Kit expression in spindle cell rhabdomyosarcoma can possibly create a different approach for its tumorigenesis and therapy

The present study demonstrated a very limited expression of CD117 in pediatric embryonal RMS other than in the spindle cell variant. This finding suggested that the stem cell factor/c-kit pathway may be implicated in the tumorigenesis of spindle cell RMSs. Therefore, the mutation of c-kit gene must be prospectively examined in larger series of RMSs. If it can be verified that tissue expression of CD117 reflects the mutation of c-kit gene, IM can be considered a targeted therapy for CD117-expressing RMSs, particularly the spindle cell variant.