Peritumoral Pseudocapsule Research Articles

Characteristics of peritumoral pseudocapsule in small renal cell carcinoma and its influencing factors.

The aim of this study was to investigate the peritumoral pseudocapsule (PC) status and identify the factors influencing PC status in small renal cell carcinoma (RCCs). A total of 147 patients with small RCC (≤4cm) who had undergone tumor enucleation (TE) were assigned into three groups according to PC status: complete PC, PC absence, and PC invasion. Computed tomography (CT) imaging and clinicopathological features were compared among the three groups. Univariate and multivariate analyses were performed to identify factors associated with incomplete PC. The number of patients with complete PC, PC absence, and PC invasion was 87 (59%), 20 (14%), and 40 (27%), respectively. Compared with the other two groups, tumors with complete PC were most common in clear cell RCC (CCRCC) and showed a hyperenhancement pattern (92%) and clear boundary (63%) on CT scanning images (p < 0.001). PC absence was most common in female patients (50%), whereas PC invasion was more common in male patients (85%) (p=0.017). The tumor diameter in the PC absence group (2.24 ± 0.93 cm) was shorter compared with that of the complete PC group (2.88 ± 0.76 cm) and PC invasion group (3.16 ± 0.64 cm) (p < 0.001). Univariate and multivariate analysis showed that hypoenhancement pattern, unclear boundary, and non-CCRCC subtype were independent risk factors of incomplete PC. Hypoenhancement pattern, unclear boundary, and non-CCRCC subtype were significant predictors of incomplete PC in small RCCs. It remains to be established whether TE is an appropriate procedure for patients with incomplete PC.

Histopathological validation of safe margin for nephron-sparing surgery based on individual tumor growth pattern

BackgroundTo evaluate the clinicopathologic value of morphological growth patterns of small renal cell carcinoma (sRCC) and determine the actual demand for taking a rim of healthy parenchyma to avoid positive SM.MethodsData was collected from 560 sRCC patients who underwent laparoscopic surgeries from May 2010 to October 2017. One hundred forty-nine cases received nephron-sparing surgery (NSS) and others received radical nephrectomy (RN). All specimens were analyzed separately by two uropathologists, and three morphological growth patterns were identified. The presence of pseudocapsule (PC), surgical margins (SM), and other routine variables were recorded. The relationship between growth patterns and included variables was measured by the χ2 test and Fisher’s exact probability test. Survival outcomes were evaluated by Kaplan-Meier method and the log-rank test.ResultsThe median age of patients was 63.2 years old and the mean tumor diameter was 3.0 cm. Four hundred eighty (85.7%) cases were clear cell RCC and 541 (96.6%) cases were at the pT1a stage. Peritumoral PC was detected in 512 (92.5%) specimens, and the ratio of tumor invasion in PC in infiltration pattern increased obviously than that of the other growth patterns. Similarly, the pT stage was significantly correlated with the infiltration pattern as well. One hundred forty-nine patients underwent NSS and 3 (2.0%) of them showed positive SM after operation. Statistical differences of the 5-year overall survival (OS) and the cancer-specific survival (CSS) existed between different morphological growth patterns, PC status, and pT stages.ConclusionsMorphological growth patterns of sRCC might be used as a potential biomarker to help operate NSS to avoid the risk of positive SM. How to distinguish different morphological growth patterns before operation and the effectiveness of the growth pattern as a novel proposed parameter to direct NSS in sRCC patients deserves further exploration.

Early dark cortical band sign on CT for differentiating clear cell renal cell carcinoma from fat poor angiomyolipoma and detecting peritumoral pseudocapsule.

