Sarcoidosis

Sarcoidosis is a disease of unknown etiology believed by some to be a hyperimmune form of tuberculosis. Granulomatous lesions resembling tubercles without casea­tion develop in the regional and medi­astinal lymph nodes, in the spleen and in the bones and skin. The disease as a rule pursues a slow, benign course, with spon­taneous healing. More rarely a fatal course is observed with involvement of the lungs, nervous system and the heart. Lymphadenopathy and splenomegaly are usually present. The osseous lesions produce foci of bone resorption. When the uveal tract of the eye and the parotid glands are in­volved the condition is known as Heerfordt's syndrome. Involutional changes in the granulomatous nodules may result in the deposition of amyloid. A significant number of patients have a falsely positive Wassermann reaction and an unexplained increase in plasma globulins.