Incidental Detection of TFEB-Amplified Renal Cell Carcinoma by Colocated Gene Amplification of CCND3 (6p21): A Case Report and Review of the Literature

TFEB-amplified renal cell carcinoma (RCC), which belongs to the MITF family of RCC, is characterized by genomic amplification at the 6p21.1 locus where the TFEB gene is located. The vascular endothelial growth factor A and cyclin D3 genes are also located at this same locus. When tumors lack classic morphologic features, they may be classified as "RCC not otherwise specified (NOS)." However, it is increasingly important to accurately diagnose the RCC subtype to define the patient's individual prognosis and select the subsequent therapeutic modalities, which now include targeted agents. Therefore, knowledge of the diagnostic features of TFEB-altered RCCs, such as t(6;11) RCCs and TFEB-amplified RCCs, is critical for identifying these tumors. Herein, we present an interesting case of TFEB-amplified RCC that was initially diagnosed as RCC NOS on biopsy of a renal tumor in a community practice setting with available molecular findings demonstrating CCND3 amplification. The genetic abnormality was "accidentally" detected due to the amplification of the colocated CCND3 gene at the 6p21 locus of the TFEB gene on a limited genetic sequencing panel. This case highlights the importance of molecular tests in accurately diagnosing RCC and carefully interpreting molecular findings in the context of histomorphologic features.

Intra-Abdominal Epithelioid Neoplasm With EWSR1::CREB Fusions Involving the Kidney: A Clinicopathologic and Molecular Characterization With an Emphasis on Differential Diagnosis

Soft tissue neoplasms, harboring fusions between EWSR1 and FUS with genes encoding CREB transcription factors family (ATF1, CREB1, and CREM), are an emerging heterogeneous group of mesenchymal tumors that differ significantly in morphology, immunophenotypes, and behavior. Recently, EWSR1/FUS::CREB fusions have been recognized to define a group of aggressive neoplasms of epithelioid morphology with multiple growth patterns and a striking predilection for mesothelial-lined cavities. These neoplasms presenting as a primary neoplasm of intra-abdominal visceral organs are rare, which could elicit a wide range of differential diagnoses because of their diverse morphologies and immunohistochemical profiles. We report 3 cases of intra-abdominal epithelioid neoplasms with EWSR1::CREB fusions involving the kidney. This study included 2 female patients and 1 male patient, with age at presentation ranging from 17 to 61 years (mean: 32 years). All the patients underwent radical nephrectomy without adjunctive therapies. Grossly, the tumors were large, and all were solitary masses with sizes ranging from 5.6 to 30.0 cm (mean: 14.5 cm). Histologically, the neoplasms showed infiltrating and indistinct borders and were composed predominantly of monomorphic round-to-epithelioid cells with variable amounts of pale-to-clear cytoplasm, arranged in cords, nests, and sheets and embedded in a sclerotic hyalinized stroma with variable lymphoid cuffing either intermixed or at the periphery. Notably, a hemangiopericytomatous growth pattern was commonly seen. Nuclear atypia was mild, and mitotic activity was scarce. Immunohistochemically, all 3 cases were at least focally positive for epithelial membrane antigen and keratin AE1/AE3, with 2 tumors showing focal MUC4 expression and 1 case displaying diffuse CD34 and focal CAIX positivity. Targeted RNA sequencing identified EWSR1::CREM fusion in 2 cases and EWSR1::ATF1 fusion in 1 case. Subsequent fluorescence in situ hybridization analysis confirmed the RNA sequencing results. On follow-up, 1 patient developed multiple spinal bone metastases 5 months after the surgery while the other 2 patients were free of disease 9 and 120 months after diagnosis, respectively. Our findings demonstrate that intra-abdominal epithelioid neoplasms with EWSR1::CREB fusions may rarely occur primarily in the kidney and should be included in the differential diagnosis of primary renal epithelioid mesenchymal neoplasms.

Unmasking the Mystery of Renal Neoplasm in a Perimenopausal Woman: A Case Report

Mixed epithelial and stromal tumor (MEST) is a benign, complex, and rarely encountered renal neoplasm. This case involves a 46-year-old perimenopausal woman who presented with symptoms, such as abdominal pain, burning sensation during urination, increased urinary frequency, and hesitancy. Computed tomography (CT) urography revealed an exophytic, heterogeneously hyperdense mass originating from the interpolar and lower pole parenchyma of the left kidney, suggesting a neoplastic origin. Due to concerns about malignancy and the presence of local symptoms, a laparoscopic-assisted left radical nephrectomy was performed. Histopathological examination of the excised tissue revealed a biphasic neoplasm consisting of epithelial and stromal elements. The epithelial component exhibited cysts and glands of variable sizes, lined by columnar cells and surrounded by stromal tissue. The diagnosis of MESTs of the kidney was established and confirmed through immunohistochemistry. This unique type of benign kidney tumor can be effectively managed through conservative surgery and is associated with a favorable prognosis.

A Rare Case of Solitary Fibrous Tumor of the Kidney

Solitary fibrous tumor (SFT), originally described in the pleura, is a rare mesenchymal neoplasm characterized by a wide spectrum of clinical presentations and histopathological features. Over the years, SFTs have been reported in various anatomical locations, including soft tissues, visceral organs, and, uncommonly, the kidney. While SFTs primarily arise from the pleura, their occurrence in the kidney is an infrequent phenomenon, accounting for a minute fraction of all renal tumors. This case report presents a unique instance of a solitary fibrous tumor originating in the kidney, highlighting its clinical, radiological, and histopathological characteristics, as well as the challenges associated with accurate diagnosis and appropriate management. The rarity of such cases underscores the importance of comprehensive evaluation and awareness among clinicians and pathologists to ensure timely diagnosis and effective treatment strategies. Here, we report a case of SF of the kidney (SFT-K) located in the renal pelvis in a 39-year-old Caucasian female.

