Beryllium and its compounds can cause pulmonary interstitial fibrosis via unknown mechanisms. Long non-coding RNA (lncRNA) has been linked to a number of diseases. Chronic beryllium disease (CBD) is a granulomatous lung disease that can be pathologically and clinically indistinguishable from pulmonary sarcoidosis unless immunologic testing, such as the beryllium lymphocyte proliferation test, is performed (BeLPT). The pulmonary manifestations of CBD, like sarcoidosis, are variable and overlap with other respiratory diseases. CBD is definitively diagnosed when there is evidence of immune sensitization to beryllium, as well as diagnostic bronchoscopy with bronchoalveolar lavage and trans bronchial biopsy. CBD can, however, be diagnosed on a medically probable basis in beryllium-exposed patients with consistent radiographic imaging and clinical course. Beryllium workers who were exposed to much higher levels of beryllium in the past demonstrated a much more severe disease than is typically seen today. In these historical cohorts, some extra pulmonary manifestations similar to sarcoidosis were observed, albeit on a narrower spectrum. Extra pulmonary CBD manifestations are uncommon today. Because Lung-predominant sarcoidosis can be very similar to CBD, CBD is still misdiagnosed as sarcoidosis when current or previous beryllium exposure is not recognised and no BeLPT is obtained. This article discusses the similarities and differences between CBD and sarcoidosis, as well as clinical and diagnostic features that can assist physicians in considering CBD in patients with lung-predominant sarcoidosis. The lungs may become sensitised to beryllium after a single or repeated inhalation exposure. Berylliosis develops and progresses slowly. Some people who are allergic to beryllium may not experience symptoms with continued exposure, small Inflammatory nodules known as granulomas form. A 2006 study found that reducing beryllium inhalation did not result in a reduction in CBD or beryllium sensitization, implying that beryllium inhalation was not the only form of exposure and that skin exposure was also a cause. Granulomas are seen in other chronic diseases such as tuberculosis and sarcoidosis, and it can be difficult to distinguish berylliosis from these conditions at times. However, CBD granulomas are typically non-caseating, that is, they are not characterised by necrosis and thus do not have a cheese-like appearance. Sarcoidosis (also known as Besnier-Boeck-Schaumann disease) is a disorder characterised by abnormal collections of inflammatory cells that form granulomata. Typically, the disease begins in the lungs, skin, or lymph nodes. The eyes, liver, heart, and brain are less frequently affected. However, any organ can be affected. The signs and symptoms vary according to the organ involved. Symptoms are frequently absent or mild. When it affects the lungs, it can cause wheezing, coughing, shortness of breath, and chest pain. Some people have Löfgren syndrome, which is characterised by fever, enlarged lymph nodes, arthritis, and an erythema nodosum rash. Sarcoidosis has no known cause. [Some speculate that it is the result of an immune response to a trigger, such as an infection or chemicals, in those who are genetically predisposed.