The cases reported here are presented to call attention to the clinical aspects of a rare type of neoplasm, which has been studied chiefly heretofore from its histologic and pathologic aspects. There must have occurred many more cases in this country than have been described, and it is to be hoped that more of them will be recognized and studied so that our knowledge of the biologic behavior of the neoplasm may increase. Of the two new cases dealt with in this communication, one seems to have come from the cervical and the other from the thoracic sympathetic ganglions. Accordingly, all the ganglioneuromas occurring in those situations of which records could be found have been studied together with them, so that this paper may be said to contain a summary of most of the known clinical observations that have been made. The best studies of ganglioneuromas in English are contained