Peripelvic Fat Research Articles

Renal Pelvic Urothelial Carcinoma With Invasion Into Renal Medulla Can Be Redefined as pT2 to Improve Correlation With Survival

According to the American Joint Cancer Committee, pT3 renal pelvic carcinoma is defined as tumor invading the renal parenchyma and/or peripelvic fat and is the largest pT category, with notable survival heterogeneity. Anatomical landmarks within the renal pelvis can be difficult to discern. Using glomeruli as a boundary to differentiate renal medulla invasion from renal cortex invasion, this study aimed to compare patient survival of pT3 renal pelvic urothelial carcinoma on the basis of the extent of renal parenchyma invasion and, thereafter, determine whether redefining pT2 and pT3 improves pT correlation with survival. Cases with primary renal pelvic urothelial carcinoma were identified through a review of pathology reports from nephroureterectomies completed at our institution from 2010 to 2019 (n = 145). Tumors were stratified by pT, pN, lymphovascular invasion, and invasion of the renal medulla versus invasion of the renal cortex and/or peripelvic fat. Overall survival between groups was compared using Kaplan-Meier survival models and Cox regression multivariate analysis. pT2 and pT3 tumors had similar 5-year overall survival, with multivariate analysis demonstrating an overlap between hazard ratios (HRs) for pT2 (HR, 2.20; 95% CI, 0.70-6.95) and pT3 (HR, 3.15; 95% CI, 1.63-6.09). pT3 tumors with peripelvic fat and/or renal cortex invasion had a 3.25-fold worse prognosis than pT3 tumors with renal medulla invasion alone. Furthermore, pT2 and pT3 tumors with only renal medulla invasion had similar overall survival, whereas pT3 tumors with peripelvic fat and/or renal cortex invasion had a worse prognosis (P = .00036). Reclassifying pT3 tumors with only renal medulla invasion as pT2 yielded greater separation between survival curves and HR. Thus, we recommend redefining pT2 renal pelvic carcinoma to include renal medulla invasion and restricting pT3 to peripelvic fat and/or renal cortex invasion to improve the prognostic accuracy of pT classification.

Reclassifying pT3 renal pelvic urothelial carcinoma with renal parenchyma invasion to pT2 improves correlation with overall survival

The American Joint Cancer Committee pT categorization in renal pelvic carcinoma defines pT3 as invasion of renal parenchyma, invasion of peripelvic fat, or both. However, survival heterogeneity within the pT3 category has been demonstrated. This investigation sought to compare survival between pT categories of renal pelvic urothelial carcinoma and identify modifications to improve correlation with survival. Pathology reports from nephroureterectomies performed at our institution from 2010 to 2019 were analyzed to identify primary renal pelvic urothelial carcinoma (n=146). Tumors were stratified based on pT, pN, and invasion of renal parenchyma vs invasion of peripelvic fat with or without renal parenchyma invasion. Kaplan-Meier survival curves and Cox regression multivariate analysis were used to compare overall survival between groups. Similar survival curves were observed for pT2 and pT3 tumors. Multivariate analysis confirmed overlapping hazard ratios (HRs) for pT2 (HR=2.64, 95% confidence interval [CI] = 0.69, 10.06)and pT3 (HR=4.42, 95% CI = 2.08, 9.37). pT3 tumors with peripelvic fat invasion, regardless of renal parenchyma involvement, had a 3.3-fold worse overall survival than pT3 tumors with only renal parenchyma involvement. Additionally, pT3 tumors with only renal parenchyma invasion had similar survival compared to pT2, while pT3 tumors with peripelvic fat invasion had worse overall survival (p=0.00091). Reclassifying renal parenchyma invasion as pT2 yielded greater survival curve separation and greater difference in HRs. For renal pelvic urothelial carcinoma, modifying the pT3 category to only include tumors with peripelvic fat invasion and expanding the pT2 category to include renal parenchyma invasion may improve pT correlation with overall survival.

