Clinical,imaging and pathological features of 16 cases with oral and maxillofacial Ewing's sarcoma/PNET tumors

Objective To clarify the clinical,Imaging and morphological features of oral and maxillofacial Ewing's sarcoma/PNET(primitive neuroectodermal tumors),to further improve the knowledge and diagnostic accuracy for it.Methods 16 cases of oral and maxillofacial Ewing's sarcoma/PNET were observed and analyzed for the clinical symptom,Imaging Features,gross figure,histopathology,immuno-histochemistry(IHC),treatment and prognosis.Results In 16 cases,there were 13 PNET,3 Ewing's sarcoma.Age of onset ranged from 5 months to 48 years old,with an average of 20.9 years,patients in 14 cases are male,which amounts to 87.5% of all.CT,MRI showed the invasive growth pattern,morphological features of HE staining showed small round cell tumor,All of the 16 cases were positive for CD99,NSE expression.Follow-up was available for 15 cases:12 cases died of their disease at 3 to 17 months after surgery,the remaining 3 patients were followed up for 6~10 months so far.Conclusions Oral and maxillofacial Ewing's sarcoma/PNET is a rare highly malignant small round cell tumor,With highly malignant,easy to relapse and poor prognosis features.Imaging may suggest the malignant nature,Ultimately the tumor type were decided by features of HE and IHC.Treatment of surgical excision combined with postoperative radiotherapy and chemotherapy.