The authors present a case of a 62-year old male, who palpated a small resistance on the external side of his right arm above the elbow and the palpation or compression of which produced paraesthesias in the area of the superficial branch of the radial nerve.EMG examination did not show evidence of motor or sensory lesion of the right radial nerve. Ultrasound examination detected a solid spherical mass in the lateral intermuscular septum above the elbow. Because of persisting symptoms and growth of the mass, an MRI exam was performed and showed a focus of 9 x 12 x 10 mm above the lateral epicondyle, widely connected to the sheath of the radial nerve, sharply demarcated against the surrounding tissue. In T2-weighted images, the focus was homogeneously intense with a hypointense margin. After i.v. contrast application, the focus enhanced. Based on morphology and signal characteristics, a suspicion for schwannoma was made. Four months after the appearance of the symptoms, the patient underwent surgery. During the procedure, the radial nerve was isolated and after incision of the epineurium, a neurinoma was extirpated in parts. Histological examination confirmed a schwannoma (neurinoma) of type Antoni B.

        Key words: peripheral nerve tumours, schwannoma, radial nerve, MRI examination of peripheral nerves