“…[ 7 ] Immunohistochemistry is required to differentially diagnose it from other small round cell neoplasms, namely lymphoma (CD20, CD3 positive) and Ewing's sarcoma/primitive neuroectodermal tumour (CD99 positive) as RMS is negative for these markers. [ 9 ] The RMS tumour cells express Desmin, Myogenin, CD56, muscle-specific actin, Myoglobin, Vimentin, and MyoD1. The demonstration of foetal haemoglobin in tumour tissue by immunoperoxidase staining has been shown to be reliably accurate in identifying RMS.…”