Sarcoidosis is a multisystemic chronic inflammatory disease characterized by noncaseous epithelioid cell granulomas. Involvement of the lung and of bilateral hilar and mediastinal lymph nodes is most common. Atypical patterns include unilateral lymphadenopathy, that can be seen in unusual locations or may become calcified. The most frequent parenchymal pattern of sarcoidosis is a bilateral perilymphatic symmetric distribution of micronodular lesions. Miliary opacities or ill-defined irregular opacities, without air bronchograms, which develop cavitation, with satellite nodules are seen in other granulomatous diseases and neoplasms. Occasionally, parenchymal lesions coalesce, forming multiple well-defined macronodules mimicking a metastatic
process. Stenosis or compression of bronchi may result from endobronchial granulomas, resulting in obstruction and atelectasis. Pleural involvement is rare including pleural effusion, pneumothorax, pleural thickening or calcifications. Thoracic sarcoidosis manifests with various patterns. Atypical manifestations of sarcoidosis may require an extensive differential diagnosis that encloses tuberculosis, silicosis, pneumoconiosis, malignancies, lymphoma, and any other causes of chronic pulmonary infiltrates.
Key words: sarcoidosis, atypical forms, mediastinal lymph nodes.
Sarcoidosis represents a multisystem chronic inflammatory condition characterized by noncaseous epithelioid cell granulomas and changes in tissue architecture, that can affect any organ. Involvement of the lung and the hilar and mediastinal lymph nodes is most usual. (approximately 90% cases)1.