Comments: Expression of CD99 (013; HBA71; MIC2) - cell membrane protein - is consistently seen in ES/PNET; however it is not specific and may also be seen in embryonal rhabdomyosarcoma, other sarcomas, and lymphoblastic lymphoma. Image courtesy of Dr. Jean-Christophe Fournet, Paris, France; humpath.comreturn to Ewing Sarcoma/PNET
