Metanephric Adenoma: A Case Report of a Rare Epithelial Renal Tumor.

Metanephric adenoma (MA) is a rare embryonal epithelial tumor that is often diagnosed incidentally. A definitive diagnosis can only be made postoperatively based on the pathological findings. This case report discusses the rare occurrence of a metanephric adenoma, the symptoms it can present with, and the diagnosis, treatment, and immunological staining needed to differentiate metanephric adenoma from other types of renal tumors. In this study, a 37-year-old female presented to the emergency room for vague right lower quadrant pain (RLQ) and underwent imaging that showed a lesion on the lower pole of the left kidney. A subsequent biopsy of the lesion showed a low-grade renal epithelial neoplasm favoring metanephric adenoma. The patient successfully underwent a left partial nephrectomy to remove the tumor, which required no further treatment after resection. Due to the rarity of the tumor, it requires immunohistology to differentiate from other renal tumors such as Wilm's tumor and renal cell carcinoma. This case report aims to recognize proper workup, diagnosis, and treatment to achieve a positive outcome in the setting of this rare tumor.

Descending Colon Metastasis of Renal Cell Carcinoma: An Unusual Site of Metastasis.

Renal cell carcinoma (RCC) has a high metastatic potential. While metastasis to common sites like the lungs, liver, bones, and brain is well-documented, metastasis to the colon, particularly the descending colon, remains an uncommon occurrence. When RCC does metastasize to the gastrointestinal tract, it commonly spreads to the small bowel and stomach. There are few cases reported in literature involving RCC metastasis to the colon. The commonly affected areas within the colon include the rectosigmoid colon, splenic flexure, and transverse colon. We describe an 87-year-old male with a history of stage III RCC diagnosed three years ago, followed by left-sided nephroureterectomy, partial adrenalectomy, and perinephric lymph node dissection. He presented to the emergency department (ED) with melena and generalized abdominal pain for one week. Stool occult blood was positive. Computed tomography (CT) of the abdomen was significant for stable postsurgical changes related to prior left nephrectomy and colonic mass at the proximal descending colon. A colonoscopy revealed a necrotic appearing friable mass in the descending colon. The pathology of the mass revealed proliferated atypical cells positive for paired box 8 (PAX8), a cluster of differentiation 10 (CD10), RCC, and pan-cytokeratin and negative for caudal-type homeobox 2 (CDX2), thyroid transcription factor-1 (TTF-1), and a cluster of differentiation 68 (CD68), consistent with metastatic RCC.

Papillary renal neoplasm with reverse polarity has low frequency of alterations in chromosomes 7, 17, and Y.

In papillary renal neoplasm with reverse polarity (PRNRP), the status of chromosomal copy number alterations, especially chromosomes 7/17 gain and chromosome Y loss, has remained controversial. In the literatures, there is a discrepancy among the results of chromosomal alteration in PRNRP depending on the analytical methods. Here, we comprehensively analyzed the status of chromosomal abnormalities in PRNRP. Nineteen PRNRP cases were analyzed by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC), five of which were additionally subjected to array-based comparative genomic hybridization (aCGH) analysis. Fifteen cases of PRCC were used as controls. From the aCGH results, no genome copy number abnormalities were found in the five PRNRP cases. By FISH, numbers of nuclei with abnormal chromosomal signals in PRNRP (centromere 7 gain: 11-21% of nuclei, centromere 17 gain: 11% of nuclei, centromere Y loss: 14-31% of nuclei) were similar to those in non-neoplastic tubular cells (centromere 7 gain: 11-15% of nuclei, centromere 17 gain: 12-15% of nuclei, centromere Y loss: 13-45% of nuclei). c-MET immunohistochemical overexpression, a substitute marker for chromosome 7 trisomy, was observed in 0 of 19 PRNRP cases, consistent with the analyses by aCGH and NGS regarding chromosome 7 gain. Taken together, the frequency of chromosomal alterations in PRNRP is similar to that in non-neoplastic tubular cells, and lower than that in PRCC. Our data suggest that PRNRP has a different tumorigenesis and is a distinct entity from PRCC.

Partial nephrectomy after a period of active surveillance: Are perioperative and pathology outcomes worsened compared to immediate surgery?

