[For a better diagnostic strategy in idiopathic diaphragmatic paralysis].

The authors report a case of right-sided paralysis of the diaphragm which revealed a lung cancer extending to the mediastinum and involving the right phrenic nerve. This case underlines the limitations of thoracic imaging in case of phrenic nerve paralysis. It also demonstrates the value of early exploratory thoracotomy in all patients with allegedly "idiopathic" unilateral phrenic nerve paralysis.