The tumor cells were markedly and diffusely positive for vimentin, alpha-inhibin (Fig. 3a), Melan-A (Fig. 3b), synaptophysin (Fig. 3c), NSE and CD56, and focally positive for pan-cytokeratin (AE1/AE3), but negative for PAX8, S100 and chromogranin A. The sustentacular pattern of S100 staining, typical in paraganglioma, was not observed in this case. This evidence concerns the gene ENO2 and neoplasm.