Gangliocytic paraganglioma in association with a duodenal diverticulum.

Gangliocytic paraganglioma is an extremely rare benign neurogenic tumor nearly exclusively located in the second portion of the duodenum, also the most common site of duodenal diverticula. A case is reported of a gangliocytic paraganglioma presenting in a 65-yr-old woman with a 1-yr history of postprandial cramping abdominal pain culminating in a single episode of melena leading to laparotomy. The tumor was identified with difficulty by endoscopy following negative barium studies. Histologically, the tumor is composed of carcinoid-like cells admixed with varying numbers of ganglion cells in a substratum of neuroid spindle cells. The epithelioid cells contain argyrophilic cytoplasmic granules confirmed by electron microscopy to be dense core membrane-bound secretory granules. Review of the literature suggests the tumor described is typical both clinically and pathologically of gangliocytic paraganglioma of the duodenum, except for its unprecedented occurrence in association with a duodenal diverticulum.