Two Cases of Ewing Sarcoma/Primitive Neuroectodermal Tumor With Initial Presentation in the Mandible

Abstract

Ewing sarcoma and primitive neuroectodermal tumor (ES/PNET) represent opposite ends of a spectrum of malignant round-cell neoplasms that show variable degrees of neuroectodermal differentiation. Initial presentation of ES/PNET in the oral cavity is exceedingly rare, and involvement of the gnathic or craniofacial region occurs in approximately 1% to 2% of cases. We contribute 2 cases of ES/PNET presenting as enlarging mandibular radiolucencies from a 5-year-old boy and a 34-year-old man. Although ES/PNET may involve any site, it predominantly affects bone, representing the third most common primary malignancy of bone following osteosarcoma and chondrosarcoma.