Prognostic Impact of pT3 Subclassification in a Multicentre Cohort of Patients with Urothelial Carcinoma of the Renal Pelvicalyceal System Undergoing Radical Nephroureterectomy: A Propensity Score-weighted Analysis After Central Pathology Review

BackgroundThe current pathological tumour-node-metastasis (pTNM) classification for upper tract urothelial carcinoma (UTUC) does not include any risk stratification of pT3 renal pelvicalyceal tumours. ObjectiveTo assess the prognostic impact of pT3 subclassification in a multicentre cohort of patients with UTUC of the renal pelvicalyceal system undergoing radical nephroureterectomy (RNU). Design, setting, and participantsData from all consecutive patients treated with RNU for pT3 renal pelvicalyceal UTUC at 14 French centres from 1995 to 2013 were reviewed retrospectively. InterventionA central pathology review (CPR) was used to stratify pT3 patients into those with infiltration of the renal parenchyma on a microscopic level (pT3a) versus those with infiltration of the renal parenchyma visible on gross inspection of the resection specimen and/or invasion of peripelvic fat (pT3b). Outcome measurements and statistical analysisInverse probability weighting (IPW)-adjusted Cox regression analyses were used to compare recurrence-free survival (RFS) and cancer-specific survival (CSS) between pT3a and pT3b patients. Results and limitationsOverall, 202 patients were included and further stratified into pT3a (n = 98; 48.5%) and pT3b (n = 104; 51.5%) subgroups. Median time to follow-up in the weighted population was 68 (interquartile range, 50–95) mo. In IPW-adjusted Cox regression analyses, pT3b versus pT3a substage was associated with a significant adverse effect on RFS (hazard ratio [HR] = 2.02; 95% confidence interval [CI] = [1.36–3.01]; p < 0.001) and CSS (HR = 1.84; 95% CI = [1.20–2.82]; p = 0.005). The study is limited by its retrospective design. ConclusionsUsing IPW-adjusted analyses after the CPR, we observed that RNU patients with pT3b renal pelvicalyceal UTUC had adverse prognosis as compared with those with pT3a disease. As such, this subclassification could help refine the current pTNM system for UTUC. Patient summaryIn this report, we looked at the prognostic interest of stratifying patients with pT3 renal pelvicalyceal upper tract urothelial carcinoma based on the extent of local invasion. We found that those with extensive infiltration (pT3b) had adverse prognosis as compared with those with limited infiltration (pT3a). This information could be provided on pathology reports to further guide clinical decision making.

Primary Report of Totally Tubeless Percutaneous Nephrolithotomy Despite Pelvi-calyceal Perforations.

Nephrostomy tube insertion and/or a ureteral stent placement is advised when pelvi-calyceal perforations are encountered during percutaneous nephrolithotomy (PNL) nevertheless totally tubeless PNL is a possible exit strategy in percutaneous renal surgery therefore case series on the short term clinical outcomes of noninvasive management of iatrogenic pelvicalyceal perforations encountered during PNL is presented. During retrospective analysis of 1271 PNL procedures, 25 incidents of accidental ureteral catheter/ jj stent dislodgement during first 24 post-operative hours were identified in patient who had pelvi calyceal perforations and had no nephrostomy tube (tubeless). Thirteen patients could not be re-stented nor a nephrostomytube could have been placed for them mainly due to patient refusal or comorbid conditions. The main outcome was rate of successful noninvasive management. Eighteen Patients bearing mucosal tears (grade I trauma) or visible peri-pelvic fat (grade II) successfully recovered without need for ureteral stenting or nephrostomy (72.0%). In seven (28.0%) cases of extension of the perforation into the peri-pelvic fat (grade III), either nephrostomy insertion or JJ stenting was needed for resolution of fever and urinoma. The major limitation was the necessity to exclude patients and manage them in the standard fashion according to clinical guidelines. Iatrogenic perforations of the collecting system are quite diverse in terms of severity that result in different natural histories and not all might need urinary diversion via nephrostomy or ureteral stenting.Low grade perforations may be successfully managed in totally tubeless fashion nevertheless further prospective investigations seem warranted.

