the popularity of 3D imaging before renal surgery, these results provide the impetus for a future study directly comparing 3D-CT with 3D-MRI in the capacity of surgical preoperative planning.

A case of renal artery pseudoaneurysm (RAP) after partial nephrectomy for an 11-cm renal tumor is reviewed. Symptoms, computed tomography (CT) scan images and angiography are all displayed. A 57-year-old woman was readmitted 4 months after she underwent a retroperitoneal laparoscopic partial nephrectomy for an 11-cm right renal tumor. Contrast CT revealed a 10.3-cm mass recurrence in the same position as her former tumor. Renal arteriography confirmed active bleeding from the anterior upper pole segmental branch into a 3 × 3 × 7-cm pseudoaneurysm. Percutaneous selective coil angioembolization was successfully performed. The remaining kidney parenchyma was fully preserved.

Metanephric adenoma is an extremely rare renal tumor and, even more infrequently, is centrally located. Herein we summarize a series of images concerning a central metanephric adenoma in a female adult successfully treated with laparoscopic nephron-sparing surgery. The patient presented with no symptoms but was found to have a lesion in the middle portion of the left renal parenchyma for 1 month prior. She underwent retroperitoneal laparoscopic nephron-sparing surgery with total resection of the renal mass. To our knowledge, we present here the most detailed, challenging, and complicated laparoscopic nephron-sparing surgery yet to be reported with a diagnosis of metanephric adenoma in the central location.

Laparoscopic radical nephrectomy should be executed under the most fundamental principle of early ligature of the renal artery to prevent diffusion of cancerous cells. This is extremely true in the treatment of large renal tumors touching the main renal vasculature. Obviously, the concomitance of a duplicated inferior vena cava (IVC) with associated aberrant tributaries will significantly increase the surgical difficulty and the procedural risk of vascular injury. Herein we describe a transperitoneal left laparoscopic radical nephrectomy for a large hilar left renal tumor in the presence of a duplicated IVC with complicated anomalous tributaries by a transmesocolic approach.

We report a rare case and description of a benign pediatric renal mass. To our knowledge, this tumor has never been described in urologic published reports. It is possible that the identification of this renal tumor could spare a child the toxic adjuvant chemotherapy that would be administered if confused with histologically similar tumors such as clear cell sarcoma of the kidney.

Percutaneous radiofrequency ablation of renal tumors is known to be an effective treatment in patients with marginal renal function. Recently, this treatment was used in a patient with a renal tumor that arose in a single kidney. The tumor was completely ablated, but renal infarction developed because of a thermally injured segmental artery during ablation. We report the computed tomography imaging features, with an emphasis on the technical aspects of the ablation procedure.

We report the anatomic alterations in pelvic ectopic kidney and its bearing on the performance of laparoscopic radical nephrectomy (LRN) and its likely effect on the ultimate oncologic outcome. A patient with Stage T2N0M0 renal tumor in a pelvic kidney underwent transperitoneal LRN. LRN was performed by mobilizing the specimen with an adequate amount of perirenal fat, because no distinct Gerota’s fascia can be found in the pelvic kidney. At 1 year of follow-up, the patient was free of disease. LRN is a good option for managing localized renal tumor even in the pelvic kidney. The impact of the absence of Gerota’s fascia in the pelvic kidney needs further evaluation.

We describe the case of a 76-year-old man with a renal cell carcinoma thrombus extending into the right atrium, prolapsing across the tricuspid valve into the right ventricle during diastole, and producing sufficient portal venous pressure to result in intestinal venous thrombosis and necrosis of the upper gastrointestinal mucosa. The related published studies are reviewed and discussed.

Collecting duct carcinoma is a rare, highly aggressive, renal tumor arising from the distal collecting ducts. Various histologic patterns can be found in the same tumor but most demonstrate duct-like or papillary architecture surrounded by desmoplastic stroma. Grossly, these tumors are typically located in the medullary portion of the kidney near the region of the pelvis without extensive hemorrhage. It has a tendency to affect young patients and present at more advanced stages with a poorer prognosis. We describe a case of collecting duct carcinoma with histologic and immunohistochemical findings in a cortically located tumor.

