Extrapulmonary sarcoidosis: A chameleon disease at imaging

There is great attention in the literature given to the diagnosis of pulmonary sarcoidosis (SA), where it is established that the combination of factors such as suggestive history, clinical picture, imaging features at computed tomography (CT) such as restrictive disease and lymph nodes enlargement, and (when available) histopatological examination of lung tissues can orient toward the correct diagnosis [1]. In clinical practice, the reality is that the diagnosis of SA is never sure, several disorders can manifest indeed with similar findings [2], and the SA diagnosis can be defined often only “highly probable” when alternative causes are excluded [1, 3]. Also biopsy of the examined tissue can highlight common features of other disorders such as tuberculosis, and sarcoid-like patterns can be found in these patients, going to complicate even more the picture [4-6]. This concept is more true when there is an isolated involvement of extrapulmonary tissues. Organs such as the heart, liver, spleen and the gastroenteric tract can be affected in a not negligible percentage, and clinical manifestations can overlap with those of other diseases (e.g. heart disease with heart dysfunction and myocarditis, liver and spleen with steatosis, splenomegaly and diffusion of parenchymal nodules) and imaging features are not always characteristic to give clues for a presumptive diagnosis [7, 8]. Focal and hypodense lesions can be found as well as non-specific organ enlargement, and these features alone give no elements for a correct diagnosis. These lesions can be easily misdiagnosed with other disorders such as tuberculosis, lymphoma and malignant disease, and the aid of contrast agents can give only a presumptive idea of tissue composition, but not a real estimation of the diagnosis of nature [9-11]. © 2019 Bentham Science Publishers.