Abstract
It is a well established fact that the sympathetic nervous system appears relatively early in the embryo as primordia of cells of neural crest origin and in critical stages of embryonic development these cells can be traced to their definitive regions. According to the conception of Kuntz (1), the sympathetic pri-mordium consists of cells which are peripherally displaced from the ventral nerve roots as well as from the neural crests. A critical examination of the cells of the sympathetic primordia shows distinctly that these elements are totally undifferentiated, being spherical in shape, possessing round chromatin-rich nuclei surrounded by scanty protoplasm. They have often been described as “lymphoid” cells or sympathogonia. These cells change into slightly larger cells with more vesicular nuclei and a wider rim of clear cytoplasm, the sympathoblasts, which, according to Bailey (2), are pluripotential and may give rise to: ( a ) neuroblasts, from which the ganglion cells of the sympathetic system develop; ( b ) pheochromoblasts, the progenitors of the pheochromocytes of the adrenal medulla and of the paraganglionic bodies; ( c ) immature glial cells of the sympathetic system, the astroblasts, which ripen into mature supporting units, astrocytes. Neoplasms containing one or several of these cell types, namely, sympathogonia, sympathoblasts, neuroblasts, ganglion cells, pheochromoblasts, pheochromocytes, astroblasts, and astrocytes, are being more frequently reported in the literature. Due to the fact that the sympathetic system is developed by a progressive growth and differentiation from pluripotential mother cells, it is to be expected that tumors arising during the process of differentiation may contain cells in varying degrees of maturity, thus producing new growths difficult of classification. On the other hand, one should anticipate finding tumors containing a single cell type, in which case the diagnosis should be relatively easy. A study of the cases reported bears out this supposition, for since these tumors were first definitely associated with the sympathetic system by Wright (3), in 1910, the nomenclature has continued to grow in complexity.
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