Neurofilaments in adrenal and extra-adrenal pheochromocytoma. Demonstration using immunofluorescence microscopy

Three cases of pheochromocytomas (two adrenal and one retroperitoneal) were studied immunohistologically, using specific antibodies against different types of intermediate filaments. A strong positive reaction was seen in immunofluorescence microscopy with antineurofilament antibodies, while no staining of tumor cells was observed with antikeratin, antivimentin, or antidesmin antibodies. The results are in accordance with the neuroepithelial derivation of adrenal medulla and paraganglia and suggest that antineurofilament antibodies can be used as an adjunct aid in identifying pheochromocytomas.