[Thoracic sarcoidosis]

Sarcoidosis is a multisystemic granulomatous disease of unknown etiology. It mainly affects the thoracic lymph nodes and the lungs. The staging of sarcoidosis, which classifies patients according to their probability of spontaneous remission, is based on the plain chest film findings. Plain chest films are not as sensitive as high resolution computed tomography (HRCT) at detecting involvement of the lymph nodes, lungs, or bronchi. The high resolution CT findings can be typical, practically pathognomic, or atypical. High resolution CT provides information about the activity of the disease and detects incipient signs of fibrosis and other complications. To reach the diagnosis, it is necessary to correlate the clinical and radiological findings (and often the histological findings). Cardiac involvement can cause sudden death. The diagnosis of cardiac involvement is difficult; it is based on various imaging tests, like magnetic resonance imaging, which is more specific, and positron emission tomography. Diagnostic confirmation by endomyocardial biopsy is obtained in few patients.