In the February 2009 issue of CHEST, McNeill and coworkers1 reported on the association of sarcoidosis and non-small cell lung cancer in a middle-aged man and discussed the clinical roles of CT scanning, PET scanning, endoscopic ultrasound fine-needle aspiration, and transbronchial needle aspiration in mediastinal staging. The relationship between sarcoidosis and cancer is intriguing, and epidemiologic studies2 have produced inconclusive results. Moreover nonnecrotizing granulomas have been described in patients with many types of malignancy (eg, lymphoma, testicular cancer, head and neck cancer, gastric cancer, renal cancer, and breast cancer). Granulomas have been found surrounding the primary tumor (3 to 7% of cases) or in the draining lymph nodes (4.4% of cases)3 and probably reflect an immune response to tumor antigens. Many authors refer to this finding as sarcoid reaction. On the other hand, true sarcoidosis is a multisystem granulomatous disease mainly involving the lung and mediastinal nodes. The diagnosis requires a compatible clinicoradiologic picture, the demonstration of nonnecrotizing granulomas, and the exclusion of other causes of granulomatous inflammation.