Hilar lymph node metastasis in renal cell carcinoma.

A 48-year-old man, who underwent a right nephrectomy for renal cell carcinoma 7 years earlier, was found to have hilar lymph node metastasis alone, without lesions, in the pulmonary parenchyma. Chest X-ray and CT findings showed a left hilar mass about 4 x 2.5 cm in diameter. Left bronchial arteriography showed a hypervascular mass lesion in the left hilum. Macroscopic tumor invasion of the pulmonary artery and left main bronchus indicated left pneumonectomy. The resected specimen was found histologically to involve metastatic renal cell carcinoma in the left hilar lymph node about 3 cm in diameter. Tumor metastasis was limited to the lymph node. The metastatic pathway of renal cell carcinoma to the hilar lymph node was considered lymphogenous via either retrograde lymphatic flow from the thoracic duct or through the lymphatics in the inferior pulmonary ligament.