Mediastinopulmonary sarcoidosis mimicking metastatic renal cell carcinoma: About a case report.

There is a well-established association between sarcoidosis and many solid and hematologic malignancies, but it is less commonly described in patients with renal cell carcinoma. The majority of the cases described presented local sarcoid-like reactions in the immediate vicinity of the tumor with comparatively few reports of the disease further away. In view of the relatively small number of cases, there remains great uncertainty about the clinical behavior of sarcoidosis in renal cell carcinoma. In this observation, we illustrate a case of mediastinopulmonary sarcoidosis, which behaved like a true paraneoplastic syndrome of a renal tumor.