INTRODUCTION: Active surveillance (AS) is a viable strategy for managing small renal masses (SRMs) in lieu of immediate surgery, but concerns persist regarding its impact on delayed partial nephrectomy (PN) outcomes. We aimed to compare perioperative and pathological outcomes of patients initially on AS for SRMs, later undergoing PN, against those undergoing immediate PN. MATERIALS AND METHODS: Data were extracted from a prospective institutional database (January 2018-September 2023) for patients with cT1a renal masses. Only malignancies confirmed at final pathology were included. Baseline patient and tumor characteristics and the time from AS enrollment to PN were recorded. Surgical, renal functional, and final pathology outcomes were analyzed, including histology, tumor size, pT stage, upstaging rate, and positive surgical margins. Predictors of upstaging were identified using logistic regression models. RESULTS: Analysis included 356 patients: 307 immediate PN and 49 deferred PN after a median of 18 months in AS. Groups had comparable baseline characteristics; no significant differences emerged in surgical and postoperative outcomes. Final pathology revealed no significant disparities in tumor size, histology, positive margins, or upstaging, though pT stage distribution differed (2.4 % versus 4.3 % for pT3a, immediate versus deferred, p = 0.04). Univariable analysis identified RENAL Score (OR 1.29, 95 % C.I. 1.09-1.53, p = 0.003) and clinical tumor size (OR 1.16, 95 % C.I. 1.10-1.22, p < 0.01) as upstaging predictors, confirmed by multivariable analysis (p < 0.01). CONCLUSION: Our comparative analysis found no worsened perioperative or adverse pathological outcomes in patients with deferred PN, supporting the safety of this approach in managing SRMs, at least as an initial option.

Clinicopathological characteristics and typing of multilocular cystic renal neoplasm of low malignant potential.

BACKGROUND: Up until now, no research has been reported on the association between the clinical growth rate of multilocular cystic renal neoplasm of low malignant potential (MCRNLMP) and computed tomography (CT) imaging characteristics. Our study sought to examine the correlation between them, with the objective of distinguishing unique features of MCRNLMP from renal cysts and exploring effective management strategies. AIM: To investigate optimal management strategies of MCRNLMP. METHODS: We retrospectively collected and analyzed data from 1520 patients, comprising 1444 with renal cysts and 76 with MCRNLMP, who underwent renal cyst decompression, radical nephrectomy, or nephron-sparing surgery for renal cystic disease between January 2013 and December 2021 at our institution. Detection of MCRNLMP utilized the Bosniak classification for imaging and the 2016 World Health Organization criteria for clinical pathology. RESULTS: Our meticulous exploration has revealed compelling findings on the occurrence of MCRNLMP. Precisely, it comprises 1.48% of all cases involving simple renal cysts, 5.26% of those with complex renal cysts, and a noteworthy 12.11% of renal tumors coexisting with renal cysts, indicating a statistically significant difference (P = 0.001). Moreover, MCRNLMP constituted a significant 22.37% of the patient population whose cysts demonstrated a rapid growth rate of ≥ 2.0 cm/year, whereas it only represented 0.66% among those with a growth rate below 2.0 cm/year. Of the 76 MCRNLMP cases studied, none of the nine patients who underwent subsequent nephron-sparing surgery or radical nephrectomy following renal cyst decompression experienced recurrence or metastasis. In the remaining 67 patients, who were actively monitored over a 3-year postoperative period, only one showed suspicious recurrence on CT scans. CONCLUSION: MCRNLMP can be tentatively identified and categorized into three types based on CT scanning and growth rate indicators. In treating MCRNLMP, partial nephrectomy is preferred, while radical nephrectomy should be minimized. After surgery, active monitoring is advisable to prevent unnecessary nephrectomy.

Assessing the perioperative outcomes of abdominal drain omission after robot-assisted partial nephrectomy.