To retrospectively evaluate whether the early dark cortical band (EDCB) on CT can be a predictor to differentiate clear cell renal cell carcinoma (ccRCC) from fat poor angiomyolipoma (Fp-AML) and to detect peritumoral pseudocapsules in ccRCC. The EDCBs, which are comprised of unenhanced thin lines at the tumor-renal cortex border in the corticomedullary phase, on the CT images of 342 patients who underwent partial nephrectomy were evaluated. Independent predictors among the clinical and CT findings for differentiating ccRCC from Fp-AML were identified using multivariate analyses. The diagnostic performance of the EDCB for diagnosing peritumoral pseudocapsule in ccRCC and differentiating ccRCC from Fp-AML was calculated. The EDCB was observed in 157 of 254 (61.8%) ccRCCs, 4 of 31 (12.9%) chromophobe RCCs, 1 of 21 (4.8%) papillary RCCs, 3 of 11 (27.3%) clear cell papillary RCCs, 3 of 8 (37.5%) oncocytomas, and 0 of 17 (0%) Fp-AMLs. There was substantial interobserver agreement for the EDCB (k = 0.719). The EDCB was a significant predictor for differentiating ccRCC from Fp-AML (p < 0.001). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value of the EDCB for differentiating ccRCC from Fp-AML were 61.8%, 100%, 100%, and 14.9%, respectively, and those for detecting pseudocapsule in 236 ccRCCs were 62.3%, 68.8%, 96.5%, and 11.7%, respectively. Although diagnostic accuracy of the EDCB for detecting peritumoral pseudocapsule in RCC is inadequate, it can be a predictor for differentiating ccRCC from Fp-AML with high specificity and PPV. • The early dark cortical band (EDCB) sign is observed in nearly two-thirds of clear cell renal cell carcinoma (ccRCC) that are treated by partial nephrectomy and have substantial interobserver agreement. • The EDCB is a significant predictor for differentiating ccRCCs from fat poor angiomyolipomas, with a high specificity and positive predictive value. • Diagnostic accuracy of the EDCB for detecting peritumoral pseudocapsule in ccRCC is inadequate, though better than those in the nephrographic and excretory-phase images.

Detection of a peritumoral pseudocapsule in patients with renal cell carcinoma undergoing robot-assisted partial nephrectomy using enhanced MDCT

To investigate the detection of peritumoral pseudocapsule (PC) using multi-detector row computed tomography (MDCT) for tumors resected by robot-assisted laparoscopic partial nephrectomy (RAPN) for T1 renal cell carcinoma (RCC). Study participants included 206 patients with clinical T1 RCC who underwent RAPN between October 2017 and February 2018. Two radiologists who were blinded to the pathological findings evaluated the computed tomography (CT) images. Radiological diagnosis of a PC was defined by a combination of observations, including a low-attenuation rim between the tumor and renal cortex in the cortico-medullary phase and a high-attenuation rim at the edge of the tumor in the nephrogenic or excretory phase. A PC was detected on CT in 156/206 tumors (76%) and identified by pathology in 182/206 (88%) tumors including 153/166 (92%) clear cell RCC, 13/14 (93%) papillary RCC, and 7/16 (44%) chromophobe RCC. In the whole cohort, CT findings showed a sensitivity of 81.3% (148/182), specificity of 66.7% (16/24), and positive predictive value of 94.9% (148/156). When the data were stratified according to pathological subtypes, MDCT was observed to have a sensitivity of 86.9% (133/153) and specificity of 61.5% (8/13) in clear cell RCC, sensitivity of 38.5% (5/13) and specificity of 100% (1/1) in papillary RCC, and sensitivity of 44.4% (4/7) and specificity of 66.7% (6/9) in chromophobe RCC. A low or high-attenuation rim around the tumor in the cortico-medullary or nephrographic-to-excretory phase indicates a PC of RCC, though the accuracy is not satisfactory even with 64- or 320-detector MDCT.

The Optimal Surgical Margins of Nephron-sparing Surgery for Stage T 1b Renal Tumors

