Pulmonary sarcoidosis.

Sarcoidosis is an inflammatory granulomatous disease that is characterized by diverse organ system manifestations, a variable clinical course, and a predilection for affecting relatively young adults worldwide. Abnormalities on chest radiographs are detected in 85% to 95% of patients who have sarcoidosis. Approximately 20% to 50% of patients who have sarcoidosis present with respiratory symptoms, including dyspnea, cough, chest pain, and tightness of the chest. The clinical course and manifestations of pulmonary sarcoidosis are protean: spontaneous remission occurs in approximately two thirds of patients; up to 30% of patients have chronic course of the lung disease, resulting in progressive, (sometimes life-threatening) loss of lung function. Morbidity that correlates to sarcoidosis occurs in 1% to 4% of patients.