Eosinophilic Variant of Chromophobe Renal Cell Carcinoma During Pregnancy: A Multidisciplinary Approach and Successful Management in a Tertiary Hospital in Mexico

Renal cell carcinoma (RCC) is rarely diagnosed during pregnancy and its management represents a challenge as it necessitates considerations for the well-being of both the mother and the developing fetus. Diagnosis can be challenging and is often an incidental finding during routine imaging, which can lead to difficult decision-making. The choice of the ideal imaging study in these cases is a matter of debate. When the tumor is detected at an early stage, radical nephrectomy is indicated. However, there is still controversy regarding whether it should be performed conventionally or laparoscopically, as both techniques have their risks and benefits. In this context, our primary objective was to provide adequate surgical treatment for the patient, while safeguarding fetal health. Here, we present a patient with a history of recurrent miscarriages, in whom a renal tumor was incidentally diagnosed during pregnancy. Adding to the uniqueness of this case, the patient was diagnosed with an eosinophilic variant of chromophobe RCC through histopathological analysis. Our aim is to highlight the controversies surrounding diagnostic and treatment methodologies and to present the surgical techniques employed in this unique situation. This case underscores the importance and need for a multidisciplinary approach, which, in our instance, resulted in favorable outcomes for both maternal and neonatal health.

Mixed Epithelial Stromal Tumor of the Kidney With a Mesenteric Lymph Node: A Case Report and Literature Review

Mixed epithelial and stromal tumor (MEST) of the kidney belongs to the broad spectrum of renal neoplasms, distinguished by their varying composition of stromal to epithelial components. The histopathological display of the biphasic growth pattern of mesenchymal and epithelial elements, often with estrogen and progesterone receptor positivity, clinches the diagnosis. It is typically benign, with low recurrence rates and excellent prognosis after surgical resection. MEST constitutes a rare and unique subset, with limited research and understanding, requiring differentiation from other renal tumors. Our patient's presentation of a morphologically benign renal MEST with an imaging-positive inferior mesenteric lymph node renders this case exceptionally rare.

A Giant Oncocytoma in an Elderly Female Patient: A Case Report

Renal oncocytomas are rare, benign tumors that can be difficult to distinguish from malignant renal cell carcinomas. This case report presents an 84-year-old woman with a sizeable renal oncocytoma and discusses this rare entity's diagnostic challenges and management.

MED15::TFE3 Renal Cell Carcinomas: Report of Two New Cases and Review of the Literature Confirming Nearly Universal Multilocular Cystic Morphology

We report two novel cases of Xp11 translocation renal cell carcinomas with the MED15::TFE3 gene fusion in adult females aged 40 and 74 years. Both cases were extensively cystic and contained only minimal clear cells lining cysts and within septal walls, raising the differential diagnosis of multilocular cystic renal neoplasm of low malignant potential. By immunohistochemistry, both neoplasms labeled for PAX8, TFE3, cathepsin K and Melan A but not for HMB45. On review of the published literature and the two cases reported herein, over 90% of MED15::TFE3 renal cell carcinomas (RCCs) have been described as cystic. The correlation of the MED15::TFE3 fusion with extensively cystic morphology represents the strongest association of TFE3 fusion partner with clinicopathological features among TFE3-rearranged RCC reported to date.

Etiologies, Gross Appearance, Histopathological Patterns, Prognosis, and Best Treatments for Subtypes of Renal Carcinoma: An Educational Review

Of all primary renal neoplasms, 80-85% are renal cell carcinomas (RCCs), which develop in the renal cortex. There are more than 10 histological and molecular subtypes of the disease, the most frequent of which is clear cell RCC, which also causes most cancer-related deaths. Other renal neoplasms, including urothelial carcinoma, Wilms' tumor, and renal sarcoma, each affect a particular age group and have specific gross and histological features. Due to the genetic susceptibility of each of these malignancies, early mutation discovery is necessary for the early detection of a tumor. Furthermore, it is crucial to avoid environmental factors leading to each type. This study provides relatively detailed and essential information regarding each subtype of renal carcinoma.

On-Clamp vs. Off-Clamp Robot-Assisted Partial Nephrectomy for cT2 Renal Tumors: Retrospective Propensity-Score-Matched Multicenter Outcome Analysis

We compared perioperative outcomes after on-clamp versus off-clamp robot-assisted partial nephrectomy (RAPN) for >7 cm renal masses. A multicenter dataset was queried for patients who had undergone RAPN for a cT2cN0cM0 kidney tumor from July 2007 to February 2022. The Trifecta achievement (negative surgical margins, no severe complications, and ≤ 30% postoperative estimated glomerular filtration rate (eGFR) reduction) was considered a surrogate of surgical quality. Overall, 316 cases were included in the analysis, and 58% achieved the Trifecta. A propensity-score-matched analysis generated two cohorts of 89 patients homogeneous for age, ASA score, preoperative eGFR, and RENAL score (all p > 0.21). Compared to the on-clamp approach, OT was significantly shorter in the off-clamp group (80 vs. 190 min; p < 0.001), the incidence of sRFD was lower (22% vs. 40%; p = 0.01), and the Trifecta rate higher (66% vs. 46%; p = 0.01). In a crude analysis, >20 min of hilar clamping was associated with a significantly higher risk of sRFD (OR: 2.30; 95%CI: 1.13−4.64; p = 0.02) and with reduced probabilities of achieving the Trifecta (OR: 0.46; 95%CI: 0.27−0.79; p = 0.004). Purely off-clamp RAPN seems to be a safe and viable option to treat cT2 renal masses and may outperform the on-clamp approach regarding perioperative surgical outcomes.

Adult Wilms Tumor: Genetic Evidence of Origin of a Subset of Cases From Metanephric Adenoma

The genetics of nephroblastoma (Wilms tumor) occurring in adults is largely unknown, as studies have largely been limited to isolated case reports. We, therefore, studied 14 adult Wilms tumors for genetic alterations, using expanded targeted sequencing on 11 cases. The patients ranged from 17 to 46 years of age (mean and median, 31 y), and there were 8 males and 6 females. Five Wilms tumors harbored BRAF V600E mutations. All of these had better-differentiated areas identical to metanephric adenoma, as has previously been described. In 3 such cases, microdissection studies revealed that the BRAF V600E mutation was present in both the metanephric adenoma and Wilms tumor areas; however, additional genetic alterations (including TERT promoter mutations in 2 cases, ASLX1/ATR mutations in 1 other case) were limited to the Wilms tumor component. These findings suggest that the Wilms tumor developed from the metanephric adenoma. Other adult Wilms tumors harbored genetic alterations previously reported in the more common pediatric Wilms tumors, including WT1 mutations (2 cases), ASLX1 mutations (3 additional cases), NSD2 mutation (1 additional case), and 11p loss (3 cases). In summary, a significant subset of adult Wilms tumors (specifically those of epithelial type with differentiated areas) harbor targetable BRAF V600E mutations and appear to arise from metanephric adenomas as a consequence of additional acquired genetic alterations. Other adult Wilms tumors often harbor genetic alterations found in their more common pediatric counterparts, suggesting at least some similarities in their pathogenesis.

