Sarcoidosis. Light micrograph of a section through a lymph node affected by sarcoidosis. Also known as Boeck's disease, this is a chronic inflammation of the lymph nodes or organs. It causes multiple granulomas (nodular growths, upper centre) to form in body tissue. The most commonly affected organs are the lungs and skin. The disease has no known cause. Medical intervention is not always necessary, but if required is in the form of corticosteroid drugs to reduce inflammation.