PATHOLOGICAL CHARACTERISTICS AND PROGNOSTIC IMPACT OF PERITUMORAL CAPSULE PENETRATION IN RENAL CELL CARCINOMA AFTER TUMOR ENUCLEATION

Scopo del lavoro To evaluate the pathological characteristics of peritumoral capsule and the prognostic impact of capsule penetration on tumor recurrence in patients treated by tumor enucleation (TE) for RCC. Materiali e metodi Between January 2005 and June 2011, 304 consecutive patients with single sporadic intracapsular RCC had TE. Peritumoral capsule status was carefully analyzed by two dedicated uropathologists. The degree and the side of capsule penetration if present were evaluated. Risultati According to the peritumoral capsule status, of the 304 RCCs, in 155 (51%) the peritumoral capsule was intact and free from neoplastic penetration (PC-) while in 149 (49%) there were signs of penetration within its layers. Overall, 34.9% had capsular penetration on the parenchymal side and of those 75 (24.7%) had penetration only (PCK+) and 31 (10.2%) had capsular penetration and invasion beyond it (PCK++). Whereas, 14.1% had peritumoral capsule invasion on the perirenal fat tissue side and of those 18 (5.9%) had capsular penetration (PCF+) and 25 (8.2%) had penetration and invasion beyond it (PCF++). None of the patients had positive surgical margins detected at the pathologic examination. Mean (median, range) follow up was 49 months (46, 25-69). During the study period, 13 (4.3%) patients had progressive disease. The 5-year progression-free survival rate for RCC according to PC status was: PC- 97.5%, PCK+ 98.2%; PCK++, 92.8%; PCF+, 82.6%; PCF++, 74% (p Discussione The presence of a capsular involvement could represent the first pathological evidence of the capacity achieved by tumor cells to infiltrate and invade normal parenchyma and perirenal tissue, and might potentially increase the risk of local and systemic recurrence and could eventually be used as a prognostic factor in patients with clinically intracapsular RCC amenable for conservative surgery. Conclusioni TE is an oncologically safe NSS technique. PCF is a significant and independent predictor of tumor recurrence in patients with clinically intracapsular RCCs scheduled for NSS and appear to be a stronger predictor than TNM stage. PCK does not predict the risk of recurrence.