MRI Features of Intracranial Primitive Neuroectodermal Tumors in Adults:Comparing with Histopathological Findings

The MRI appearances of 7 adult patients with pathologically proven intracranial primitive neuroectodermal tumors (PNET) were retrospectively analyzed. The MRI features were compared with findings in pathology and surgery. In this group, the tumor masses were most commonly found in the semisphere of cerebrum and in the vermis of cerebellum. They were relatively large and 4 were in lobulated shape. All of them had well defined margins. MR images showed the tumors to be mildly or obviously hypointense on T 1 weighted images and hyperintense on T 2 weighted images. Most masses had heterogeneous appearances with some cystic and necrotic areas. Intratumoral haemorrhage and focal calcification were occasionally seen. Mostly, there was no or only mild surrounding edema. Marked inhomogeneous contrast enhancement on MRI was seen in 6 cases except one. Two patients with multiple intracranial metastases were revealed on MR images. In this series, there was good correlation between MRI features and findings in pathology and surgery. These results showed that certain MRI features might suggest the diagnosis of intracranial PNET in adults. MRI is an effective technique to detect these tumors and is helpful to treatment planning and follow up.

Peripheral primitive neuroectodermal tumors:a rare case report

We aimed to explore the diagnosis and treatment of peripheral primitive neuroectodermal tumors （pPNETs）. We retrospectively analyzed the diagnosis and treatment process of a patient who was diagnosed with pPNETs by pathology. This case was a man with soft masses arising from the left chest wall near the armpit and left supraclavicular of a 47-year-old man. The patient mainly presented with the masses which increasing gradually with obvious pain. Needle biopsy showed that they were both metastatic adenocaroinoma. Ultrasonography B revealed blood flow of these two low density placeholders can be seen in the signal, not oppression axillary and vein. Radical resection of the masses were performed. Histopathologic study and immunohistochemistry （IHC） confirmed the masses to be peripheral primitive neuroectodermal tumors, pPNETs is a rare malignant small round cell tumor. CT and MRI examination can estimate the resectability of the tumor; Ultrasound B can make sure its inside blood supply and the positional relationship between the mass and the surrounding vasculature. The diagnosis of pPNETs is based primarily on histopathologic study and IHC, especially those with the characteristics of the Homer-Wright and neuroendocrine markers. Radical resection of the tumor is the most effective therapeutic method. The effect of adjuvant chemo-radiation is worth affirmation. Autologous stem cell rescue besides adjuvant chemotherapy has been associated with prolonged survival.

Detection of EWS-FLI1 fusion transcripts in paraffin embedded tissues of peripheral primitive neuroectodermal tumors by nested reverse transcription polymerase chain reaction

Objective: To assess the feasibility and significance of detecting EWS-FLI1fusion transcripts in paraffin embedded tissues of peripheral primitive neuroectodermal tumors (PNETs) by nested reverse transcription polymerase chain reaction(RT-PCR). Methods: Twelve formalin-fixed and paraffin-embedded (FFPE) samples of PNET were retrieved from archive and consultation materials, together with eight cases of controlled tumor. EWS-FLI1 fusion transcripts were detected by nested RT-PCR. Home-keeping gene β-actin was used to detect the quality of mRNA. Results: β-actin mRNA was detected in 9 of the 12 tumor cases. EWS-FLI1 fusion transcripts were detected in 6 cases, among which 4 had a “type 1” fusion transcript and 2 had a “type 2” fusion transcript. None of the controlled tumor was detected the fusion gene. Conclusion: RT-PCR is a feasible method for the detection of EWS-FLI1 fusion transcripts in FFPE tissues in PNET and the result is meaningful in differential diagnosis and prognostic evaluation.

Primitive neuroectodermal tumors of the abdominal wall and vulva in children: Report of two cases and review of the literature

BACKGROUND Primitive neuroectodermal tumors are rare,highly malignant small round cell tumors belonging to the Ewing sarcoma family.The purpose of this article is to present clinical manifestation,histology,treatment,and prognosis of two primitive neuroectodermal tumors(PNETs)in extremely rare anatomic locations,the abdominal wall and vulva.CASE SUMMARY Case 1 was a 66-month-old girl with lesions on the abdominal wall;tumor size was about 3.4 cm×6.1 cm×2 cm.The patient underwent radical resection of the tumor.After the operation,an alternating vincristine,doxorubicin,and cyclophosphamide/ifosfamide and etoposide(IE)regimen was given for eight cycles,and the patient survived for 66 mo without progression.Case 2 was a 40-month-old girl,with a vulvar lesion;tumor size was about 3.3 cm×5 cm×2.5 cm.The tumor was partially resected by surgery.The family left treatment after two cycles of vincristine,pirarubicin,and cyclophosphamide/IE chemotherapy,and the patient died at home six months after surgery.CONCLUSION PNET is a rare,fast-growing,highly malignant tumor that requires histologic and molecular analyses for exact diagnosis,and multimodal treatment is required to achieve a good prognosis.

Primary primitive neuroectodermal tumor in the pericardium-a focus on imaging findings:A case report

BACKGROUND Primitive neuroectodermal tumors(PNETs)are rare,sporadic malignant tumors of the peripheral nervous system,bone,or soft tissues.However,to the best of our knowledge,only three cases of PNET in the pericardium have been reported in the English literature,and their magnetic resonance imaging findings have not previously been described.CASE SUMMARY A 3-year-old boy was hospitalized with a 1-wk history of recurrent vomiting and weakness.Detailed history-taking revealed no evidence of heart disease.Computed tomography demonstrated a soft tissue mass in the left pericardial cavity with heterogeneous contrast enhancement.The border between the mass and the heart was poorly defined.Thoracotomy revealed a mass invading the left ventricle,with a high risk of bleeding.The mass was considered inoperable.A biopsy was performed,and the histological and immunohistochemical findings confirmed the diagnosis of primary PNET of the pericardium.The patient received four cycles of standard chemotherapy.Chest magnetic resonance imaging 3 mo after the initiation of chemotherapy revealed that the tumor in the pericardium still existed,but its volume had slightly decreased.The patient was lost to follow-up,and the final outcome was therefore unknown.CONCLUSION Medical imaging plays an important role in defining the pericardial origin of PNET and understanding its characteristics.Magnetic resonance imaging can provide more information on the tumor than computed tomography and may thus aid therapeutic planning.

