Immunohistochemical characterization of a case of duodenal gangliocytic paraganglioma.

A case of duodenal gangliocytic paraganglioma (DGP) arising in the ampulla of Vater of an 84 year old male is reported. The present case shows the typical histological features with a mixture of epitheliold, ganglion-like and spindle cells. Immunohistochemically, the spindle cells were positive with antibodies to neuron specific enorse, S-100 protein and neurofilament (NF), but negative for anti-glial fibrillary acidic protein (GFAP), synaptophysin and myelin basic protein (MBP). Both anti-Leu-7 and -chromogranin A antibodies gave positive reactions with a fine granular pattern in the epithelioid cells. Most ganglion-like cells showed the cytoplasmic immunoreaction with GFAP and a few with NF and synaptophysin. In these three tumor components, no reactivity was detected in the antibodies to the neurohormonal peptides tested. The present data are fundamentally in keeping with those previously reported, but add the immunohistochemical positivity of ganglion-like cells for GFAP, suggesting different neuroglial differentiation.