Pathologic analysis of non-neoplastic parenchyma in renal cell carcinoma: a comprehensive observation in radical nephrectomy specimens

Pathological Insights into Non-Neoplastic Renal Parenchyma in Wilms Tumor: Implications for Nephron-Sparing Surgery

INTRODUCTION

 This study aimed to evaluate the non-neoplastic renal parenchyma in Wilms tumor (WT) and investigate its impact on nephron-sparing surgery (NSS).

MATERIALS AND METHODS

 The non-neoplastic renal parenchyma of WT patients was prospectively collected for pathological examination. The histology of non-neoplastic renal parenchyma was assessed from two perspectives: nephrogenic rests (NRs) and nephrons.

RESULTS

 A total of 46 non-neoplastic renal parenchyma specimens were collected from 42 WT patients. The surgeons assessed the median proportion of non-neoplastic renal parenchyma as 30%, whereas using ellipsoid volume, it was calculated to be 27%. The Youden index of surgeons' assessment peaked at a 15% proportion of non-neoplastic renal parenchyma. The bilateral WT (BWT) group and NSS group exhibited significant differences compared with the unilateral WT group and radical nephrectomy group, respectively, with the BWT group showing a tendency toward thickened basement membrane.

CONCLUSION

 The presence of NRs and endogenous nephron alternations should be given due attention in WT. The probability of abnormalities is low when the proportion of non-neoplastic renal parenchyma exceeds 15%, providing pathological support for expanding the adaptation of NSS.

Heavy chain deposition disease in a case of clear cell renal cell carcinoma- A jack in the box

Renal cell carcinoma (RCC) is the most common subtype of adult renal tumors, and its detection rate in the early stages has been increased in the dawn of advanced imaging modalities. Nephrectomy is the mainstay of treatment; determination of tumor category and staging is the primary concern of oncopathologists. Non-neoplastic renal parenchyma is overlooked majority of times and thus misses the opportunity to detect concomitant medical renal diseases which also predict the renal outcome in the postoperative era. Although any kind of glomerular or extraglomerular pathology may be encountered, vascular changes in the form of arterionephrosclerosis are the commonest one. Here, we take the opportunity to report an unusual association of heavy chain deposition disease (HCDD) with clear cell subtypes of renal cell carcinoma in a 48-year-old male of Indian ethnicity.

Characterization of the Peritumoral Atrophic Band and Nonneoplastic Renal Parenchyma in Radical Nephrectomy Specimens

OBJECTIVES

Pathologic evaluation of nonneoplastic renal parenchyma in nephrectomy specimens is important for identifying chronic kidney disease and diabetic nephropathy, but increasing utilization of partial nephrectomies has led to less-sampled nonneoplastic parenchyma. The sampled tissue is often composed predominantly of the peritumoral atrophic band (PAB) directly adjacent to the tumor. We sought to determine the characteristics of the PAB and whether it could be used to reliably assess kidney pathology, including diabetic nephropathy.

METHODS

We investigated 59 radical nephrectomies to determine the PAB characteristics, whether the PAB is representative of distant nonneoplastic parenchyma, and if diabetic nephropathy could be reliably detected in the PAB.

RESULTS

Mesangial sclerosis was detected within the PAB in 100% of cases with mesangial sclerosis in the distant parenchyma. Eighty percent had a history of diabetes. The PAB exhibited increased glomerular sclerosis (51% vs 13%, P < .001) and interstitial fibrosis and tubular atrophy (83% vs 13%, P < .001) compared with distant parenchyma.

CONCLUSIONS

Diabetic nephropathy can be reliably detected in the PAB, which is important in partial nephrectomies or renal mass biopsies without ample distant renal parenchyma. The degree of glomerular and tubulointerstitial scarring within the PAB does not reflect the overall degree of chronic kidney disease.

Association of Ancillary Pathology Findings in Non-neoplastic Renal Parenchyma and Renal Outcomes of Robotic-Assisted Partial Nephrectomy

Background: To evaluate robotic-assisted partial nephrectomy (RAPN) renal outcomes associated with ancillary pathology findings in non-neoplastic renal parenchymal tissue. Methods: Tissue samples from 378 RAPNs were analyzed for glomerular disease (GD), vascular disease (VD), and tubulointerstitial disease (TD). One hundred and fifty-two patients were excluded due to insufficient non-neoplastic tissue for analysis and 4 patients were excluded due to calyceal diverticulum. Non-neoplastic tissue was evaluated for GD (negative, moderate, or global), VD (absent, mild, moderate, or severe), and TD (present or absent). Associations of ancillary pathology factors with patient characteristics were explored using the non-parametric Kendall tau-test and propensity score adjusted longitudinal mixed effects regression models were used to evaluate associations of these pathology factors with changes in estimated glomerular filtration rate (eGFR) following RAPN. Results: One hundred and fifty-three (68.9%) patients had hypertension and 50 (22.5%) patients had diabetes. The majority of patients did not have any GD (N = 158, 71.2%) or TD (N = 186, 83.8%) while 129 (58.1%) had VD. VD was categorized as absent (N = 93, 41.9%), mild (N = 45, 20.3%), moderate (N = 76, 34.2%), and severe (N = 8, 6.8%). Older age (P = 0.018), hypertension (P < 0.001), and high grade MAP score (P = 0.047) were associated with a higher number of ancillary pathology factors. High grade MAP score (P = 0.03, P = 0.002) and hypertension (P = 0.02, P < 0.001) were individually associated with GD severity and VD severity, respectively. Older age was also individually associated with VD severity (P = 0.002) and hypertension was associated with TD (P = 0.04). Moderate-to-severe VD was associated with a worse change in eGFR from pre-RAPN to 1-month post-RAPN compared to those with mild or no VD (difference in mean change, -3.4 ml/kg/1.73m²; 95% CI, -6.6 to -0.2 ml/kg/1.73m²; P = 0.036). Conclusions: Moderate-to-severe VD in non-neoplastic renal parenchyma is associated with post-operative changes in eGFR. Older age, hypertension, and high grade MAP scores are associated with the number of ancillary pathologies observed in RAPN specimens.