Pathogenesis of sarcoidosis.

Sarcoidosis is a multisystem granulomatous disease of unknown etiology. The organs that are involved by sarcoidosis include the lungs in which the granuloma is seen in more than 90% of patients to the pituitary, which is only rarely affected. There are many hypotheses as to the cause of sarcoidosis. Some of them rely on the similarities seen between sarcoidosis and the other granuloma-forming diseases such as tuberculosis, berylliosis, pine pollen inhalation and acute and chronic bacterial and viral infections, while others find similarities between sarcoidosis and immune reactions observed in autoimmune disorders. Still other explanations implicate a genetic predisposition or a still-unknown agent as the underlying cause of the granuloma formation.