Sarcoidosis and chronic beryllium disease: similarities and differences.

Chronic beryllium disease (CBD) is a granulomatous lung disease that may be pathologically and clinically indistinguishable from pulmonary sarcoidosis, except through use of immunologic testing, such as the beryllium lymphocyte proliferation test (BeLPT). Similar to sarcoidosis, the pulmonary manifestations of CBD are variable and overlap with other respiratory diseases. Definitive diagnosis of CBD is established by evidence of immune sensitization to beryllium and diagnostic bronchoscopy with bronchoalveolar lavage and transbronchial biopsy. However, the diagnosis of CBD can also be established on a medically probable basis in beryllium-exposed patients with consistent radiographic imaging and clinical course. Beryllium workers exposed too much higher levels of beryllium in the past demonstrated a much more fulminant disease than is usually seen today. Some extrapulmonary manifestations similar to sarcoidosis were noted in these historic cohorts, although with a narrower spectrum. Extrapulmonary manifestations of CBD are rare today. Since lung-predominant sarcoidosis can very closely resemble CBD, CBD is still misdiagnosed as sarcoidosis when current or past exposure to beryllium is not recognized and no BeLPT is obtained. This article describes the similarities and differences between CBD and sarcoidosis, including clinical and diagnostic features that can help physicians consider CBD in patients with apparent lung-predominant sarcoidosis.