Peripheral primitive neuroectodermal tumor of the mandible: a case report and literature review / 口腔疾病防治

Objective@# 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.@* Methods@# 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. @* Results @#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.@*Conclusion@# pPNETs have a high degree of malignancy, easy recurrence and poor prognosis, so early diagnosis and treatment are extremely important.

Primary primitive neuroectodermal tumor of the kidney

Renal primitive neuroectodermal tumor (PNET) is a rare entity. It should be differentiated from other primary renal malignancies. The differentiation of the malignant small round cell tumors may be challenging; however, it is essential for better management of the patient. We report a 45-year-old male having complaints of pain in the abdomen, hematuria, and mass in the abdomen for 6 months. Abdominal and pelvic sonography finding showed cystic-solid, right renal mass suggestive of malignancy. On histopathology diagnosed as malignant small round blue cell tumor suggestive of primitive neuroectodermal tumor. On immunohistochemistry, CD99 positivity confirmed the diagnosis of primary PNET of the kidney. We are presenting this case for its rarity, clinical presentation, and pathological findings.

Primary peripheral primitive neuroectodermal tumor of the ovary with an epithelial cyst : A case report and review of literature.

Peripheral primitive neuroectodermal tumor (pPNET) has some histologic resemblance to a classic central primitive neuroectodermal tumor (cPNET), however it is distinctively different from cPNET by its CD99 immunoreactivity, characteristic chromosomal translocation, t(11;22)(q24:q12) and EWS/FLI-1 chimeric mRNA. Peripheral PNETs have a predilection for soft tissues rather than for viscera. Only 15 cases of primary ovarian PNET have been reported, and only one case was proven to be pPNET. Ovarian PNET is an aggressive tumor. We report a case of a 40-year-old Thai woman with a Stage IIIb right ovarian PNET is an aggressive tumor. Despite debulking operation and vigorous adjuvant chemotherapy, the patient died of disease 6 months later. Grossly, the tumor was solid and cystic. Microscopically, the former displayed unique features mimicking cPNET, but the pPNET phenotype was validated by CD99 staining. The solid portion also contained mucin-producing gland-like structures, previously described as ependymal diffentiation. In the cystic portion, the histology demonstrated epithelial linning tissue resembling cystadenoma of borderline malignancy of the ovary. It is generally accepted that both cPNET and pPNETs can have polyphenotypic differentiation. PNETs can be originated from either totipotential germ cells, neural crest remnant or mullerian-derived cells.

The Combined Therapy of Peripheral Primitive Neuroectodermal Tumor in Childhood / 대한소아혈액종양학회지

PURPOSE: A review of the literature for patients with peripheral primitive neuroectodermal tumor (PPNET; peripheral neuroepithelioma) suggests that the outcome is usually poor. We performed a retrospective study to emphasize the need for triple combined therapy of PPNET. METHODS: The clinical data of 10 patients (M:F=1:1, aged 1 8/12~14 3/12 years) with PPNET seen at Seoul National University Children's Hospital from Jan. 1991 to Jun. 1998 were reviewed. RESULTS: The primary sites were head and neck, chest, limbs, and retroperitoneal area in order of frequency. A palpable mass was the major symptom. The median duration of symptoms before diagnosis was 3 months. Metastatic disease at diagnosis was found in 3 patients, 2 of them were multiple. All of the patients had combined modality treatment with surgery, chemotherapy and radiation therapy. The 3-year relapse-free survival rate was 64%, and the overall 5-year survival rate was 66%. CONCLUSION: Best results were obtained with combined therapy with combination chemotherapy, extensive surgery and local radiation therapy.