A diagnosis of sarcoidosis is established on the basis of compatible clinical and radiologic findings and histologic evidence of the presence of noncaseous epithelioid cell granulomas in one or more organs and the absence of causative organisms or particulates (16). Granulomas of known causes and local sarcoidlike reactions must be excluded. Granulomatous lesions may result from many conditions, including tuberculosis, berylliosis, leprosy, hypersensitivity pneumonitis, Crohn disease, primary biliary cirrhosis, and fungal disease. Moreover, local sarcoidlike reactions may be seen in lymph nodes that drain a neoplasm or a site of chronic inflammation (19). Such reactions also have been seen in patients who have undergone chemotherapy and radiation therapy (23).
If biopsy of lymph nodes or pulmonary or pleural tissue is necessary for diagnosis, one of three techniques may be used: transbronchial biopsy, CT-guided biopsy, or surgical biopsy (24). The use of a surgical technique may be warranted when the results of biopsy with another procedure are not definitive and biopsy of mediastinal lymph nodes, lung, or both is required. This can generally be done with minimally invasive procedures, such as cervical mediastinoscopy, the Chamberlain procedure (a parasternal minithoracotomy for biopsy of the aortopulmonary window or para-aortic nodes), or video-assisted thoracoscopic surgical biopsy (25).