Atrophic Kidney Like Lesion: A Provisional Entity With Brief Review of Literature

Atrophic kidney-like lesion (AKLL) is a provisional renal entity with distinct morphological and immunohistochemical features. It characteristically resembles thyroid-like follicular renal cell carcinoma (RCC) of kidney, an emerging renal entity. Very few patients of AKLL have been reported in the literature. We are hereby describing the clinicopathological features of AKLL in a 38-year-old man. The patient was incidentally found to have a renal mass and underwent radical nephrectomy. The morphological and immunohistochemical findings revealed features of AKLL. The patient on 24 months' post-operative period follow-up is alive without recurrence or metastasis.

Application of the indocyanine green fluorescence imaging method in laparoscopic resection of a solitary retroperitoneal metastasis of renal cell carcinoma: A case report

Fluorescence image-guided surgery has improved intraoperative identification of anatomic structures including visualization of vascular anatomy. Herein, indocyanine green (ICG) fluorescence imaging was applied to identify of a recurrent small tumor of renal cell carcinoma (RCC) during laparoscopic surgery. The patient underwent left laparoscopic radical nephrectomy via the retroperitoneal approach for RCC (clear cell carcinoma, pT1bN0M0) at the age of 39 years. A solitary retroperitoneal mass (14 mm in diameter) was identified in a computed tomography scan 6 years after surgery. We performed laparoscopic resection with the application of the ICG angiography, because RCC is recognized as one of the most hypervascular cancers. The tumor was clearly visualized by fluorescence. Histopathological diagnosis of the resected tumor was recurrent RCC (low grade, G1). The patient remained free of disease at 2 years after surgery. The ICG fluorescence imaging would be a useful method for identification of metastatic small lesions of RCC during laparoscopic surgery.

Clinicopathological Profile of Renal Cancer in a Caribbean Hospital: Analysis of a Surgical Case Series

Objective

To document the demographic and pathological profile of renal cancer at San Fernando General Hospital (SFGH), Trinidad and Tobago over a five-year period (2015-2019).

Methods

This is a retrospective study that was conducted on all patients who had a histological diagnosis of renal cancer with surgical treatment from 2015-2019 at SFGH. Data were collected on patient demographics, clinical presentation, and pathological characteristics such as cancer size, location, and grade. Data were tabulated on Microsoft Excel and results were summarized using descriptive statistics.

Results

Over a 5-year period, there were 42 patients diagnosed with kidney cancer who had surgical intervention. The age ranged from 18 to 81 years with a mean age of 61 years and 67% of patients were over the age of 60. Males consisted of 57% of all patients. Most patients presented with pain, hematuria, or both. The majority (93%) of the patients had radical surgical treatment with equal distribution of right and left tumors. Clear cell carcinoma is the most common renal cell carcinoma (RCC), accounting for 80.5% followed by papillary with 16.7%. The majority of renal cell tumors were Fuhrman grade 2 with negative surgical margins and no lymphovascular invasion. The average maximum tumor dimension was 4.2 cm.

Conclusions

This study shows that in our hospital renal cancer affects primarily older patients, mostly men with the common presentation of pain and hematuria. The tumors are commonly clear cell RCC, grade 2 with negative margins, no lymphovascular invasion, and an average maximum dimension of 4.2 cm.

Recurrence Risk of Renal Cell Carcinoma Lingers Even Decades After Nephrectomy

Renal cell carcinoma (RCC) is a common malignancy in elderly males. Metastatic spread of this cancer is not an uncommon occurrence, even after nephrectomy. Lung, bone, liver, and brain are the most frequently involved sites. Such a type of presentation mostly occurs within five years after nephrectomy however, cases have been reported later as well. Here, we report a case of metastatic renal cell carcinoma that presented in the form of a lung growth 28 years after nephrectomy. This highlights the importance to consider relapsed metastatic renal cancer in the differential, even decades after its surgical removal.

Growth and renal function dynamics of renal oncocytomas in patients on active surveillance

OBJECTIVES

To study the natural history of renal oncocytomas and address indications for intervention by determining how growth is associated with renal function over time, the reasons for surgery and ablation, and disease-specific survival.

PATIENTS AND METHODS

The study was conducted in a retrospective cohort of consecutive patients with renal oncocytoma on active surveillance reviewed at the Specialist Centre for Kidney Cancer at the Royal Free London NHS Foundation Trust (2012 to 2019). Comparison between groups was performed using Mann-Whitney U-tests and chi-squared tests. A mixed-effects model with a random intercept for patient was used to study the longitudinal association between tumour size and estimated glomerular filtration rate (eGFR).

RESULTS

Longitudinal data from 98 patients with 101 lesions were analysed. Most patients were men (68.3%) and the median (interquartile range [IQR]) age was 69 (13) years. The median (IQR) follow-up was 29 (26) months. Most lesions were small renal masses, and 24% measured over 4 cm. Over half (64.4%) grew at a median (IQR) rate of 2 (4) mm per year. No association was observed between tumour size and eGFR over time (P = 0.871). Nine lesions (8.9%) were subsequently treated. Two deaths were reported, neither were related to the diagnosis of renal oncocytoma.

CONCLUSION

Natural history data from the largest active surveillance cohort of renal oncocytomas to date show that renal function does not seem to be negatively impacted by growing oncocytomas, and confirms clinical outcomes are excellent after a median follow-up of over 2 years. Active surveillance should be considered the 'gold standard' management of renal oncocytomas up to 7cm.

Renal Medullary Carcinoma in an Adolescent With Unknown Sickle Cell Trait

Renal medullary carcinoma (RMC) is an aggressive and rare malignancy that usually presents in adolescents and young adults with sickle cell disease. Herein, we describe a case of a white male with an unknown sickle cell trait, who presented with left iliac fossa pain, without any other finding that suggested renal neoplasia.

Imaging findings were a renal mass of central location with caliectasis, renal hilar adenopathy, and paraaortic lymphadenopathy. Biopsy confirmed an RMC diagnosis.

