This photo shows subpleural non-caseating granulomas and fibrosis in a case of pulmonary sarcoidosis. The patient had involvement of the lungs, hilar lymph nodes, and myocardium. See other photos from this patient in the cardiovascular and lymph-related sections of this website.

Sarcoidosis is characterized by the formation of noncaseating granulomas in various organs. Though an infectious basis seems likely, the cause of the disease is still unknown.There is a 10-17 fold increased incidence in African-Americans as compared with Caucasians. The disease has a highly variable course with a mortality rate of 1-6%. There is usually pulmonary and/or cardiac involvement in fatal cases. The lungs are involved in most cases; symptomatic in one-half to one-third. Disease in the lungs is characterized as stage I if bilateral hilar lymphadenopathy alone is present, stage II if there are also pulmonary infiltrates, stage III if there are only pulmonary infiltrates, and stage IV if there is extensive pulmonary fibrosis. Anterior uveitis is a common finding. The myocardium is involved in 5% of patients. Cardiac manifestations can include heart block, arrythmias, or congeative heart failure. A myocardial infarction can be simulated. The skin and nervous system are prominent among the many other sites of involvement. One-half of patients have an elevated serum calcium level and 60% have an elevated serum ACE level.

Contributed by Dr. Robert Van Wesep