Duodenal gangliocytic paragangliomas: a study of 10 cases with immunocytochemical neuroendocrine markers.

Ten cases of duodenal paraganglioma were studied by conventional histologic and immunocytochemical techniques at both light and electron microscopic levels. Histologically, mixtures of epithelial, ganglion, and spindle cells were seen. In all of the cases immunoreactivity for neuron-specific enolase (NSE) and protein gene product (PGP) 9.5 was seen in each component. Pancreatic polypeptide immunoreactivity was detected in eight cases, mainly in epithelial cells. Somatostatin immunoreactivity was present in epithelial and ganglion cells in nine cases. In seven cases immunoreactivity for neurofilaments, a marker for neurons, was seen in ganglion and spindle cells. However, immunoreactivity for chromogranin, a protein found in endocrine storage granules, was found in only two cases, and the staining was confined to well-granulated epithelial cells. The spindle cells were immunostained only for neuronal markers, NSE and neurofilaments, and the glial marker S-100 protein.