Kidneys: The Victim Of Hypertension: Review

Background & objectives: Our review discuss the relation between hypertension and the renal system ,and show the cyclic effect of both hypertension and chronic kidney damage on each other, our objectives are to control the high blood pressure with minimal renal affection due to side effects of medications. Materials & methods: many studies and trials compare between different antihypertensive drugs and their effects on kidneys which may decrease their efficiency. Results: Angiotensin converting enzyme inhibitor (ACE-Is), angiotensin II receptor blocker (ARBs), Beta-blockers and calcium channel blockers are identified to be the second line of treatment of hypertension according to a network meta-analysis conducted in 2003, ACE-Is were found to show a significant effect in slowing the progression of nephrosclerosis and slower declining of GFR more than β-blocker or calcium channel blocker. Conclusion: Kidney is indispensable organ in the body that we must protect it from the irreversible macroscopic and microscopic changes pathological as : macroscopic (small size, finely granular surface, adherent and difficulty stripped capsule, fibrotic, atrophic, not demarcated cortex on cut section, thick prominent arterioles and increased peripelvic fat) and microscopic (afferent and efferent arterioles show benign arteriosclerosis, gradual ischemic atrophy and fibrosis of the glomeruli, atrophy of non-functioning tubules related to atrophic glomeruli, may undergo compensatory cystic dilatation of tubule related to functioning glomeruli). ACE-Is is considered the drug of choice in hypertensive patients complicated with chronic kidney disease, In hypertensive patients that are refractory to medical treatment, renal sympathetic denervation is a safe alternative.

AB0993 Indirect Assessment of Amyloid A Deposits in Different Structures of the Kidneys – A Postmortem Clinicopathologic Study of 161 Rheumatoid Arthritis Patients

BackgroundAmyloidosis is a progressive, cumulative process, involving in its early stage only a few structures in some organs, and increasingly more in the later stages of the disease [1].ObjectivesThe aim...

Reassessment of Prognostic Heterogeneity of pT3 Renal Pelvic Urothelial Carcinoma: Analysis in Terms of Proposed pT3 Subclassification Systems

We determined whether the 3 pT3 subclassification systems reported by the Asan, Cornell and Nagoya groups provide an accurate estimation of patient prognosis. We also determined which subclassification is most predictive of the heterogeneous oncological outcomes of pT3 renal pelvic urothelial carcinoma. Using a Korea-Japan multi-institutional, retrospective database 250 pT3 renal pelvic urothelial carcinomas treated with radical nephroureterectomy were assigned to the 3 pT3 subcategories by tumor location and depth of parenchymal invasion after pathological reevaluation. Recurrence-free and cancer specific survival was assessed according to the 3 pT3 subclassifications. Predictive accuracy for survival in 4 models (baseline and each of the 3 pT3 subclassifications) was quantified and predictive accuracy increments for each model were compared. In the baseline multivariate Cox regression model nodal metastasis and high grade were significant for survival. On multivariate analysis including the pT3 subclassifications the 3 subclassifications remained significantly associated with survival rates. Of the 3 pT3 subclassification systems the Cornell subclassification had the highest predictive accuracy for discriminating the heterogeneous prognosis of pT3 renal pelvic urothelial carcinoma, followed by the Nagoya subclassification. Compared with the baseline model adding the Cornell subclassification significantly increased predictive accuracy for recurrence-free survival from 0.687 to 0.742 (p = 0.029) and for cancer specific survival from 0.713 to 0.758 (p = 0.047). The criteria of microscopic vs macroscopic parenchymal invasion and/or peripelvic fat invasion provide the most accurate differential classification of the prognostic heterogeneity of pT3 renal pelvic urothelial carcinoma. Further studies should be performed to determine the need to modify the current pT3 renal pelvic urothelial carcinoma staging system.

Impact pronostique de l’envahissement du parenchyme rénal dans la population des tumeurs de la voie excrétrice urinaire supérieure de stade pT3

Upper tract urinary carcinoma (UTUC) pT3 tumors are a heterogeneous entity including tumors invading the renal parenchyma, tumors with peripelvic fat invasion or peri-ureteral fat invasion. The aim of this study was to evaluate the prognostic significance of these three different groups of pT3 tumors. Between 1998 and 2012, 205 patients with UTUC were operated in two centers, including 52 patients with pT3 tumor stage. pT3 tumors were divided into three groups: peri-ureteral fat invasion (pT3U, n = 16), peripelvic fat invasion (pT3G, n = 21), and renal parenchyma invasion (pT3P, n = 15). The prognostic significance of the type of tumor infiltration was evaluated on specific and disease-free survival. Median follow-up was 18.9 months [6-133.4]. In univariate analysis, renal parenchyma invasion was associated with a better prognostic in both specific (P = 0.026) and disease-free survival (P = 0.031) compared with peripelvic or peri-ureteral fat invasion. Mutivariate analysis retained the pT3 subgroup as an independant prognostic factor in both specific and disease-free survival (P = 0.02). pT3 tumors with renal parenchyma invasion had a better prognosis than those with peripelvic or peri-ureteral fat invasion. The heterogeneity of the pT3 group should be taken into account to improve the care of patients.

