Gangliocytic paraganglioma.

Six cases of upper intestinal gangliocytic paraganglioma, five in the duodenum and one in the jejunum, are reported. Three histologic patterns, each comparable to patterns in paraganglioma, ganglioneuroma, or carcinoid-islet cell tumor, are mixed in varying proportions. The complex histologic patterns encountered within these tumors reflect the differentiation of pluripotent cells. Although the parent cell is not identified in this study, gangliocytic paragangliomas may arise from cells which normally reside in the mucosal crypts and are presumably derived from cells originating in the neural crest. Three of the six tumors contain stromal amyloid. In one case, studied by electron microscopy, dense-cored cytoplasmic vesicles almost fill some of the tumor cells. Gangliocytic paragangliomas share the features of stromal amyloid and dense-cored vesicles with other neurocrine tumors.