Sarcoidosis is a disease of unknown cause characterized by the formation of immune granulomas.
Many organs may become affected. The proceeds insidiously. The diagnosis is sometimes made fortuitously upon routine chest radiography or that done for other reasons. The age of onset is typically adolescents to young adults. Lung involvement is common and symptoms may include a cough, dyspnea and chest pain. Extrapulmonary symptoms may include the skin, joints, and eye findings. Bilateral hilar adenopathy is the classic finding on chest radiograph. Anemia or other cell line deficiencies, elevated liver enzymes, hypercalciuria, and EKG abnormalities may also be present. Angiotensin-converting enzyme levels may be elevated but are not diagnostic. General features may be tiredness, fever, muscle pain, sleeping problems, weight loss and night sweating.
Histopathological confirmation of noncaseating granulomas is essential for diagnosis. It is generally performed through a biopsy of the most peripheral site possible, although transbronchial biopsy is commonly required. Finally, other possible etiologies must be evaluated and differentiated with a particular emphasis on tuberculosis due to the multiple overlapping symptoms and findings. Unfortunately, sarcoidosis is frequently misdiagnosed.
Newer techniques such as proteomics and transcriptional gene signatures may contribute to the understanding of the pathophysiology of sarcoidosis, and may even serve as diagnostic tools in the future.
Sarcoidosis is a multisystemic disorder of unknown cause characterized by the formation of immune granulomas in involved organs.