Embryonal Rhabdomyosarcoma : Cross-striations

Comments:
Cross-striations are usually seen in better-differentiated embryonal rhabdomyosarcomas (RMS) with a prominent spindle cell component. Generally, there is admixture of small undifferentiated cells and better-differentiated elongated or fusiform rhabdomyoblasts.

The rhabdomyoblasts range from delicate spindle-shaped cells to large strap, ribbon, tadpole, or racket-shaped cells with deeply eosinophilic cytoplasm. The nuclei are large, round, and vesicular with a prominent nucleolus. The cross-striations in neoplastic cells are arranged irregularly and traverse only part of the cell in contrast to those seen in entrapped normal muscle cells.