RMC diagnosis requires clinical suspicion in sickle cell patients who present with pain and hematuria. Imaging shows a central mass, with an infiltrative appearance, frequently associated with calyx’s dilation and lymphadenopathy. Prognosis is poor in spite of the treatment.

CT and MRI characteristic findings of sporadic renal hemangioblastoma: Two case reports

RATIONALE

Hemangioblastomas in the kidney are rare. Although a few cases of renal hemangioblastoma (RH) have been reported, the content of these articles mainly focused on clinical and pathological research, with minimal descriptions of radiologic findings. Moreover, there are no descriptions of magnetic resonance imaging (MRI) with enhancement of this condition. Herein, we report 2 cases of RH with computed tomography (CT) and MRI findings.

PATIENT CONCERNS

Two patients presented to our institution because of dull pain in the left abdomen, and a mass in the left kidney was found by ultrasound examination in each case. The patient had no special family history. Physical examination revealed no obvious tenderness or percussion pain in the renal and ureteral walking areas, and there was no obvious mass. Routine blood and urine tests were normal, and the serum tumor markers were negative. No obvious lesions were found on imaging of the other body parts.

DIAGNOSIS

Similar radiologic findings were observed in both cases and mimicked those of cavernous hemangiomas of the liver, including peripheral nodular enhancement in the corticomedullary phase, progressive centripetal enhancement in the nephrographic and delayed phases, and occasional complete "filling in" in the delayed phase. We made a radiologic diagnosis of renal clear cell carcinoma for patient 1 and suspected renal clear cell carcinoma for patient 2, but the pathological results showed RH.

INTERVENTIONS

Given the suspicion of renal cell carcinoma, both patients underwent partial nephrectomy.

OUTCOME

The recovery of the two patients was uneventful, and there was no evidence of local recurrence or metastasis many years after surgery.

LESSONS

RH is a rare benign tumor that can be easily misdiagnosed as clear cell carcinoma. Characteristic CT and MRI manifestations may improve preoperative diagnostic accuracy to avoid surgery or indicate nephron-sparing surgery.

Anaplastic nephroblastoma with peritoneal metastasis in an adult female Sprague Dawley rat

Spontaneous nephroblastomas are uncommon tumors of laboratory rats. This report describes a spontaneous nephroblastoma with peritoneal metastasis in an 11-month-old, female Sprague Dawley rat. The rat was part of a breeding program and presented 15 days post parturition with clinical signs including tachypnea, dyspnea and abdominal distension. At necropsy, the right kidney was markedly enlarged by an expansile pale-tan to white multinodular mass with extension into the retroperitoneal space, with multifocal variably sized nodules involving the mesentery, and surface of pancreas, liver, uterus, and ovarian bursa. The rat also had severe bicavitary effusion. Histologically, the renal parenchyma of the affected kidney was replaced by a moderately cellular, poorly-demarcated, non-encapsulated, multilobulated mass that appeared to compress the adjacent renal outer medulla and cortex. Three distinct neoplastic cell populations were identified in this renal tumor: epithelial cells (convoluted and dilated tubules / rare primitive glomeruloid structures), mesenchymal (neoplastic spindle cells in connective tissue), and blastemal cells (primitive neoplastic cells). The extrarenal nodular masses were predominantly composed of neoplastic mesenchymal and pleomorphic blastemal cells. Immunohistochemically, neoplastic epithelial cells in the renal mass were positive for pancytokeratin, and blastemal cells in both renal and extrarenal masses were positive for Wilms’ tumor 1 protein (WT1) and vimentin. Neoplastic mesenchymal elements in both renal and extrarenal masses were positive for vimentin. The neoplasm was negative for chromogranin A and S100. The tumor was classified as an anaplastic nephroblastoma with metastasis to the mesentery and peritoneal organs.

Three-dimensional reconstruction facilitates off-clamp laparoscopic partial nephrectomy for stage cT1b renal tumors

Background

This study aimed to evaluate the role of three-dimensional (3D) reconstruction of T1b renal tumors in the off-clamp laparoscopic partial nephrectomy (LPN).

Methods

A total of 40 consecutive patients undergoing LPN for stage cT1b renal tumor between January 2018 and July 2018 were included. Twenty received off-clamp LPN under the guidance of 3D reconstruction (3D group), and remaining 20 underwent off-clamp LPN under the guidance of conventional computer tomography arteriography (CTA group). The demographics, perioperative characteristics and renal function were compared between groups.

Results

All the procedures were performed successfully without conversion to main renal artery clamping. There were no significant differences in the age, gender, body mass index (BMI), tumor size, and RENAL score between two groups. The mean operation time (OT) was significantly shorter and estimated blood loss markedly less in the 3D group than in the CTA group. Incidence of postoperative complications was 5% in the 3D group and 10% in the CTA group (P>0.05). 3D reconstruction of renal tumors resulted in more accurate dissection of the tumor artery (90.9%) as compared to conventional CTA (81.5%). All the patients had negative surgical margins. There was no significant difference in the estimated glomerular filtration rate (eGFR) before and after surgery between two groups.

Conclusions

3D reconstruction is beneficial for the resection of cT1b renal tumor and tumor-specific feeding arteries in the off-clamp LPN.

A novel RBMX-TFE3 gene fusion in a highly aggressive pediatric renal perivascular epithelioid cell tumor

We report an Xp11 translocation perivascular epithelioid cell tumor (PEComa) with a novel RBMX-TFE3 gene fusion, resulting from a paracentric X chromosome inversion, inv(X)(p11;q26). The neoplasm occurred in an otherwise healthy 12-year-old boy who presented with a large left renal mass with extension into the inferior vena cava. The patient was found to have multiple pulmonary metastases at diagnosis and died of disease 3 months later. The morphology (epithelioid clear cells with alveolar and nested architecture) and immunophenotype (TFE3 and HMB45 strongly positive; actin, desmin, and PAX8 negative) was typical of an Xp11 translocation PEComa; however, TFE3 rearrangement was initially not detected by routine TFE3 break-apart fluorescence in situ hybridization (FISH). Further RNA sequencing revealed a novel RBMX-TFE3 gene fusion, which was subsequently confirmed by fusion assay FISH, using custom design RBMX and TFE3 come-together probes. This report describes a novel TFE3 gene fusion partner, RBMX, in a pediatric renal PEComa patient associated with a fulminant clinical course. As documented in other intrachromosomal Xp11.2 inversions, such as fusions with NONO, RBM10, or GRIPAP1 genes, the TFE3 break-apart might be below the FISH resolution, resulting in a false negative result.

