Abstract
Early investigators, including Pepper1 and Hutchinson,2 considered the group of smallcell malignant neoplasms now known as neuroblastomas to be sarcomas. It was not until 1891 that Marchand3 pointed out their neurogenic origin, which was even more strongly stated by Wiesel4 in 1905. Finally in 1910, Wright5 established once and for all the identity of the neuroblastoma which he compared to the embryonic adrenal medulla and to the embryonic sympathetic system. It remained for Herxheimer,6 in 1914, to apply Bielschowsky's silver technique to these tumors and to prove for the first time that the fibrils indeed were fine unmedullated nerve fibers. It is the purpose of this brief paper not only to demonstrate unmedullated nerve fibers in a metastatic neuroblastoma examined by electron microscopy but also to demonstrate synaptic structures ending on tumor cells and their processes. Materials and Methods A neuroblastoma arising in the