The tumor was resected, and immunohistochemistry revealed the tumor to be positive for smooth muscle actin and collagen type IV, and negative for synaptophysin, chromogranin A, laminin, S-100, cluster of differentiation (CD)34, CD31, CD99, cytokeratin (AE1/AE3), desmin and epithelial membrane antigen. This evidence concerns the gene CD99 and neoplasm.