Frequency of capsular invasion and prenephric fat infiltration in renal cell carcinoma after partial nephrectomy

Background and Objective: Nowadays, partial nephrectomy (PN) has specific indications in renal tumors. There are challenges regarding the remaining and seeding of malignant cells after surgery due to increasing tendency to do laparoscopic PN (LPN) and consequently increased manipulation of the surrounding tumor tissue. The objective of this study is to investigate the frequency of renal capsule invasion (RCI) and perinephric fat infiltration (PFI) in patients with renal cell carcinoma (RCC) who had underwent PN. Materials and Methods: Clinical data and pathologic samples of 101 patients who underwent PN and had RCC from 2011 to 2012 were elicited. Sixty one patients underwent LPN and 40 patients underwent open PN (OPN). All pathologic samples reviewed by an uropathologist. Fuhrman nuclear grade, surgical margin and prevalence of RCI and PFI were also determined. Results: The mean tumor size was 40.7 mm (range: 15mm to 120mm). In all cases, the renal capsule and perinephric fat were left intact. Surgical margin was involved in four cases of LPN. Three patients had recurrence during follow up time (follow up durations were 12, 16, and 24 months for each). The fourth one was expired during 30 months follow up despite performing radical nephrectomy. Conclusions: Based on the results obtained in this study, the probability of RCI and PFI is low and hence manipulating and removing the perinephric fat to achieve better exposure to tumor will not increase the risk of seeding malignant cells.