Background: Observational studies suggest a proportion of patients with lymph node metastases will benefit from lymph node dissection (LND) at the time of nephrectomy for clear cell renal cell carcinoma (RCC). Objective: Our aim was to report the performance of five previously identified high-risk pathologic features assessed by intraoperative examination on prediction of lymph node metastases and propose a template for LND based on locations of lymph node involvement. Design, Setting, and Participants: The study included a historical cohort of consecutive patients from a single institution who received LND in conjunction with nephrectomy for high-risk clear cell RCC between 2002 and 2006. Interventions: All patients underwent nephrectomy and LND. Measurements: Patients were considered high risk for nodal metastasis if two or more of the following features were identified during intraoperative pathologic assessment of the primary tumor: nuclear grade 3 or 4, sarcomatoid component, tumor size ≥10cm, tumor stage pT3 or pT4, or coagulative tumor necrosis. Based on these features, LND was performed at the time of nephrectomy, and the numbers and sites of regional lymph node metastasis were recorded for each patient. Results and Limitations: Of the 169 high-risk patients, 64 (38%) had lymph node metastases. All patients with nodal metastases had nodal involvement within the primary lymphatic sites of each kidney prior to involvement of the nodes overlying the contralateral great vessel. A limitation of the study is the lack of a standardized LND performed throughout the study period. Conclusions: Pathologic features of renal tumors are associated with the risk of regional lymph node metastases and lymph node metastases that appear to progress though the primary lymphatic drainage of each kidney. Based on these findings we recommend that when performing LND the lymph nodes from the ipsilateral great vessel and the interaortocaval region be removed from the crus of the diaphragm to the common iliac artery.
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