Alveolar Rhabdomyosarcoma - Solid pattern
Solid variant of alveolar rhabdomyosarcoma (ARMS) lacks the alveolar pattern. It is composed of closely packed solid sheets of tumor cells that have yet to lose cellular cohesion for forming alveolar spaces. There may be areas with a hint of incipient alveolar pattern in the form of delicate fibrous septa surrounding groups of tumor cells. Solid areas are often present at the periphery of an otherwise typical alveolar RMS.