[A 7-case anatomopathology revision in the presence of renal relapse after conservative therapy: implications on...

Anatomopathology revision of the cases which underwent second surgery because of a renal neoplasm relapsing after conservative surgery, in order to find possible relations with the surgical technique. MATERIALS AND METHODS. At our institution, Nephron-sparing surgery (NSS) is currently indicated as elective technique for neoplasms smaller than 4cm in diameter. The technique involves the removal of the neoplasm with a margin of healthy parenchyma and with the perilesional fat. The patients are monitored with a first 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 the present study we analyze the records of the cases in the period 1994-2005 undergoing a second operation for a renal tumor relapsing in the operated kidney after NSS. All specimens were reviewed by a single experienced uro-pathologist, who determined the size of the surgical margins and the relations between the seat of recidivism and the seat of the preceding enucleoresection. RESULTS. Seven cases with renal relapse were found out of 267 undergoing conservative surgery in the same period (incidence: 2.6%). The diagnosis had always been made lacking any other disease localizations at a complete re-staging; the average relapse latency was 19.4 months (8-46 months). In 5 cases the second tumor was found in the seat of the previous NSS: for these cases the minimum margin of the enucleoresection was lower than 3mm (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 seat of the first and that of the second neoplasm were distant. In particular, in one case a multifocal relapse with a spread microvascular embolization was found, while in the other the two neoplasms showed a different histotype. DISCUSSION AND CONCLUSIONS. In the 5 cases with a little resection margin and relapsing tumor in the seat of the enucleoresection, the persistence of a peritumoral microscopic neoplastic disease can be assumed. In the other 2 cases showing 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 case. The extension of the surgical margin seems then to have played a role in determining a relapse in the seat of enucleoresection.