Sarcoidosis is a systemic disease characterized by abnormal tissue swellings throughout the body.
These swellings are called granulomas and are most commonly found in the lungs, liver, spleen, and skin. However, they may be found anywhere, including the eyes, ears, bones, and even in the coverings around the brain and spinal cord. Although these granulomas are usually widespread, they are very small and can only be seen with the aid of the microscope. The cause of sarcoidosis is completely unknown. At one time pine pollen was thought to be the cause since many of the cases were found in people who lived near pine forests.