Trifecta Outcomes in Renal Hilar Tumors: A Comparison Between Robotic and Open Partial Nephrectomy

OBJECTIVES

To report a comparative analysis of outcomes in patients who underwent excisions of renal hilar tumors using both open and robotic approaches.

MATERIALS AND METHODS

We retrospectively reviewed robotic and open patients who underwent partial nephrectomy of renal hilar tumors between 2011 and 2016. "Trifecta" was defined as negative surgical margins, no complications, and a glomerular filtration rate (GFR) preservation of ≥90% at last follow-up. Inverse probability of treatment weighting (IPTW) was applied to equilibrate treatment groups, minimize selection bias, and optimize inference on the basis of each patient's clinicodemographic characteristics.

RESULTS

One hundred robotic and 64 open patients had sufficient data for IPTW. After weighting, there were no statistical differences in baseline characteristics between the two groups (p < 0.05). On adjusted analyses, robotic partial nephrectomy (RPN) achieved equivalent rates of trifecta to open surgery (21.1% vs 13.9%, respectively, p = 0.387). There were no differences between robotic and open cohorts for negative margin rates (72.8% vs 90.4%, p = 0.124), absence of complications (68.6% vs 75.2%, p = 0.587), or GFR ≥90% (39.4% vs 21.6%, p = 0.111). The robotic cohort had a shorter mean length of stay (3.8 vs 5.0 days, p = 0.012), and no difference in estimated blood loss (253.3 vs 357.1, p = 0.091) or operating time (199.8 vs 200.4, p = 0.961).

CONCLUSIONS

In our analysis both open and RPN for hilar tumors were equally likely to achieve a low "trifecta" outcome with a shorter mean length of stay in the robotic cohort.

"At-risk" kidney: How surgical factors influence renal functional preservation after partial nephrectomy

OBJECTIVES

To investigate the influence of surgical modifiable factors on chronic kidney disease upstaging in a contemporary cohort of patients with normal and "at-risk" kidneys undergoing partial nephrectomy.

METHODS

We reviewed 778 consecutive patients with (n = 634)/without (n = 144) chronic kidney disease or risk factors for chronic kidney disease in our institutional partial nephrectomy database. Chronic kidney disease upstaging was assessed using glomerular filtration rate measurements preoperatively and at 3-12 months postoperatively. Using a multivariate logistic regression, baseline clinicodemographic factors, and the operative measurements of excisional volume loss and warm and cold ischemia time on rates of chronic kidney disease upstaging were determined. Marginal effects were used to analyze the impact of ischemia time and generate interaction curves.

RESULTS

Chronic kidney disease/risk factors for chronic kidney disease had equivalent rates of chronic kidney disease upstaging as the healthy kidney cohort (31.5% vs 38.2%, P = 0.15). Of the entire cohort, 2.8% were upstaged to stage IV-V chronic kidney disease. Multivariate analysis found a significant association between chronic kidney disease upstaging and excisional volume loss in both cohorts (no chronic kidney disease/risk factors for chronic kidney disease: odds ratio 1.63, P = 0.04; chronic kidney disease/risk factors for chronic kidney disease: odds ratio 1.42, P = 0.001). Only in the chronic kidney disease/risk factors for chronic kidney disease cohort, there was an association between ischemia type/duration and chronic kidney disease upstaging (odds ratio 1.04, P = 0.04). Warm ischemia began to predict an increased risk of chronic kidney disease upstaging at 17.6 min, which became statistically significant at 49 min.

CONCLUSIONS

Chronic kidney disease upstaging is common after partial nephrectomy. Although volume loss unequivocally affects rates of upstaging irrespective of baseline renal function, warm ischemia time disproportionately influences "at-risk" kidneys. Therefore, strong consideration should be given to minimizing volume loss and using cold ischemia when extended clamp times are anticipated in "at-risk" kidneys.

Whole-genome and transcriptome profiling of a metastatic thyroid-like follicular renal cell carcinoma

Thyroid-like follicular renal cell carcinoma (TLFRCC) is a rare cancer with few reports of metastatic disease. Little is known regarding genomic characteristics and therapeutic targets. We present the clinical, pathologic, genomic, and transcriptomic analyses of a case of a 27-yr-old male with TLFRCC who presented initially with bone metastases of unknown primary. Genomic DNA from peripheral blood and metastatic tumor samples were sequenced. A transcriptome of 280 million sequence reads was generated from the same tumor sample. Tumor somatic expression profiles were analyzed to detect aberrant expression. Genomic and transcriptomic data sets were integrated to reveal dysregulation in pathways and identify potential therapeutic targets. Integrative genomic analysis with The Cancer Genome Atlas (TCGA) data set revealed the following outliers in gene expression profiles: CDK6 (81st percentile), MYC (99th percentile), AR (100th percentile), PDGFRA and PDGFRB (99th and 100th percentiles, respectively), and MAP2K2 (86th percentile). The patient received first-line sunitinib to target PDGFRA and PDGFRB and had stable disease for >6 mo, followed by nivolumab upon progression. To the authors’ knowledge, this is the first reported case of comprehensive somatic genomic analyses in a patient with metastatic TLFRCC. Somatic analyses provided molecular confirmation of the primary site of cancer and potential therapeutic strategies in a rare disease with little evidence of efficacy on systemic therapy.

Expanding the Indications of Robotic Partial Nephrectomy for Highly Complex Renal Tumors: Urologists' Perception of the Impact of Hyperaccuracy Three-Dimensional Reconstruction

OBJECTIVES

To assess the role of three-dimensional (3D) reconstruction in aiding preoperative planning for highly complex renal tumors amenable to robotic partial nephrectomy (RPN).

MATERIALS AND METHODS

Computed tomography (CT) scans and respective 3D reconstructions of 20 highly complex renal tumors were displayed to the attendees/urologists of the 6th Techno-Urology Meeting ( www.technourologymeeting.com ). These 20 cases had already undergone RPN performed by a single experienced surgeon. The attendees were asked to watch the videos of the CT scans first, and then the respective 3D reconstructions of 5 of the 20 cases who were randomly selected. A purpose-built questionnaire collected responders' surgical experience and surgical indication (RPN versus nephrectomy) after viewing the CT scan and the respective 3D reconstructions.

