Peripheral primitive neuroectodermal tumor of the mandible: a case report and literature review

To explore the clinical, imaging and pathological characteristics of mandibular peripheral primitive neuroectodermal tumors, and to review relevant literature to improve the understanding and diagnosis of pPNET in mandible.

The clinical and imaging features, pathological examination, treatment and prognosis of a case of mandibular pPNET diagnosed and treated at the First Affiliated Hospital of Xinjiang Medical University were observed, and analyzed a literature review.

The patient′s clinical manifestations were an enlarged mass of the mandible, hard texture, unclear borders, involving loose teeth, and numbness of the lower lip; CT and MRI showed osteolytic and aggressive growth patterns. The mandibular tumor was resected and the mandibular partial truncated resection was performed on the titanium plate. Postoperative pathological sections showed small round cell tumors under HE staining and Vimentin and Fli-1 were positive, and the pathological diagnosis was pPNET. The patient did not undergo chemoradiotherapy after surgery and died of tumor recurrence after 9 months of follow-up. A review of the relevant literature revealed that pPNETs are a group of small round cell tumors, which are more common in children and adolescents. pPNETs have a high degree of malignancy, a short course of disease and fast metastasis. The main route of metastasis is through the blood circulation. Most patients die within 2 years, the 3-year survival rate is only 30%, and the 5-year survival rate is less than 10%. Imaging is generally nonspecific; therefore, pPNETs are easily misdiagnosed. The final tumor type is determined by pathological HE staining and immunohistochemical characteristics. Current treatment methods are mainly complete surgical resection combined with postoperative radiotherapy and chemotherapy, but it is critical to provide individualized treatment to patients when necessary.

pPNETs have a high degree of malignancy, easy recurrence and poor prognosis, so early diagnosis and treatment are extremely important.