To analyze the pathological characteristics and explore the optimal surgical margins (SM) of nephron-sparing surgery (NSS) for stage T 1b renal carcinoma (4-7 cm) on preoperative imaging. The clinical and pathological data of 245 cases of stage T 1b kidney cancer from September 2013 to December 2017 were collected and reviewed retrospectively. The radical nephrectomy (RN) was performed on 174 cases and other 71 cases accepted NSS. There were 158 males and 87 females, with a mean age of 59.6 years and mean tumor size of 5.3 cm. Through postoperative pathological examination, 209 (85.3%) cases were confirmed renal clear cell carcinoma and 219 (89.4%) cases were surrounded with visible peritumoralpseudocapsule (PC). 26 (10.6%) cases of cancerous cells invaded beyond peritumoral PC and into renal parenchyma. The infiltrative depth into renal parenchyma beyond PC was all limited in 3 mm and the cases of ≤1, 1-2 and 2-3 mm were 7 (26.9%), 16 (61.5%) and 3 (11.5%), respectively. Multifocal tumors were discovered in 24 (9.8%) cases. The average resection margin for partial nephrectomy was 5 mm (3-7 mm). For stage T 1b renal tumors, NSS is acceptable and a 3 mm of surgical margin is safe and suitable to avoid positive SM.

479 - Detection of a peritumoral pseudocapsule in patients with renal cell carcinoma undergoing robot-assisted partial nephrectomy, using enhanced CT

479 - Detection of a peritumoral pseudocapsule in patients with renal cell carcinoma undergoing robot-assisted partial nephrectomy, using enhanced CT

A preoperative nomogram predicting the pseudocapsule status in localized renal cell carcinoma.

BackgroundTumor enucleation (TE) surgery for localized renal cell carcinoma (RCC) relies on a complete peritumoral pseudocapsule (PC). Study objective was to develop a preoperative model to predict PC status.MethodsThe prediction model was developed in a cohort that consisted of 170 patients with localized RCC, and data was gathered from 2010 to 2015. Multivariable logistic regression analysis and R were used to generate this prediction model. The statistical performance was assessed with respect to the calibration, discrimination, and clinical usefulness.ResultsThe prediction model incorporated the systemic inflammatory markers [neutrophil-lymphocyte ratio (NLR); albumin-globulin ratio (AGR)], CT imaging features (tumor size and necrosis), and clinical risk factors (BMI). The model showed good discrimination, with a C-index of 0.85 (0.78–0.91), and good calibration (P=0.60). The sensitivity and specificity were 62% and 94% respectively. Decision curves and clinical impact curve demonstrated that the current model was clinically useful.ConclusionsWe constructed a model that incorporated both the systematic inflammatory markers and clinical risk factors. It can be conveniently used to preoperatively predict the individualized risk of PC invasion and identify the best candidates to receive TE surgery.

SC11 - Five-years outcomes following holmium laser enucleation of the prostate in 180 consecutive patients in a single center serie evaluation of peritumoral pseudocapsule characteristics: preliminary results

SC11 - Five-years outcomes following holmium laser enucleation of the prostate in 180 consecutive patients in a single center serie evaluation of peritumoral pseudocapsule characteristics: preliminary results

SC2 - Evaluation of peritumoral pseudocapsule characteristics: Preliminary results

SC2 - Evaluation of peritumoral pseudocapsule characteristics: Preliminary results

IJU this issue

IJU this issue

MP19-20 DETECTION OF A PERITUMORAL PSEUDOCAPSULE IN PATIENTS WITH RENAL CELL CARCINOMA UNDERGOING ROBOT-ASSISTED PARTIAL NEPHRECTOMY, USING ENHANCED CT

INTRODUCTION AND OBJECTIVES:Tumor enucleation with partial nephrectomy for treatment of renal tumors yields a specimen that includes a tumor surrounded by the peritumoral pseudocapsule (PC) with mi...

Editorial Comment to Peritumoral pseudocapsule status according to pathological characteristics from robot‐assisted laparoscopic partial nephrectomy for localized renal cell carcinoma

Editorial Comment to Peritumoral pseudocapsule status according to pathological characteristics from robot‐assisted laparoscopic partial nephrectomy for localized renal cell carcinoma

Peritumoral pseudocapsule status according to pathological characteristics from robot-assisted laparoscopic partial nephrectomy for localized renal cell carcinoma.