The study aimed to evaluate the impact of abdominal drain placement (vs. omission) on perioperative outcomes of robot-assisted partial nephrectomy (RAPN), focusing on complications, time to canalization, deambulation, and pain management. A prospectively-maintained institutional database was queried to get data of patients who underwent RAPN for renal masses between January 2018 and May 2023 at our Institution. Baseline, surgical, and postoperative data were collected. Retrieved patients were stratified based upon placement of abdominal drain (Y/N). Descriptive analyses comparing the two groups were conducted as appropriate.77 After adjusting for potential confounders, a logistic regression analysis was conducted to evaluate significant predictors of any grade and "major" complications. 342 patients were included: 192 patients in the "drain group" versus 150 patients in the "no-drain" group. Renal masses were larger (p < 0.001) and at higher complexity (RENAL score, p = 0.01), in the drain group. Procedures in the drain group had statistically significantly longer operative time, ischemia time, and higher blood loss (all p-values < 0.001). The urinary collecting system was more likely involved compared to the no-drain group (p = 0.01). At multivariate analysis, abdominal drainage was not a significant predictor of any grade (OR 0.79, 95%CI 0.33-1.87) and major postoperative complications (OR 3.62, 95%CI 0.53-9.68). Patients in the drain group experienced a statistically significantly higher hemoglobin drop (p < 0.01). Moreover, they exhibited statistically significant higher paracetamol consumption (p < 0.001) and need for additional opioids (p = 0.02). In summary, the study results suggest the safety of omitting drain placement and remark on the need for personalized decision-making, which considers patient and procedural factors.

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.

Alpha-methyl CoA racemase (AMACR) reactivity across the spectrum of clear cell renal cell neoplasms.

a-Methylacyl coenzyme A racemase (AMACR) is traditionally considered to be a marker of papillary renal cell carcinoma. However, AMACR expression can be seen in other renal tumors. The aim of this study was to investigate AMACR immunoreactivity within the spectrum of clear cell renal cell neoplasms. Fifty-three clear cell renal epithelial tumors were used in assembling the following four cohorts: low grade (LG) clear cell renal cell carcinoma (CCRCC), high grade (HG) CCRCC, CCRCC with cystic changes, and multilocular cystic renal neoplasm of low malignant potential (MCRNLMP). Representative blocks were stained for AMACR, using two different clones (SP52 and OV-TL12/30). There were at least some AMACR immunoreactivity in 77.8 % and 68.9 % of CCRCCs (using SP52 and OV-TL12/30 clone, respectively). Moderate to strong positivity, or positivity in more than one third of the tumor (even weak in intensity) was detected in 46.7 % of CCRCCs using SP52 and in 48.9 % of CCRCC using OV-TL12/30 clone. The highest AMACR reactivity was observed in HG CCRCC (60 % by SP52 and 66.7 % by OV-TL12/30). Strong and diffuse AMACR positivity was detected in 8.9 % of all CCRCCs. AMACR immunoreactivity in MCRNLMP was 37.5 % (SP52 clone) and 25 % (OV-TL12/30 clone). We demonstrated relatively high expression rate of AMACR in CCRCC, while very variable in intensity and distribution. This finding may have diagnostic implications especially in limited samples (i.e., core biopsies), as AMACR positivity does not exclude the diagnosis of CCRCC.

Papillary renal neoplasm with reverse polarity is biologically and clinically distinct from eosinophilic papillary renal cell carcinoma.

Papillary renal neoplasm with reverse polarity (PRNRP) is a recently described indolent entity with distinct features and its recognition from other oncocytic/eosinophilic papillary renal cell carcinoma (ePRCC) has important prognostic implications. ABCC2, a renal drug transporter, is overexpressed in aggressive PRCCs. In this study, we compared the clinicopathological parameters and the biological ABCC2 expression between PRNRP and ePRCC. PRNRP (n = 8) and ePRCC (n = 21) cases were selected from resection specimens and corresponding clinicopathological data were collected. ABCC2 immunohistochemical (IHC) staining was performed and ABCC2 staining patterns were classified as negative, cytoplasmic, and brush-border. RNA in-situ hybridization (ISH) was used to assess ABCC2 transcript levels. All eight PRNRP cases had weak cytoplasmic ABCC2 IHC reactivity; however, they showed no detectable ABCC2 transcripts on RNA ISH. In comparison, 76% (16/21) of ePRCCs showed ABCC2 IHC brush-border expression and significantly higher ABCC2 RNA ISH transcript levels (p < 0.001). Additionally, the ePRCC group showed a significantly larger tumor size (p = 0.004), higher WHO/ISUP grade (p < 0.001), and stage (p = 0.044). None of the PRNRP cases showed disease progression, while 9.5% (2/21) ePRCCs had disease progression. PRNRP is clinically and biologically distinct from ePRCC. Hence, it is crucial to differentiate between these two entities, particularly in needle core biopsies.

