[Mucus plugs. Phantom tumour of the major air passages. The tomographic appearances(author's transl)].

During tomography of the major air passages, the radiologist is occasionally surprised by an appearance which is indistinguishable from an intraluminal tumour. In addition to a genuine tumour, one must then consider the possibility of a mucus plug. One can distinguish between these possibilities by repeating the appropriate cuts after the patient has coughed several times. It will then be found that the position or appearance of the mucus plug will have altered, or that it will have disappeared completely. This phenomenom occurs primarily in older patients, or patients unable to cough. We report ten such cases.