To investigate peritumoral pseudocapsule status in patients with renal cell carcinoma who underwent robot-assisted laparoscopic partial nephrectomy, and to examine predictive factors associated with the absence of peritumoral pseudocapsule. A total of 367 patients with clinical T1 renal cell carcinoma who underwent robot-assisted laparoscopic partial nephrectomy were divided into two groups according to peritumoral pseudocapsule status. The groups were compared in terms of patient and tumor characteristics. Multivariate logistic regression analysis was carried out to identify predictive factors for the absence of peritumoral pseudocapsule. Of the 367 tumors, 323 (88%) were surrounded by a peritumoral pseudocapsule. The mean tumor size was 30mm, and 70% of the patients were male. Tumors with a peritumoral pseudocapsule had a larger diameter than those without (31 vs 26mm; P=0.0008). A peritumoral pseudocapsule was observed in 92% of the clear cell, in 89% of the papillary and in 86% of the clear cell papillary renal cell carcinoma cases compared with just 50% in the chromophobe renal cell carcinoma cases (P<0.0001). Sex, age, Fuhrman grade and tumor complexity did not differ among patients. A multivariate analysis showed that smaller tumor size (≥34 vs <34mm, odds ratio 3.31; P=0.0023) and chromophobe renal cell carcinoma (vs other subtypes, odds ratio 12.5; P<0.0001) predicted an absence of peritumoral pseudocapsule. Small tumor size and chromophobe renal cell carcinoma were significant predictors of a lack of peritumoral pseudocapsule, suggesting that a positive surgical margin must be avoided for these tumors when an enucleation technique is used for robot-assisted laparoscopic partial nephrectomy.

Tumor–parenchyma interface and long-term oncologic outcomes after robotic tumor enucleation for sporadic renal cell carcinoma

ObjectiveTumor enucleation has been shown to be oncologically safe for elective treatment of renal cell carcinoma (RCC); yet, evidence on long-term oncologic outcomes after robotic tumor enucleation is lacking.In this study we provide a detailed histopathological analysis of tumor–parenchyma interface and the long-term oncologic outcomes after robotic tumor enucleation for sporadic RCC in a high-volume referral center. Materials and MethodsWe selected consecutive patients undergoing robotic tumor enucleation for sporadic RCC by experienced surgeons with at least 4 years of follow-up.Pattern of pseudocapsule (PC) invasion, thickness of healthy renal margin removed with the tumor, margin status and recurrence rate were the main study endpoints. Multivariable models evaluated independent predictors of PC invasion. ResultsOverall, 140 patients were eligible for the study. Of these, 127 (91%) had complete data available for analysis. Median thickness of healthy renal margin was 0.57 mm (interquartile range [IQR] 0.24–103).A distinct peritumoral PC was present in 121/127 (95%) tumors with a median thickness of 0.28 mm (IQR 0.14–0.45).In 24/121 (19.8%) cases, RCC showed complete PC invasion. At multivariable analysis, increasing tumor diameter, endophytic rate > 50% and papillary histology were significantly associated with complete PC invasion.Positive surgical margins were reported in 3/127 (2.4%) cases. At a median follow-up of 61 months (range 48–76), one patient died due to metastatic RCC. Among patients alive at follow-up, no cases of recurrence at the enucleation site were recorded, while three cases (2.4%) of renal recurrence (elsewhere in the ipsilateral kidney) and three cases (2.4%) of systemic recurrence were found. ConclusionsDistinct RCC-related features were associated with complete PC invasion. By providing a microscopic layer of healthy renal margin in almost all cases, robotic tumor enucleation achieved negative surgical margins in the vast majority of patients, even in case of complete PC invasion. At long-term follow-up, no recurrences were found at the enucleation site. Although our findings need to be confirmed by larger studies with longer follow-up, robotic tumor enucleation appears oncologically safe in experienced hands for the treatment of sporadic RCC.

