Primary Ewing's sarcoma (ES)/peripheral primitive neuroectodermal tumor (pPNET) of the tongue in a child: A case report.

Ewing's sarcoma (ES) and primitive neuroectodermal tumor (PNET) are high grade malignant small round cell tumors presenting in both skeletal and extraskeletal anatomic locations. Actually, they are the same entity showing varying degrees of neuroectodermal differentiation. Very few cases of peripheral PNET (pPNET) of the tongue was reported in medical literature. Here, we first report a case of primary extraskeletal ES/pPNET in the tongue of a 9-years old girl. The result of immunohistochemical analysis showed the membranous positive for CD99 and Vimentin. The girl underwent radical surgical treatment and received six cycles of OPEC regimen adjuvantchemotherapy without radiotherapy, and now she is remaining tumor-free survival. The individual comprehensive therapy shows a good curative effect.