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.

Non-coding RNA and gene expression analyses of papillary renal neoplasm with reverse polarity (PRNRP) reveal distinct pathological mechanisms from other renal neoplasms.

Papillary renal neoplasm with reversed polarity (PRNRP) is a recently described rare renal neoplasm. Traditionally, it was considered a variant of papillary renal cell carcinoma (PRCC). However, several studies reported significant differences between PRNRP and PRCC in terms of clinical, morphological, immunohistochemical and molecular features. Nonetheless, PRNRP remains a poorly understood entity. We used microarray analysis to elucidate the non-coding RNA (ncRNA) and gene expression profiles of 10 PRNRP cases and compared them with other renal neoplasms. Unsupervised cluster analysis showed that PRNRP had distinct expression profiles from either clear cell renal cell carcinoma (ccRCC) or PRCC cases at the level of ncRNA but were less distinct at the level of gene expression. An integrated omic approach determined miRNA:gene interactions that distinguished PRNRP from PRCC and we validated 10 differentially expressed miRNAs and six genes by quantitative RT-PCR. We found that levels of the miRNAs, miR-148a, miR-375 and miR-429, were up-regulated in PRNRP cases compared to ccRCC and PRCC. miRNA target genes, including KRAS and VEGFA oncogenes, and CXCL8, which regulates VEGFA, were also differentially expressed between renal neoplasms. Gene set enrichment analysis (GSEA) determined different activation of metabolic pathways between PRNRP and PRCC cases. Overall, this study is by far the largest molecular study of PRNRP cases and the first to investigate either ncRNA expression or their gene expression by microarray assays.

MED15::TFE3 fusion renal cell carcinoma with extensive cystic change: A clinicopathologic and molecular genetic study of 2 cases, with an emphasis on differential diagnosis.

OBJECTIVES: TFE3-rearranged renal cell carcinomas (RCCs) harbor gene fusions between TFE3 and 1 of many partner genes. MED15::TFE3 fusion RCC is rare, often cystic, and easily misdiagnosed. METHODS: This study aimed to characterize 2 cases of MED15::TFE3 fusion RCC with extensive cystic change using fluorescence in situ hybridization and targeted RNA sequencing. RESULTS: Both patients were young adult women aged 29 and 35 years. Radiologically, both presented with a cystic Bosniak category II renal lesion. The cysts measured 9.3 cm and 4.8 cm in greatest dimension. Both patients underwent cyst enucleation, and neither had tumor recurrence or metastasis at 26 and 6 months of follow-up, respectively. Microscopically, both tumors were entirely cystic, with thick, fibrous cystic walls lined by small clusters of cells with clear to eosinophilic cytoplasm and uniform, round nuclei with inconspicuous nucleoli. There were also small aggregations of similar clear cells within the cystic walls. Foci of basement membrane-like material depositions were noted in 1 case; calcifications were observed in both cases. Both cases demonstrated nuclear positivity for PAX8 and TFE3 and cytoplasmic staining for Melan-A; HMB45, CAIX, and CK7 were negative. Fluorescence in situ hybridization revealed that both tumors were positive for TFE3 rearrangements. RNA sequencing identified MED15::TFE3 gene fusions in both cases. CONCLUSIONS: The main differential diagnosis of MED15::TFE3 fusion RCC includes multilocular cystic renal neoplasm of low malignant potential and atypical renal cysts. Molecular confirmation of TFE3 fusion is essential for establishing the correct diagnosis.

Postoperative outcomes of transperitoneal versus retroperitoneal robotic partial nephrectomy: a propensity-score matched comparison focused on patient mobilization, return to bowel function, and pain.