Histopathologic analysis of stage pT1b kidney neoplasms for optimal surgical margins of nephron-sparing surgery

ObjectiveTo evaluate the pathological features and define the optimal surgical margins (SM) of nephron-sparing surgery (NSS) for kidney neoplasms 4–7 cm (stage pT1b) on preoperative imaging.Materials and methodsThe retrospective study included 748 patients who were diagnosed stage pT1b renal tumors and underwent either radical nephrectomy (RN, n = 475) or NSS (n = 273) from January 2004 to March 2017. The tumor size, pathological subtype, Fuhrman grade, status of peritumoral pseudocapsule (PC) and tumor multifocality were recorded. The relationship between peritumoral PC and positive SM was calculated statistically by Fisher’s exact probability test.ResultsThe mean tumor diameter was 5.4 cm (range: 4.1–7.0 cm), 65 (8.7%) cases were discovered with multifocal lesions and 686 (91.7%) were surrounded with peritumoral PC in all 748 specimens. 57 (8.3%) of 686 cases were proved with tumor infiltrated beyond PC [infiltration (+)], and the presence of PC infiltration (+) was significantly correlated with positive SM (p = 0.016). The infiltrative depth of tumor cells into renal parenchyma beyond PC was all limited in 3 mm and the proportion of ≤ 1, 1–2 and 2–3 mm was 21.1% (12/57), 59.6% (34/57) and 19.3% (11/57), respectively.ConclusionsOur report indicates a 3 mm excisional margin is acceptable to ensure negative SM when operating NSS on stage pT1b kidney neoplasms.

Prognostic significance of poorly differentiated clusters and tumor budding in colorectal liver metastases.

Histomorphological features have been described as prognostic factors after resection of colorectal liver metastases (CLM). The objectives of this study were to assess the prognostic significance of tumor budding (TB) and poorly differentiated clusters (PDC) among CLM, and their association with other prognostic factors. We evaluated 229 patients who underwent a first resection of CLM. Slides stained by HE were assessed for TB, PDC, tumor border pattern, peritumoral pseudocapsule, peritumoral, and intratumoral inflammatory infiltrate. Lymphatic and portal invasion were evaluated through D2-40 and CD34 antibody. Factors independently associated with poor overall survival were nodules>4 (P = 0.002), presence of PDC G3 (P = 0.007), portal invasion (P = 0.005), and absence of tumor pseudocapsule (P = 0.006). Factors independently associated with disease-free survival included number of nodules>4 (P < 0.001), presence of PDC G3 (P = 0.005), infiltrative border (P = 0.031), portal invasion (P = 0.006), and absent/mild peritumoral inflammatory infiltrate (P = 0.002). PDC and TB were also associated with histological factors, as portal invasion (TB), peritumoral inflammatory infiltration (PDC), infiltrative border, and absence of tumor pseudocapsule (TB and PDC). This is the first study demonstrating PDC as a prognostic factor in CLM. TB was also a prognostic factor, but it was not an independent predictor of survival.

Histopathologic analysis of tumor bed and peritumoral pseudocapsule after in vitro tumor enucleation on radical nephrectomy specimen for clinical T1b renal cell carcinoma

PurposeThis study was designed to assess the feasibility and histopathologic safety of tumor enucleation for renal cell carcinoma, through histopathologic analysis of the tumor bed and peritumoral pseudocapsule (PC) after in vitro tumor enucleation. Materials and methodsWe studied 176 radical nephrectomy specimens for clinical T1b renal cell carcinoma in our institution, from January 2013-February 2016. Immediately after the kidney was excised, the tumor of radical specimen was enucleated in vitro. The tumor bed parenchyma of 15mm beyond the PC was examined to investigate the possible presence of tumor invasion or satellite lesions. The PC invasion was also evaluated. ResultsThe average tumor size was 5.7±0.7cm. The histopathologic evaluation revealed that 68.2% of tumors were clear cell renal cell carcinoma (RCC). The pathological staging showed that 92.6% of tumors were pT1b, 2.8% were pT2, and 4.5% were pT3a. For clinical T1b RCC, tumor infiltration on tumor bed was detected in 6 cases (3.4%), and satellite lesion was detected in 3 (1.7%). In the group of grade 1 to 2, 4 (2.3%) were found with residual tumor, and 5 (2.8%) in the group of grade 3 to 4 (P = 0.133). Papillary RCC had the highest rate of residual tumors (8.8%). A statistically significant association of peritumoral PC invasion with tumor size and pathologic grade was observed. Median follow-up was 23 months (range: 6–43) with a recurrence rate of 6.3% (11 of 176) and a cancer-specific mortality rate of 2.8% (5 of 176). ConclusionsFor clinical T1b renal cell carcinoma, the risks of tumor infiltration or satellite lesions on enucleation tumor bed or both are relatively low. Peritumoral PC invasion is associated with tumor size and pathologic stage. Tumor enucleation is a histopathologically safe technique for patients undergoing partial nephrectomy.

