1. Alveolar rhabdomyosarcoma, 4x2. Alveolar rhabdomyosarcoma, 4x3. Alveolar rhabdomyosarcoma, 4x4. Alveolar rhabdomyosarcoma, 10x5. Alveolar rhabdomyosarcoma, 10x6. Alveolar rhabdomyosarcoma, 20x7. Alveolar rhabdomyosarcoma, 20x8. Alveolar rhabdomyosarcoma, 20x9. Alveolar rhabdomyosarcoma, 40x10. MYF4, 10x11. Desmin, 10x12. S100, 10x13. CD99, 20x14. Ki-67, 10x15. MyoD1, 10x16. Rhabdomyosarcoma consisting almost entirely of differentiated rhabdomyoblasts, a feature encountered in recurrent tumors following therapy, 10x17. Rhabdomyosarcoma consisting almost entirely of differentiated rhabdomyoblasts, a feature encountered in recurrent tumors following therapy, 10x18. Rhabdomyosarcoma consisting almost entirely of differentiated rhabdomyoblasts, a feature encountered in recurrent tumors following therapy, 10x19. Rhabdomyosarcoma consisting almost entirely of differentiated rhabdomyoblasts, a feature encountered in recurrent tumors following therapy, 20x20. Rhabdomyosarcoma consisting almost entirely of differentiated rhabdomyoblasts, a feature encountered in recurrent tumors following therapy, 20x