Peripelvic/periureteral fat invasion is independently associated with worse prognosis in pT3 upper tract urothelial carcinoma

To elucidate the reasons for conflicting results regarding the prognostic significance of tumor location in upper tract urothelial carcinoma (UTUC), we analyzed the stage-specific impact of tumor location on oncological outcomes following radical nephroureterectomy (RNU). Data from 392 patients who underwent RNU with curative intent between 1991 and 2010 were reviewed. Prognostic impact of tumor location and various clinicopathological factors for recurrence-free survival (RFS) and cancer-specific survival (CSS) was evaluated using Kaplan-Meier and Cox regression analyses at each pathological stage. Tumor location was classified as renal pelvis or ureter, and pT3 tumors were further stratified as invading the renal parenchyma or peripelvic or periureteral fat. In stage-specific analysis, tumor location did not have prognostic significance in patients with ≤pT2 tumors, whereas RFS and CSS rates were significantly lower in patients with pT3 ureteral tumors than renal pelvic tumors. Subgroup analysis showed that RFS and CSS rates were significantly higher for pT3 tumors invading the renal parenchyma than the peripelvic or periureteral fat. On multivariate analysis in pT3 tumors adjusting other clinicopathological parameters, tumor location remained significant predictors for both RFS and CSS. Compared with tumors invading renal parenchyma, tumors invading peripelvic fat or periureteral fat were associated with about 3.5 times higher risk for cancer-specific mortality (p < 0.05). Location-dependent survival difference exists only in patients with pT3 UTUC. Conflicting institutional results regarding tumor location in UTUC may be due to difference in the proportions of parenchymal versus peripelvic fat invasion in pT3 pelvic tumors.

Clear Cell Adenocarcinoma of the Renal Pelvis in a Male Patient

Carcinoma of the renal pelvis is an uncommon renal neoplasm. Clear cell adenocarcinoma in the urinary tract is rare and has a histomorphology resembling that of the female genital tract. We herein present a case of clear cell adenocarcinoma of the renal pelvis, which is the first example in a male patient to our knowledge. A 54-year-old man presented with right flank pain. The tumor was associated with renal stones and hydronephrosis and invaded into the peripelvic fat tissue with regional lymph node metastasis. The patient died of metastatic disease six months postoperatively. Histologically, the tumor showed complex papillary architecture lined with clear and hobnail cells. Clear cell adenocarcinoma of the renal pelvis may pose a diagnostic challenge on histological grounds, particularly in the distinction from renal cell carcinoma. The immunohistochemical stains could help confirm the diagnosis. Due to its rarity, an effective treatment regimen remains to be determined.

Is pT3 urothelial carcinoma of the renal pelvis a homogeneous disease entity? Proposal for a new subcategory of the pT3 classification

The prognosis of urothelial carcinoma of the renal pelvis (UCRP) is heterogeneous, especially in pT3 patients. The degree of tumour parenchymal invasion is not considered for pathological tumour (pT) staging. The aim of this study was to investigate whether quantitative assessment of invasion provides a better estimation of prognosis for UCRP in pT3 patients. We reclassified pT3 cases into two subcategories: pT3a, in which UCRP extended only into the renal medulla; and pT3b, in which UCRP extended into the renal cortex and/or in which UCRP exhibited peripelvic fat invasion. We examined our proposed pT classification and other pathological parameters, including necrosis, lymph-vascular invasion (LVI), 1973 World Health Organization (WHO) grading, WHO/International Society of Urological Pathology grading, adjuvant chemotherapy, and pathological lymph node metastasis (pN). The study included 275 patients. Among 96 patients with pT3, there was a statistically significant difference between the pT3a and pT3b subcategories in cancer-specific survival (P < 0.001). Our proposed pT classification, as well as necrosis, LVI, 1973 WHO grading, and pN, demonstrated prognostic differences in univariate analysis, whereas in multivariate analysis, only our proposed classification (P = 0.008) and pN (P = 0.002) were statistically significant. The pT3b subcategories should be regarded as true pT3, having the established features of that stage, whereas pT3a has a better prognosis.