RESULTS

Twenty expert urologists, 27 young urologists, and 61 residents (total = 108) participated in the study. Five hundred forty-two views of the cases were obtained. Based on CT scans, RPN was indicated in 256 cases (47.2%). After viewing the respective 3D reconstructions, in 148 cases the responders changed their idea: indication to RPN raised in 404 cases (74.5%) (P < .001). The opinions changed regardless of the surgical experience.

CONCLUSIONS

The findings of this study are encouraging, and they might represent a significant step toward the validation of the use of 3D reconstruction for surgical planning in patients undergoing robotic kidney surgery. The use of this technology might translate into a larger adoption of nephron-sparing approach. Further investigation in this area is warranted to corroborate these findings.

Achieving tumour control when suspecting sinus fat involvement during robot-assisted partial nephrectomy: step-by-step

OBJECTIVES

To report a single expert robotic surgeon's step-by-step surgical technique for achieving local cancer control during robot-assisted PN (RAPN) for T3 tumours.

PATIENTS AND METHODS

Since January 2010 to December 2016, the institutional RAPN database was queried for patients who underwent transperitoneal RAPN performed by a single surgeon for tumours ≤4 mm from the collecting system at preoperative computed tomography (three points on the 'N [Nearness]' R.E.N.A.L. nephrometry-score item) that were pT3a involving sinus fat at final pathology. Baseline characteristics, perioperative and oncological outcomes (particularly positive surgical margins, PSMs), were identified.

RESULTS

Of 1497 masses that underwent RAPN, 512 scored 3 points on the 'N' item of the R.E.N.A.L. nephrometry score assessment. In all, 24 patients had pT3a tumours involving sinus fat at final pathology and represented the analysed cohort. RAPN were performed according to the here described technique. No PSMs were reported. Trifecta achievement was 54.2%. Within a median follow-up of 30 months, two and one patients had recurrence or metastasis, respectively. Two patients died unrelated to renal cancer. Retrospective analysis and limited follow-up represent study limitations.

CONCLUSION

In a selected cohort of patients with renal tumours near the sinus fat at baseline R.E.N.A.L. nephrometry score assessment and confirmed pT3a at final pathology, the described RAPN technique was able to achieve optimal local cancer control.

Bosniak category III renal lesions: likelihood of malignancy based on computed tomography findings

Introduction

Bosniak introduced a classification of renal cysts based on imaging characteristics. Cystic renal changes are categorized determining their risk of malignancy and further management. However, defining the malignancy of category III lesions still remains a challenge and our aim was to evaluate the features of malignancy in computed tomography within this category.

Material and methods

The Vilnius University Hospital Santariškių Klinikos information system was retrospectively searched for computed tomography examinations in which Bosniak category III lesions were reported. Data of genetic disorders and history of malignancy were collected. Longest diameter, location, shape, amount and location of calcification, contrast enhancement of Bosniak category III lesions were evaluated. The relation between collected data and malignancy was estimated.

RESULTS

There were 73 patients with Bosniak category III lesions included and 43 cysts were surgically removed and histologically analyzed. Mean tumor size was significantly lower in malignant lesions. Mean enhancement in arterial and portovenous phase, change of mean enhancement in portovenous and native phases were significantly different between benign and malignant lesions. Significant differences in the contrast enhancement pattern was found: septa and capsular enhancement was detected in 28.6% (n = 12) of cases in malignant lesions, while only 4.8% (n = 2) benign lesions show the same enhancement pattern. Some other features showed tendencies to be more prevalent in malignant lesions, however, no significant differences were found.

Conclusions

The collected data and selected features do not allow us to reliably differentiate Bosniak category III cystic lesions as benign or malignant. Some of the criteria showed some tendencies, however, further studies are required to confirm these findings' potential.

Primary collision renal tumor of papillary renal cell carcinoma within an oncocytoma: emergency presentation of a rare entity

BACKGROUND

The coexistence of an oncocytoma and a papillary renal cell carcinoma (PRCC) in the same neoplastic mass constitute a collision tumor and is an extremely rare entity. Until now, only six incidentally diagnosed cases have been reported, concerning patients older than 65 years.

CASE REPORT

A 57-year-old man was admitted to the Emergency Department with acute pain and anemia, due to renal hematoma following rupture of such a neoplastic collision mass. The patient underwent an emergency nephrectomy, which revealed a 10.6 cm oncocytoma and a 1.3 cm PRCC. He had an uncomplicated postoperative recovery and remained healthy at the 65-month follow-up, the longest of all previous cases.

CONCLUSION

While prognosis appears favorable, the current report shows that these collision tumors may cause emergency and dangerous medical conditions that deserve prompt treatment. HIPPOKRATIA 2017, 21(2): 105-107.

Sonographically Identified Echogenic Renal Masses Up to 1 cm in Size Are So Rarely Malignant They Can Be Safely Ignored

OBJECTIVES

The purpose of this study was to determine whether small echogenic renal masses up to 1 cm in size incidentally detected by sonography are rarely malignant and thus do not need further workup.

METHODS

We reviewed approximately 13,600 reports of all abdominal sonographic examinations performed between November 2001 and October 2007 that identified a small echogenic mass in a kidney. Patients with known malignancy of any kind, tuberous sclerosis, lesions larger than 1.0 cm, lesions with heterogeneous echogenicity, and lesions with posterior ring-down artifacts or posterior acoustic shadowing were excluded. All patients without magnetic resonance imaging or computed tomographic scans that completely characterized the lesions were excluded unless a follow-up study (sonography, magnetic resonance imaging, or contrast-enhanced computed tomography) at least 5 years later was available for comparison to prove that the lesion was benign.

RESULTS

A total of 120 lesions in 111 patients satisfied the inclusion criteria. Lesion sizes were 0 to 5 mm (n = 16) and 6 to 10 mm (n = 104). Of these, 54 lesions were characterized as definitely benign (47 angiomyolipomas and 7 other benign entities: calcifications in stones or within a cyst or calyx and cysts that were either simple on follow-up studies or complicated with hemorrhagic or proteinaceous content). For the remaining 66 lesions, follow-up results after at least 5 years were normal in 24 cases (which meant that the lesion was no longer visible), and the remaining 42 lesions were stable in size. The mean duration of follow-up for these 66 lesions was 7.4 years.

