Features of Ipsilateral Renal Recurrences After Partial Nephrectomy: A Proposal of A Pathogenetic Classification

Abstract Background Poor data are reported on the pathogenesis of ipsilateral relapse (IR) after partial nephrectomy (PN). The objective of this study was to investigate features of IR after PN with the intention to propose a pathogenetic classification. Materials and Methods Retrospective consultation of an institutional database that stores the data of 683 patients submitted to PN since 1993. The clinical, radiological, and follow-up data of the cases submitted to salvage nephrectomy due to an IR were analyzed. The slides of the sections from the tumor-parenchyma interface of PN and the bed of resection from the specimen of nephrectomy were reviewed. Results Eighteen patients were submitted to salvage nephrectomy for an IR. In 12 cases the IR harbored into the site of PN and a mixture of cancer cells and granulomatous reaction was found at the resection bed (IR type A). In the remaining 6, in microscopy of the resection bed was found only fibrosis: 3 of these cases had a clear-cell renal cell carcinoma (RCC) with diffuse microvascular embolization and the relapse in the same portion of the kidney of the primary tumor (IR type B); the other 3 had a non–clear-cell RCC and the primary and relapsing tumors were located in distinct portions of the kidney (IR type C). Six patients (4 IR type A, 2 type B) had a further progression and 5 of them died due to RCC. Conclusion More frequently an IR is due to the incomplete resection of the primary tumor (IR type A), in a minority of the cases to the local spread of the tumor by microvascular embolization (IR type B), or true multifocality (IR type C). The prognosis of IR not due to multifocality (type A and B) is poor, despite salvage nephrectomy.