Sarcoidosis. Coloured frontal chest X-ray of the lungs of a patient with pulmonary sarcoidosis. Affected lung tissue shows up as opaque white patches (left and right of centre). Also known as Boeck's disease, this is a chronic inflammation of the lymph nodes or organs. It causes multiple granulomas (nodular growths), which are similar to the tubercles formed in tuberculosis. 90 percent of sarcoidosis affects the lungs, targeting the hilar (bronchopulmonary) lymph nodes. The disease has no known cause and medical intervention is not always necessary, but if required is in the form of corticosteroid drugs to reduce inflammation.