Literature meta-analyses comparing transperitoneal versus retroperitoneal approach to robotic partial nephrectomy (RPN) suggested some advantages favoring retroperitoneoscopy. Unfortunately, patient-centered data about mobilization, canalization, pain, and use of painkillers remained anecdotally reported. The present analysis aimed to compare transperitoneal versus retroperitoneal RPN focusing on such outcomes. Study data including baseline variables, perioperative, and postoperative outcomes of interest were retrieved from prospectively maintained institutional database (Jan 2018-May 2023) and compared between treatment groups (transperitoneal versus retroperitoneal). Propensity score matching was performed using the STATA command psmatch2 considering age, sex, body mass index, previous abdominal surgery, RENAL score, tumor size and location, and cT stage. The logit of propensity score was used for matching, with a 1:1 nearest neighbor algorithm, without replacement (caliper of 0.001). A total of 442 patients were included in the unmatched analysis: 330 underwent transperitoneal RPN 112 retroperitoneal RPN. After propensity score, 98 patients who underwent retroperitoneal RPN were matched with 98 patients who underwent transperitoneal RPN. Matched cohorts had comparable patients' demographics and tumor features. We found similarity between the two laparoscopic accesses in all outcomes but in blood loss, which favored retroperitoneoscopic RPN (median 150 (IQR 100-300) versus 100 (IQR 0-100) ml, p = 0.03). No differences were found in terms of time to mobilization with ambulation, return to complete bowel function, postoperative pain, but higher painkillers consumption was reported after transperitoneal RPN (p < 0.004). The present study compared the transperitoneal versus the retroperitoneal approach to RPN, confirming the similarity between the two approaches in all perioperative outcomes. Based on our findings, the choice of the surgical approach to RPN may remain something that the surgeon decides.

Irreversible electroporation: Beyond the limits of tumor ablation.

Irreversible Electroporation (IRE) is a non-thermal tumor ablation technique. High-voltage electrical pulses are applied between pairs of electrodes inserted around and/or inside a tumor. The generated electric current induces the creation of nanopores in the cell membrane, triggering apoptosis. As a result, IRE can be safely used in areas near delicate vascular structures where other thermal ablation methods are contraindicated. Currently, IRE has demonstrated to be a successful ablation technique for pancreatic, renal, and liver tumors and is widely used as a focal therapeutic option for prostate cancer. The need for specific anesthetic management and accurate parallel placement of multiple electrodes entails a high level of complexity and great expertise from the interventional team is required. Nevertheless, IRE is a very promising technique with a remarkable systemic immunological capability and may impact on distant metastases (abscopal effect).

[Papillary renal neoplasm with reverse polarity]. / Papillyarnaya opukhol' pochki s reversivnoi polyarnost'yu yader.

Papillary renal neoplasm with reverse polarity is a rare subtype of papillary renal cell tumors with unique morphology, specific molecular features and good prognosis. The article presents literature data and describes our own observation of a papillary kidney tumor with reverse nuclear polarity in a 73-year-old patient. The difficulties of preoperative diagnosis of a tumor are shown, histological and immunohistochemical criteria for diagnosis and differential diagnosis of this tumor with other kidney tumors are presented. This rare case is of interest for both pathologists and clinicians.

Electroporación irreversible: ampliando las fronteras de la ablación / Irreversible electroporation: Beyond the limits of tumor ablation

La electroporación irreversible o IRE (irreversible electroporation) es una técnica de ablación tumoral no térmica basada en la aplicación de pulsos eléctricos de alto voltaje entre pares de agujas insertadas alrededor de un tumor. La corriente generada favorece la creación de nanoporos en la membrana plasmática, desencadenando la apoptosis. Por ello, la IRE puede utilizarse de manera segura en localizaciones cercanas a estructuras vasculares delicadas, contraindicadas para el resto de técnicas termoablativas. Actualmente la IRE se emplea con éxito para la ablación de tumores en páncreas, riñón e hígado y, de manera muy extendida, como opción terapéutica focal para el cáncer de próstata. La necesidad de un manejo anestésico específico y la colocación precisa y en paralelo de múltiples agujas implican un alto nivel de complejidad, siendo necesaria una gran experiencia del equipo intervencionista. No obstante, se trata de una técnica muy prometedora con una gran capacidad inmunológica sistémica que puede provocar un efecto a distancia del tumor tratado (efecto abscopal).(AU)