A urinary enzyme pattern and kidney tissue pattern were investigated simultaneously in 117 urologic patients. In contrast to all other renal disorders only the sixteen malignant tumors of the kidney showed a significant drop of γ-GT in tumor tissue and urine. So far urinary enzymology has been used only as screening test. Measurement of γ-GT in urine, however, permits the diagnosis of kidney tumors.

Five cases of exophytic renal tumors are presented. In 2 cases selective renal angiography was nondiagnostic. In 3 cases, excretory urography demonstrated only minimal or misleading findings. In all cases cross-sectional imaging either by computed tomography or ultrasound helped establish the correct diagnosis. The potential sources of error in the evaluation of this uncommon type of renal tumor are stressed.

The second case of microscopic focal papillary carcinoma discovered in the wall ofsimple serous renal cyst, which showed negative results on cytologic examination, is presented. This lesion would have remained undiagnosed except for surgery. A modification of the accepted classification of coexistent renal tumor and cyst is proposed on the basis of histologic findings.

This is a case history of an unusual renal tumor in a horseshoe kidney that was noted serendipitously. No similar tumor is reported in the literature. Cystic lesions of the renal parenchyma are discussed.

With the advent of newer imaging modalities, angiography is no longer the choice either for the diagnosis or for the staging of renal cell carcinoma. For this reason, in the majority of patients routine preoperative angiography is probably not required. Angiography does, however, remain a valuable procedure and has specific indications in some patients with renal tumors including those patients in whom (1) the lesion is wholly intrarenal and does not disturb renal contcur, (2) there is a suspicion of a vascular abnormality, (3) there are indeterminate CT findings, (4) the inferior vena cava or renal vein is not adequately visualized on CT, (5) the renal tumor is bulky or excessively large, or (6) preoperative embolization is considered.

A rare case of primary renal neoplasm metastatic to the penis in a fifty-seven-year-old man is presented. The unusual features of a renal tumor on the right side with initial presentation as malignant priapism, and invasion of the urethral lumen without hematuria or other urinary symptoms are discussed. Pertinent literature is reviewed.

An animal model simulating the necessity of replacing the inferior vena cava (IVC) with a prosthetic graft is described. Six dogs underwent replacement of the IVC with an expanded polytetrafluoroethylene (E-PTFE) graft using an interrupted-suture technique. Three dogs served as controls, undergoing resection and autograft of the native IVC. Distal side-to-side femoral arteriovenous fistulas were constructed in each case and allowed to remain for six weeks. Subcutaneous heparin and prophylactic antibiotics were administered in the early postoperative period. All grafts were patent at six months, indicating a potentially successful technique for reconstruction of the IVC involved in disease or trauma.

A case of renal cell carcinoma and angiomyolipoma occurring in the same kidney in a patient without stigmata of tuberous sclerosis is reported. This case was managed as malignant renal tumor, and the patient underwent radical nephrectomy. Urologic and angiographic literature regarding angiomyolipoma is reviewed, and we find the neovascularity of this benign tumor is only rarely distinguishable from malignant renal tumor.

We successfully have used nephrotomography as a further diagnostic test to rule out the possibility that an avascular renal mass, demonstrated initially by selective renal angiography, represents an avascular solid renal tumor. The important diagnostic sign is the visualization of a definite thickening of the tumor wall on good-quality nephrotomographic studies. Most of these solid avascular tumors have proved to be papillary adenocarcinoma. Other diagnostic tests, such as cyst puncture, are excellent studies but simplicity, safety, and accuracy (with adequate examinations) are important considerations. A renal cyst may be diagnosed with confidence by using good-quality nephrotomographic studies without the necessity for renal angiography.

A renal tumor developing in a patient receiving cyclophosphamide (Cytoxan) therapy for Wegener granulomatosis is reported. The tumor was similar histologically to the “im-m-munoblastie” sarcoma that develops in renal allograft recipients as a complication of immunosuppressive therapy. This case report strengthens the cause and effect relationship between immunosuppressive drug usage and the subsequent development of neoplasia.