Sarcoidosis is a granulomatous disease of unknown etiology that occurs most often in the 20 to 40-year age group. It will affect the lungs in 90% of patients and may be multiorgan disease. It will usually present with bilateral hilar adenopathy, with or without parenchymal abnormalities. Many cases are asymptomatic and are discovered on routine chest radiographs. Elevated ACE levels and immunoglobulins are associated with active sarcoid lesions. Gallium scans will "light up" in areas of disease activity. Noncaseating granulomas on histology in a patient with the appropriate history are diagnostic of the disease. Tuberculosis and fungal infections must be ruled out in all cases where a tissue diagnosis is obtained. Corticosteroids are considered the firstline treatment for sarcoid symptoms. Asymptomatic disease will often spontaneously resolve without steroids, whereas a few patients will go on to have a chronic, unremitting course of deteriorating lung function despite steroids and will eventually succumb to their lung disease.