Irreversible electroporation (IRE) is a non-thermal tumor ablation technique. High-voltage electrical pulses are applied between pairs of electrodes inserted around and/or inside a tumor. The generated electric current induces the creation of nanopores in the cell membrane, triggering apoptosis. As a result, IRE can be safely used in areas near delicate vascular structures where other thermal ablation methods are contraindicated. Currently, IRE has demonstrated to be a successful ablation technique for pancreatic, renal, and liver tumors and is widely used as a focal therapeutic option for prostate cancer. The need for specific anesthetic management and accurate parallel placement of multiple electrodes entails a high level of complexity and great expertise from the interventional team is required. Nevertheless, IRE is a very promising technique with a remarkable systemic immunological capability and may impact on distant metastases (abscopal effect).(AU)

Robot-assisted excision of hemangioma of the right renal vein.

Hemangiomas, benign vascular masses, occasionally occur in the kidneys, presenting as rare, small, unilateral, and solitary growths. Venous hemangiomas, a renal subtype, are atypical. While clinically nonspecific, they are typically asymptomatic and may be incidentally discovered during unrelated clinical workups. Diagnosing renal hemangioma preoperatively is challenging due to rarity, lacking standard radiographic criteria, and poor differentiation from aggressive renal neoplasms on contrast-enhanced imaging. These tumors commonly follow a benign course, with no documented recurrence. This video article showcases the robot-assisted excision of a renal vein hemangioma, addressing the expertise needed in managing this uncommon condition robotically.

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.

Elevation of cancer antigen 15-3 owing to oncocytic renal neoplasm in a patient without evidence of breast cancer recurrence on follow-up: a case report.

BACKGROUND: Cancer antigen 15-3 is a protein that clinicians commonly measure to monitor outcomes and response to treatment in patients with breast cancer. However, cancer antigen 15-3 can also be elevated in other, benign and malignant conditions. CASE PRESENTATION: A 73-year-old White woman with history of breast cancer presented to her primary care physician with right hip pain, and laboratory testing revealed elevated cancer antigen 15-3. Further workup with radiographic imaging revealed a large mass in her right kidney. The renal mass was subsequently removed, and the cancer antigen 15-3 level returned to normal. CONCLUSIONS: Elevation of cancer antigen 15-3 owing to causes other than breast cancer recurrence can be a potential diagnostic pitfall during a patient's follow-up. It is important for clinicians to be aware of the limitations of cancer markers and to utilize a combination of diagnostic tests for patient evaluation.

Cytomorphology of papillary renal neoplasm with reverse polarity.

Papillary renal neoplasm with reverse nuclear polarity (PRNRP) is an emerging oncocytic renal tumor. Cytomorphologic features of this tumor have not been described in the literature before. The objective of this study was to review the cytomorphology of a case PRNRP and compare with cytomorphologic features of papillary renal cell carcinomas (pRCCs) reported in the literature. 1 case of core needle biopsy (CNB) with touch preparation (TP) of a renal mass diagnosed as PRNRP was reviewed retrospectively. Clinical presentation, cytomorphologic features, ancillary tests and histopathology results were analyzed. The touch preparation was cellular and showed tight 3-D clusters of cuboidal epithelial cells with variable presence of fibrovascular cores (FC), granular eosinophilic cytoplasm, round apically located grade 1 nuclei compared to cases of pRCC that consistently showed presence of FCs lined by cuboidal to columnar epithelial cells with variable degree of cytologic atypia. Features characteristic of pRCC like foamy macrophages, hemosiderin laden macrophages, nuclear grooves or psammoma bodies were not present. No necrosis or mitosis were identified. By immunohistochemistry (IHC) the tumor cells were positive for cytokeratin 7, GATA-3 and AMACR (focal) and negative for CA-IX, CD117 and vimentin. Cytomorphologic features of PRNRP are unique and characterized by tight 3-D clusters (with or without FCs) of cuboidal cells with small round apically located nuclei and finely granular oncocytic cytoplasm. Specific diagnosis of PRNRP on cytology or CNB is feasible along with use of ancillary tests IHC and /or molecular tests.