The Protective Role of Renal Parenchyma as a Barrier to Local Tumor Spread of Upper Tract Transitional Cell Carcinoma and its Impact on Patient Survival

We investigated whether tumor location has independent prognostic significance in upper tract transitional cell carcinoma cases and which factor determines it. We reviewed data on 122 renal pelvis and 102 ureteral tumor cases, including the recurrence pattern. Tumor location and other clinicopathological variables were evaluated regarding cancer specific and recurrence-free survival. Stage pT3 tumors were stratified into those invading renal parenchyma or peripelvic/periureteral fat. Overall 5-year cancer specific survival and recurrence-free survival rates were 77.0% and 71.6%, respectively, at a mean followup of 60.7 months. Of the clinicopathological parameters T stage was the most significant prognosticator of the survival rate, while nodal involvement, high grade and ureteral tumor location were also significant for lower survival rates. Stratification analysis for matching pathological stage revealed that, while survival rates were similar in the renal pelvis and ureteral tumor groups at stage pT2 or less, renal pelvic tumors were associated with significantly higher survival rates than ureteral tumors for stage pT3. Specifically renal pelvic tumors invading the renal parenchyma were associated with a lower local failure rate, and higher cancer specific and recurrence-free survival rates than tumors invading peripelvic or periureteral fat, ie 77.5% vs 49.7% 5-year cancer specific survival and 75.6% vs 32.0% 5-year recurrence-free survival (p = 0.014 and 0.003, respectively). Tumor location is an independent prognostic factor for pT3 upper tract transitional cell carcinoma. The overall better prognosis of renal pelvic tumors was mainly attributable to pT3 tumor outcomes, specifically lesions invading the renal parenchyma. These findings may be due to the protective role of thick renal parenchyma against local tumor spread.

Prognostic Impact of Peripelvic Fat Invasion in pT3 Renal Pelvic Transitional Cell Carcinoma

Renal pelvic transitional cell carcinoma (TCC), which invades beyond muscularis into peripelvic fat or the renal parenchyma, is diagnosed as stage pT3 despite its structural complexity. We evaluated the prognostic impact of peripelvic fat invasion in pT3 renal pelvic TCC. Between 1986 and 2004, the medical records on 128 patients who were surgically treated for renal pelvic TCC were retrospectively reviewed. Sixty patients with pT3 disease were eligible for the main analysis. The prognostic impact of various clinicopathological factors was analyzed using univariate and multivariate analyses. On univariate analysis, sex, age, concomitant bladder tumors, concomitant ureter tumors, lymphadenectomy, adjuvant chemotherapy, tumor grade, multiplicity, renal parenchymal invasion, and carcinoma in situ did not influence the disease-specific survival (p>0.05). By contrast, peripelvic fat invasion, lymph node invasion, and lymphovascular invasion were each significantly associated with disease-specific survival (p<0.05). Multivariate analysis showed that peripelvic fat invasion (p=0.012) and lymph node invasion (p=0.004) were independent prognostic factors. In conclusion, peripelvic fat invasion is a strong prognostic factor in pT3 renal pelvic TCC. Thus, systemic adjuvant therapy should be considered in the presence of peripelvic fat invasion, even if the lymph nodes are not involved.

A proposal for a novel staging system in renal pelvicaliceal urothelial carcinomas

Renal caliceal urothelial carcinomas, which have characteristic microanatomies in which the tumor directly interfaces to the renal parenchyma without intervening muscle propria, are often overstaged using the existing staging system. Relying on our analysis of 150 renal caliceal and/or pelvic urothelial carcinomas, we propose a novel staging scheme based on the extent of invasion relative to the corticomedullary junction (CMJ). Tumors were classified as category pT2 when renal parenchymal invasion was present within the CMJ and where the renal papillae and medulla were dominant. Tumors going over the CMJ were classified as pT3 with the proposed new scheme. It is very important to exclude pagetoid spread along the collecting ducts/ducts of Bellini to evaluate true invasion into the renal parenchyma. Using this revised staging scheme, 38.5% of tumors that were previously classified as pT3 were reclassified into the pT2 or pT1 groups. On multivariate Cox proportional hazard regression analysis, the extent of CMJ invasion and peripelvic fat invasion were the most significant prognostic indicators (P < .001, HR, 9.308; P = .016, HR, 2.538, respectively). In the new scheme, pT3 tumors showed a tendency to be classified toward the pT4 stage, whereas pT2 tumors were classified closer to the pT1 stage than to the pT3 (pT3 vs pT4, P = .0127; pT3 vs pT2, P < .0001). Renal parenchymal invasion beyond the CMJ has a strong prognostic impact for renal caliceal carcinomas. Using this new staging scheme, we can more precisely evaluate the level of tumor invasion.

