|H & E||H & E||H & E||H & E||H & E||H & E||Myogenin|
Microscopic examination showed sheets of blue cells that are present between residual fragments of striated muscle and adipose tissue, with collagenous fibrovascular trabeculae surrounding collections of tumor cells. The tumor cells have oval chromatic nuclei with prominent nucleoli. Occasional tumor cells exhibit a prominent component of pink cytoplasm. Mitotic figures are readily identified. Myogenin immunohistochemistry shows strong nuclear staining in most cells.