Case studies to explore the pitfalls in the diagnosis of sarcoidosis.

Sarcoidosis is a multisystemic disorder of unknown cause. Diagnosis is established when clinical and radiological findings are supported by histological evidence of noncaseating epitheloid cell granulomas. Exclusion of granulomas of known causes and sarcoidlike reactions is mandatory. A lot of infections may mimic a sarcoidlike granulomatous reaction. Even with well advanced pathological and microbiological examination, it could be hard to make the appropriate diagnosis. Moreover, sarcoidosis patients receiving corticosteroids are susceptible to opportunistic infections. The challenge is, however, making the right diagnosis because opportunistic infections can resemble sarcoidosis. The case reports presented in this paper are meant to stress the importance of excluding granulomatous infections in patients with (suspected) sarcoidosis. Appropriate diagnostic procedures are important to exclude an infectious condition mimicking sarcoidosis. Accordingly, appropriate treatment can start without further delay.