UP-03.94: Subdivision of Stage pT3 in urothelial carcinoma of the renal pelvis facilitates detection of patients at high risk for failure

Stage pT3 in urothelial carcinoma (UC) of the renal pelvis comprises tumours invading beyond muscularis into peripelvic fat or renal parenchyma. Our study aimed to assess the potential value of a subdivision of stage pT3 in predicting patient outcome.

Lesions produced by the extravasation of urine from the upper urinary tract.

We present six cases which illustrate the spectrum of clinical features, macroscopic findings and light microscopic findings of urine extravasation from the upper urinary tract. The early lesions are characterized macroscopically by an oedematous, glistening or gelatinous appearance to the renal perihilar and peripelvic fat. Light microscopically there is lipolysis with associated foamy macrophages, multinucleate giant cells and lymphocytes. Immunohistochemical staining for Tamm-Horsfall protein is strongly positive in the extracellular space and in the foamy macrophages confirming urine extravazation. Later lesions are characterized by cicatrization of fibrous tissue around the renal pelvis and hydronephrosis. Microscopically there is relatively bland fibrosis with occasional lymphocytes and histiocytic cells. The late lesions are also characterized by extracellular deposits of weakly eosinophilic, granular or hyaline material, the so called 'urinary precipitates'. These deposits stain strongly with diastase PAS and weakly positive for Tamm-Horsfall protein. The staining of these urinary precipitates is analogous to renal tubular hyaline casts, thus supporting the theory that they are derived from uroproteins. We consider that these deposits are pathognomic of past urine extravasation.

BILATERAL PERIPELVIC FAT SIMULATING RENAL PELVIC TUMOR

Lipomas are benign tumors which may simulate peripelvic masses and usually originate in the renal cortex or the perirenal adipose tissue. Excessive proliferation of the peripelvic fat of the kidney simulating a renal pelvic tumor was detected in our case, illustrating a rare instance in which the kidney was salvaged.

CT of Carcinoma of the Renal Pelvis

CT in 28 histologically proven carcinomas of the renal pelvis (pTa-2, n = 12; pT3-4, n = 16) in 26 patients was evaluated retrospectively. Twenty-four of 28 tumors could be identified at CT, 17/28 at urography, and 12/14 at retrograde pyelography. Nineteen tumors appeared as a discrete intrapelvic mass with an attenuation close to that of the kidney on noncontrast scans. There was slight to moderate enhancement of the tumors following i.v. contrast medium injection but they appeared hypodense relative to the renal parenchyma. Five tumors caused only a diffuse obliteration of the renal sinus. Criteria to define peripelvic tumor growth are proposed, i.e. tumors obliterating fat planes or abutting of renal parenchyma should not be regarded as signs of extrapelvic extension, while inhomogeneous attenuation of peripelvic fat and renal parenchyma (in the absence of other explanation) should, or if the tumor mass is seen interdigitizing with surrounding structures. Thickening of Gerota's fascia or septa in the perirenal space are unspecific findings. With CT we were able to differentiate tumors confined to the renal pelvic wall from those with more advanced disease including metastases in 22 of 26 patients.

Echo-free and relatively echo-free "renal sinus lipomatosis".

Eleven echo-free and 37 relatively echo-free peripelvic lesions, primarily interpreted as sinus lipomatosis by experienced sonologists, were examined using CT. Eight echo-free lesions proved to be cysts and only three "fibrous fat". Hypodense peripelvic fat accumulations were not totally echo-free in any of the cases, but tended to show up weak echos.

Excessive proliferation of peripelvic fat of the kidney

Excessive proliferation of the peripelvic fat of the kidney (EPPF) is a benign process with an innocuous effect on the patient. However, this condition may assume major clinical significance by producing pyelocalyceal deformities that may be mistaken for true renal masses. Rarely, EPPF may masquerade as a renal pelvic tumor. We present the second reported case of EPPF simulating a renal pelvic tumor and review the history as well as the characteristic radiographic and sonographic features of this condition.