Second surgery for renal relapse after nephron sparing surgery: Review of seven cases

Objective: Anatomo-pathologic review of the cases which underwent a second surgery operation for a renal neoplasm relapsed after conservative surgery, in order to find possible relations with the surgical technique. Patients and methods: At our institution nephron sparing surgery (NSS) is currently indicated for neoplasms smaller than 4 centimetres in diameter. The technique involves the removal of the neoplasm with a margin of healthy parenchyma and with the perilesional fat. Patients are firstly monitored by a CT check after 4 months and then with ultrasound/CT checks every 6 months in the first 2 years and then once a year. In this study we analyze in the 1994-2005 period the records of cases undergoing a second operation for a renal tumour relapsed in the operated kidney after NSS. All specimens were reviewed by an individual experienced uro-pathologist who determined the size of surgical margins and relations between the site of the recidivism and the site of the preceding NSS procedure. Results: Seven cases with renal relapse have been found out of 267 undergoing conservative surgery in the same period (incidence 2.6%). The diagnosis has always been made in the lack of other localizations of disease at a complete re-staging and the average latency of the relapse was 19.4 months (8-46 months). In 5 cases the second tumour has been found in the site of the previous NSS: for these cases the minimum margin of the enucleo-resection was lower then 3 millimetres (median minimum margin 1.6 mm). Differently, in the remaining 2 cases, both with a wider surgical margin (median minimum margin 12.0 mm), the site of the first and that of the second neoplasm were distant. In particular, in one case a multifocal recidivism with a spread microvascular embolisation has been found, while in the other the primary neoplasms and the relapse presented a different histotype. Conclusions: In the 5 cases with a narrow resection margin and relapsing tumour in the site of the enucleo-resection one can hypothise the persistence of a peritumoral microscopic neoplastic disease. In the other 2 cases with a wider surgical margin the relapse can be attributed to the widespread microscopic multifocality in one case and to the development of a second de novo neoplasm in the other one. The extension of the surgical margin seems then to have played a role in determining a relapse in the site of enucleo-resection.