We report a 56 years old male patient presenting with a sympathetic denervation of the right upper limb due to an apical lung cancer. Vasomotor paralysis of the limb was objectively documented with a contact termography. The clinical presentation of this patient was unusual, considering that the alteration occurred without sensory or motor changes of the limb or autonomic disturbances of the face. The absence of clinical and neurophysiological involvement of large and small caliber fibres of the brachial plexus and the lack of autonomic dysfunction of the face was explained by a predominant tumoral infiltration of T2 and T4 ventral roots, which supply autonomic innervation to the upper limbs.