Bilateral pulmonary hilar lymphadenopathy. An unusual manifestation of metastatic renal cell carcinoma.

Four patients with bilateral pulmonary hilar adenopathy secondary to lymphangitic spread from renal cell carcinoma were examined. Two additional cases had adenopathy secondary to nasopharyngeal carcinoma. Patients may initially present with bilateral pulmonary lymphadenopathy or as late as 3 1/2 years after the discovery of the primary renal tumor. The mechanism of lymphangitic spread probably is related to reflux of tumor emboli from the thoracic duct into the bronchomediastinal trunks because of incompetent lymphatic valves. In one case gallium imaging demonstrated bilateral hilar isotopic uptake as well as periaortic uptake.