Gangliocytic paragangliomas of the duodenum.A report of two cases with light and electron microscopic examination

Two cases of benign polypoid tumors of the duodenal submucosa are reported. Both were located in the second portion of the duodenum. The first was found incidentally during surgery for a pyloric ulcer; the second became itself superficially ulcerated and gave rise to clinical symptoms. The tumors were composed of clusters and ribbons of columnar epithelioid cells with transitions to more spindly elements and to well-developed ganglion cells. Nerve fibrils could be impregnated emanating from all these cell types. Under the electron microscope (case 1), the ganglion cells as well as the epithelioid and spindly elements contained granules with a central dark core and a membranous envelope characteristic of catecholamine granules. These tumors have light and electron microscopic features seen in paragangliomas as well as ganglioneuromas. They differ from the chemodectomas as seen in the carotid body or glomus jugulare area by: 1. the absence of a chemoreceptor organ in the normal duodenum, 2. the very large number of nerve cells and precursors in the duodenal tumors, sometimes giving the appearance of a ganglioneuroma, and, 3. the so far uniformly benign behavior of these tumors in contrast to the known occurrence of malignant paragangliomas in other parts of the body. The name “gangliocytic paraganglioma” is suggested for these duodenal lesions. We believe, with Taylor and Helwig, that these lesions represent a transitional or hybrid form of tumor between gangliocytomas and the nonchromaffin paragangliomas.