Spindle Cell Rhabdomyosarcoma
Higher magnification of a spindle cell variant of embryonal rhabdomyosarcoma in the paratesticular region of a 6 y/o male. The spindled tumor cells with hyperchromatic nuclei are haphazardly arranged. Some cases show storiform growth pattern. Round cell areas or pleomorphic cells are not found. This case was positive for desmin (strongly +ve), muscle specific actin (focally +ve), and myogenin (moderate nuclear positivity). Following markers were negative: chromogranin, synaptophysin, and S-100 protein.