[A difficult diagnosis].

The patient information and obtaining their consent before any therapeutic constitute a basis for medicine exercise. However, there are situations where the physician may be in default. In that case, concepts of benefit/risk balance, of clear and appropriate information, and of legal liability for medico-surgical staff takes all their magnitude. That was the case in our observation, with a 69 years old patient with history of smoking, presenting a suspicious lung opacity which will require, following an agreement by multidisciplinary meeting, an exploration by thoracotomy despite an acceptable but altered respiratory function, as a result of a post-smoking broncho-emphysema. The non-malignant character of the suspected lesion raise questions about the risks involved, the benefit/risk balance, and the legal risk scopes of the medicosurgical staff as defined in the Cancer programme framework.