CONCLUSIONS

Small echogenic renal masses up to 1 cm in size that fulfill our study criteria are so likely to be benign that they can be safely ignored.

Multifocal Primary Neoplasms in Kidney Allografts: Evaluation of Two Cases

Renal cell carcinoma (RCC) is the fifth most common malignancy in kidney transplant recipients, with increased risk arising due to immunosuppression. De novo RCC occurrence in kidney allografts is much less common when compared with the native kidneys. Multifocal RCC in allograft kidneys is rarely described. In this report, we discuss two cases of de novo multifocal renal neoplasms in allograft kidneys. Case 1 had three distinct neoplastic lesions of >5 mm, and case 2 had four. Using the World Health Organization 2016 classification of adult renal tumours, case 1 had one clear-cell (cc) RCC (grade 3) and two papillary adenomas; all confined to the kidney. Case 2 had a nodular lesion classified as ccRCC (grade 4) with focal rhabdoid differentiation and some infiltration of renal sinus fat; a cc tubulopapillary RCC; a multilocular cystic renal neoplasm of low malignant potential; and a mucinous tubular and spindle cell carcinoma; the last three all confined to the kidney. This is the first report of mucinous tubular and spindle cell carcinoma in a kidney allograft. When considering multifocal RCC with discordant histology, it is likely that these represent independent tumourigenic events.

[Current patterns of presentation of renal tumors]

The aim of this paper is to describe the epidemiological characteristics, clinical management and pathologic patterns in a population with renal tumors in our institution. Prospective data collection was performed over a period of 4.5 years, from January 2010 to June 2014. A total of 819 cases (796 patients) were treated for renal mass during this period. The mean age was 60.7 years (SD 13.1). There were 553 (69.5%) males (male to female ratio: 2.2: 1). Twenty nine per cent (230 patients) were obese (BMI = 30). The diagnosis was incidental in 653 cases (79.7%), 48.8% presented one or more risk factors, being smoking the most frequent (34%). In 238 patients (29.9%) there was more than one comorbidity; 18% had preoperative creatinine = 1.3 mg/dl. Lesions were = 4 cm (cT1a) in 45% of the patients, and 10.8% (86) had metastases at diagnosis. The lesions were resected in 93.5% and actively monitored in 6.5% (not resected). In surgery treated patients, radical nephrectomy was performed in 51.5% of cases, and nephron sparing surgery in 48.5% of them. The laparoscopic approach was used in 56.2%. The pattern of presentation of renal masses is characterized by incidental diagnosis in early disease stages. Nephron sparing surgery is the first choice in nearly half of patients. Active surveillance has been used in a greater percentage than previously reported.

Metastases to the kidney: a clinicopathological study of 43 cases with an emphasis on deceptive features

AIMS

To review our experience with metastases to the kidney in surgical pathology material.

METHODS AND RESULTS

The clinicopathological features of all metastases to the kidney in surgical pathology cases between May 1987 and May 2013 at our institution were reviewed. Autopsy cases were excluded. Forty-three cases (16 nephrectomies, 25 biopsies, and two fine needle aspirations) were included; the primary malignancy was diagnosed prior to/concurrently with the metastasis in nearly all cases. Common primary sites included the lung, breast, female genital tract, and head and neck; the majority were carcinomas. A primary renal tumour was suspected prior to the pathological diagnosis in 35% of cases. Unusual features included: common unilateral (77%) and unifocal (70%) involvement, lack of other distant organ metastases (37%), >10 years between primary and metastasis diagnoses (19%), lack of a discrete mass (5%), and renal vein extension (19% of resections). The most common dilemma was excluding urothelial or high-grade renal cell carcinoma; however, metastases from the thyroid commonly mimicked low-grade renal cell carcinomas.

CONCLUSIONS

In surgical pathology material, metastases to the kidney most commonly present as solitary unilateral masses, and in a substantial subset of cases mimic a primary renal tumour.

Emergency embolization of actively bleeding renal angiomyolipoma in a patient of tuberous sclerosis

Renal angiomyolipoma is a benign hamartomatous lesion which contains varying proportions of abnormal blood vessels along with muscle and fat component. Tuberous sclerosis predisposes to angiomyolipoma, and when associated, the lesion is often large with increased risk of hemorrhage and complications. When this occurs, transarterial embolization and surgery are the treatment options. Such a patient presented to us with acute onset of symptoms, and on account of severe anemia with active bleeding, transarterial embolization was performed. This was followed by elective nephrectomy without any complications. We present the imaging aspects of tuberous sclerosis and emphasize role of interventional radiology in this case.

Establishment of an ASPL-TFE3 renal cell carcinoma cell line (S-TFE)

Xp11 translocation renal cell carcinoma is a rare disease diagnosed in children and adolescents in the advanced stage with an aggressive clinical course. Various gene fusions including the transcription factor E3 (TFE3) gene located on chromosome X cause the tumor. We established an Xp11 translocation renal cell carcinoma cell line from a renal tumor in a 18-y-old Japanese female and named it "S-TFE." The cell line and its xenograft demonstrated definite gene fusion including TFE3. They showed strong nuclear staining for TFE3 in immunohistochemistry, TFE3 gene rearrangement in dual-color, break-apart FISH analysis and ASPL-TFE3 type 1 fusion transcripts detected by RT-PCR and direct DNA sequencing. Although many renal cell carcinoma cell lines have been established and investigated, only a few cell lines are recognized as Xp11.2 translocation carcinoma. S-TFE will be useful to examine the characteristics and drug susceptibility of Xp11 translocation renal cell carcinoma.

