[Lesions of the peripheral nervous system in the treatment of breast cancer].

On the basis of our own patients, the anamnestic data and the neurological constellation in late radiogenic paresis (the most frequent peripheral nervous condition in treatment of mammary carcinoma) are described. A comparison with the situation in metastatic infiltration of the brachial plexus shows the great difficulties in differential diagnosis. Pain can be observed more frequently in metastatic plexus infiltration. The presence of a Horner syndrome can be regarded as decisive evidence for recurrent growth of a carcinoma. If a Horner syndrome is absent, tumor growth can be demonstrated conclusively only by biopsy or surgical exploration. The most frequent condition which is not connected with mammary carcinoma and its followup treatment, but which can stimulate a late radiogenic paresis of the brachial plexus is the carpal tunnel syndrome. Whereas a certain differentiation is not always possible on the basis of the anamnesis and clinical findings, a clear discrimination is possible by means of electrophysiological investigation techniques.