Imagerie des tumeurs du médiastin

Imaging of mediastinal tumors is an important part of the diagnostic workup in patients presenting symptoms suggestive of compression of one or more of the mediastinal components. In other cases, lesions growing within the mediastinum remain asymptomatic and are diagnosed when chest X-ray or CT are routinely performed for other indications. CT remains the most available and reliable tool among the different imaging methods. Due to its permanent technical improvements, it can be used as the one-step answer to all the requirements of the pretherapeutic evaluation of a mediastinal mass. Chest plain film is still needed as the first line examination in order to carefully select the acquisition protocol for CT. MR did not demonstrate any superiority to CT except for the preoperative workup of lesions arising in the posterior part of the mediastinum. MR remains an interesting tool for tissue characterisation. Topography of mediastinal lesions (based upon the definition of mediastinal compartments) is one of the guides through the diagnostic pathway in imaging these tumors. The other one is their main tissue component, so that cystic, fatty and soft tissue masses can be differentiated.