Radio-frequency ablation helps preserve nephrons in salvage of failed microwave ablation for a renal cancer in a solitary kidney

Recurrent tumors after renal ablative therapy present a challenge for clinicians. New ablative modalities, including microwave ablation (MWA), have very limited experience in methods of retreating ablation failures. Additionally, in MWA, no long-term outcomes have been reported. In patients having local tumor recurrence, options for surveillance or surgical salvage must be assessed. We present a case to help assess radio-frequency ablation (RFA) for salvage of failed MWA. We report a 63-year-old male with a 4.33-cm renal mass in a solitary kidney undergoing laparoscopic MWA with simultaneous peripheral fiber-optic thermometry (Lumasense, Santa Clara, CA, USA) as primary treatment. Follow-up contrast-enhanced computed tomography (CT) scan was performed at 1 and 4.3 months post-op with failure occurring at 4.3 months as evidenced by persistent enhancement. Subsequently, a laparoscopic RFA (LRFA) with simultaneous peripheral fiber-optic thermometry was performed as salvage therapy. Clinical and radiological follow-up with a contrast-enhanced CT scan at 1 and 11 months post-RFA showed no evidence of disease or enhancement. Creatinine values pre-MWA, post-MWA, and post-RFA were 1.01, 1.14, and 1.17 mg/ml, respectively. This represents a 15% decrease in estimated glomerular filtration rate (eGFR) (79 to 67 ml/min) post-MWA and no change in eGFR post-RFA. Local kidney tumor recurrence often requires additional therapy and a careful decisionmaking process. It is desirable not only to preserve kidney function in patients with a solitary kidney or chronic renal insufficiency, but also to achieve cancer control. We show the feasibility of RFA for salvage treatment of local recurrence of a T1b tumor in a solitary kidney post-MWA.

Follow-up for Clinically Localized Renal Neoplasms: AUA Guideline

PURPOSE

The purpose of this guideline is to provide a clinical framework for follow-up of clinically localized renal neoplasms undergoing active surveillance, or following definitive therapy.

MATERIALS AND METHODS

A systematic literature review identified published articles in the English literature between January 1999 and 2011 relevant to key questions specified by the Panel related to kidney neoplasms and their follow-up (imaging, renal function, markers, biopsy, prognosis). Study designs consisting of clinical trials (randomized or not), observational studies (cohort, case-control, case series) and systematic reviews were included.

RESULTS

Guideline statements provided guidance for ongoing evaluation of renal function, usefulness of renal biopsy, timing/type of radiographic imaging and formulation of future research initiatives. A lack of studies precluded risk stratification beyond tumor staging; therefore, for the purposes of postoperative surveillance guidelines, patients with localized renal cancers were grouped into strata of low- and moderate- to high-risk for disease recurrence based on pathological tumor stage.

CONCLUSIONS

Evaluation for patients on active surveillance and following definitive therapy for renal neoplasms should include physical examination, renal function, serum studies and imaging and should be tailored according to recurrence risk, comorbidities and monitoring for treatment sequelae. Expert opinion determined a judicious course of monitoring/surveillance that may change in intensity as surgical/ablative therapies evolve, renal biopsy accuracy improves and more long-term follow-up data are collected. The beneficial impact of careful follow-up will also need critical evaluation as further study is completed.

High temporal resolution 3D gadolinium-enhanced dynamic MR imaging of renal tumors with pharmacokinetic modeling: preliminary observations

PURPOSE

To assess dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) tracer pharmacokinetic parameters obtained with Generalized Kinetic Model (GKM) and extended Shutter Speed Model (SSM2) in renal tumors stratified by histologic subtypes.

MATERIALS AND METHODS

In all, 24 patients with renal tumors were imaged at 1.5 T utilizing DCE-MRI with high temporal resolution (1.2 sec/temporal frame) prior to surgery. Tracer kinetic analysis was performed for the entire tumor using individualized aortic input function. GKM and SSM2 were employed to generate transfer constant (K(trans)), plasma volume, and interstitial volume. These parameters, and ΔK(trans) (K(trans)SSM2 - K(trans)GKM) were compared between tumors stratified by histologic subtype.

RESULTS

There were 25 renal tumors: 15 clear cell, 4 papillary, 3 chromophobe, and 3 oncocytoma/oncocytic subtype. K(trans)GKM was significantly higher in chromophobe compared to other subtypes (P < 0.01). Using K(trans)GKM > 1.0 min(-1), chromophobe were diagnosed with 100% sensitivity and 90.9% specificity. K(trans)SSM2 was higher than K(trans)GKM for all renal tumors except for all chromophobe and two clear cell subtype. Using K(trans)GKM > 1.0 min(-1) and Δ K(trans) < 0, chromophobe could be discriminated from other lesions with 100% accuracy.

CONCLUSION

K(trans) obtained with GKM and SSM2 analysis can potentially discriminate chromophobe from other renal lesions with high accuracy.

Renal primitive malignant tumor with endocrine activity

OBJECTIVE

To report a hypertensive and systematically pigmented female with primitive neuroectodermal tumors.

CLINICAL PRESENTATION AND INTERVENTION

A female patient presented with a complaint of right flank pain. She had a right renal space-occupying lesion, underwent right radical nephrectomy, and returned to normotensive postoperatively. The pathological examination identified typical primitive neuroectodermal tumor histology. During a 60-month follow-up period, she remained normotensive and demonstrated normal renal and adrenal functions.

CONCLUSION

Early diagnosis and definitive surgery led to the patient's long-term survival.

Successful staged management of simultaneous abdominal aortic aneurysm and renal tumor: the novel minimally invasive treatment with endovascular aneurysm repair and retroperitoneal laparoscopic radical nephrectomy in an elderly and high-risk case

The association between abdominal aortic aneurysm (AAA) and renal tumor is becoming more frequent, and the increasing incidence of this synchronous diseases raised questions about the procedures of treatment. In most of the previous cases, open nephrectomy and AAA surgery have been reported, however in high risk and elderly patients, the procedure is life threatening. We present a successful staged treatment of AAA and renal tumor using novel minimally invasive treatment with endovascular aneurysm repair and retroperitoneal laparoscopic radical nephrectomy in an elderly and high-risk case.

Solitary fibrous tumor of the kidney: a case report and review of the literature

A solitary fibrous tumor (SFT) is an unusual spindle cell neoplasm that usually occurs in the pleura but has recently been described in diverse extrapleural sites. Urogenital localization is rare, and only 19 cases of SFT of the kidney have been described. We report a case of a large SFT clinically thought to be renal cell carcinoma arising in the kidney of a 70-year-old man. The tumor was well circumscribed and composed of a mixture of spindle cells and dense collagenous bands, with areas of necrosis or cystic changes noted macroscopically and microscopically. Immunohistochemical studies revealed reactivity for CD34, CD99, and Bcl-2 protein, with no staining for keratin, S-100 protein, or muscle markers, confirming the diagnosis of SFT. This tumor is benign in up to 90% of cases. The immunohistochemical study is the key to diagnosis.