Characteristics of the peritumoral pseudocapsule vary predictably with histologic subtype of T1 renal neoplasms. Jacob JM, Williamson SR, Gondim DD, Leese JA, Terry C, Grignon DJ, Boris RS.Urology. November 2015;86(5):956–961.

ObjectiveTo determine characteristics of the peritumoral pseudocapsule (PC) between renal tumor subtypes. MethodsThe peritumoral PCs of 160 pT1 renal tumors were examined, including 60 clear cell renal cell carcinomas (RCCs), 50 papillary RCCs, 25 chromophobe RCCs, and 25 oncocytoma. Pathologic features (presence or absence of PC, mean thickness, continuity, and invasion by tumor) were analyzed. PC thickness was measured using an ocular micrometer to the nearest 1/10mm. ResultsA complete PC was found in 77% of clear cell tumors, 74% of papillary, 28% of chromophobe, and 4% of oncocytomas. Tumor PC was present but incomplete in 18% of clear cell, 18% of papillary, 44% of chromophobe, and 56% of oncocytoma. The PC was entirely absent in no clear cell tumors, 6% of papillary, 28% of chromophobe, and 40% of oncocytoma. Mean PC thickness and presence of invasion beyond the PC differed significantly by tumor subtype. Clear cell RCC possessed the thickest PC showing invasion through the capsule in 8% of tumors compared to 30% of papillary tumors. Complete PC invasion was not seen in chromophobe RCC or renal oncocytoma. Oncocytoma and chromophobe RCC characteristically exhibited an incomplete or absent PC. ConclusionsThe characteristics of peritumoral PC vary predictably with histologic subtype of renal neoplasms. Clear cell RCC shows the most consistent PC, with a lower rate of invasion beyond it compared to papillary RCC. Chromophobe and oncocytoma characteristically have an incomplete or absent PC.

1046 - Histopathological analysis of peritumoral pseudocapsule infiltration and surgical margin status after enucleative robot-assisted partial nephrectomy (RAPN) for malignant renal tumors

1046 - Histopathological analysis of peritumoral pseudocapsule infiltration and surgical margin status after enucleative robot-assisted partial nephrectomy (RAPN) for malignant renal tumors

Characteristics of the Peritumoral Pseudocapsule Vary Predictably With Histologic Subtype of T1 Renal Neoplasms

To determine characteristics of the peritumoral pseudocapsule (PC) between renal tumor subtypes. The peritumoral PCs of 160 pT1 renal tumors were examined, including 60 clear cell renal cell carcinomas (RCCs), 50 papillary RCCs, 25 chromophobe RCCs, and 25 oncocytoma. Pathologic features (presence or absence of PC, mean thickness, continuity, and invasion by tumor) were analyzed. PC thickness was measured using an ocular micrometer to the nearest 1/10 mm. A complete PC was found in 77% of clear cell tumors, 74% of papillary, 28% of chromophobe, and 4% of oncocytomas. Tumor PC was present but incomplete in 18% of clear cell, 18% of papillary, 44% of chromophobe, and 56% of oncocytoma. The PC was entirely absent in no clear cell tumors, 6% of papillary, 28% of chromophobe, and 40% of oncocytoma. Mean PC thickness and presence of invasion beyond the PC differed significantly by tumor subtype. Clear cell RCC possessed the thickest PC showing invasion through the capsule in 8% of tumors compared to 30% of papillary tumors. Complete PC invasion was not seen in chromophobe RCC or renal oncocytoma. Oncocytoma and chromophobe RCC characteristically exhibited an incomplete or absent PC. The characteristics of peritumoral PC vary predictably with histologic subtype of renal neoplasms. Clear cell RCC shows the most consistent PC, with a lower rate of invasion beyond it compared to papillary RCC. Chromophobe and oncocytoma characteristically have an incomplete or absent PC.