Peripheral primitive neuroectodermal tumor of the posterior mediastinum: A case report

Peripheral primitive neuroectodermal tumor(pPNET) is an extremely rare disease entity of malignant tumors belonging to the Ewing sarcoma family that usually occurs in children and adolescents. We describe a 41-year-old female who presented with right upper abdominal pain. Surgical resection and biopsy revealed small round-cell tumor. Combined with immunohistochemical analysis, pPNET was diagnosed. No evidence of recurrence was noted at 18 months postoperatively. Even thought pPNET is a highly malignant tumor, Wide tumor-free resection and multi-agent chemotherapy can also obtain good clinical outcomes.

Diagnosis and treatment of spinal primitive neuroectodermal tumor

Objective To sum up the clinical experience in diagnosis and treatment of spinal primitive neuroectodermal tumor(PNET). Methods Thirteen patients with spinal PNET were included in the study from 1999 to 2009.There were 8 males and 5

Clinical pathologic analysis of urologic primary primitive neuroectodermal tumor

Objective To explore clinico-pathological features,immunophenotype,treatment and prognosis of urologic primary primitive neuroectodermal tumor ( PNET) . Methods The clinical data of 3 patients with urologic PNET were analyzed retrospectively. All patients were male,aged 29,32 and 75 years respectively.

Peripheral primitive neuroectodermal tumor of the kidney presenting with pulmonary tumor embolism: A case report

Peripheral primitive neuroectodermal tumor(PNET) of the kidney is a rare, aggressive tumor known for its recurrence and metastatic potential. Despite the frequency of venous extension to the renal veins and inferior vena cava, pulmonary tumor embolism at the initial presentation is not common. We report a case of 22-year-old female with PNET of the kidney who presented with tumor embolism in the inferior vena cava(IVC) and bilateral pulmonary artery. The patient underwent surgical resection and histopathological analysis confirmed the presence of tumor within the IVC and pulmonary arteries. The patient received adjuvant chemotherapy and is currently doing well on follow-up.

Huge peripheral primitive neuroectodermal tumor of the small bowel mesentery at nonage:A case report and review of the literature

Extraskeletal Ewing's sarcoma/peripheral primitive neuroectodermal tumor(E-EWS/pP NET) is a rare aggressive malignant small round cell tumor. In this report, we present the case of a 15-year-old boy who suffered from acute abdominal pain accompanied by hematemesis and melena, and was eventually diagnosed with E-EWS/p PNET. To date, there have been only five reported cases of E-EWS/pP NET of the small bowel including the patient in this report. To the best of our knowledge, this is the first documentation of a pP NET of the small bowel mesentery at nonage. All these have made this report rare and significant.

Huge primitive neuroectodermal tumor of the pancreas:Report of a case and review of the literature

Primitive neuroectodermal tumor (PNET) of the pancreas is an extremely rare tumor that usually occurs in children or young adults. We report a case of a 33-year-old male patient with an 18 cm × 18 cm × 16 cm mass arising from the pancreatic body and tail with a one- day history of abdominal pain. Initial CT scan showed no signs of metastatic tumor spread. The tumor caused intrabdominal bleeding and the patient underwent primary tumor resection including partial gastrectomy, left pancreatic resection and splenectomy. Diagnosis of PNET was confi rmed by histology, immunohistochemistry and FISH analysis. All neoplastic cells were stained positive for MIC2-protein (CD99). Approximately one month after surgery, several liver metastases were observed and the patient underwent chemotherapy according to the Euro- Ewing protocol. Subsequent relaparotomy excluded any residual hepatic or extrahepatic abdominal metastases. Although PNET in the pancreas is an extremely rare entity, it should be considered in the diffential diagnosis of pancreatic masses, especially in young patients. This alarming case particularly illustrates that PNET in the pancreas although in an advanced stage can present with only a short history of mild symptoms.

Long-term survival of a patient with a large adrenal primitive neuroectodermal tumor: A case report

BACKGROUND Adrenal primitive neuroectodermal tumor(PNET) is an extremely rare malignant tumor with poor prognosis and of neural crest origin. Herein, we report a case of adrenal PNET and summarized its clinical and pathological characteristics on the basis of 16 patients reported recently.CASE SUMMARY A female patient aged 25 years presented with right lumbago for 12 mo, and preoperative computed tomography showed a huge right adrenal mass. She received tumorectomy, and post-operative pathological examination showed adrenal PNET. After surgery, she underwent adjuvant chemotherapy and was followed up 31 mo after surgery. She received brachytherapy for right paracolic and hepatic metastases. She was alive and followed up for 60 mo. In available studies, only 57.14%(4/7) and 44.44%(4/9) were positive for the expression of neuron-specific enolase and synaptophysin, respectively, although CD99 expression was found in all the patients(100%; 10/10).CONCLUSION It is concluded that adrenal PNET is very rare and highly malignant, and histology is a golden standard in its diagnosis. Surgery and adjuvant therapy is the main treatment.

Total pelvic exenteration and a new model of diversion for giant primitive neuroectodermal tumor of prostate: A case report and review of the literature

The present study reports a rare primitive neuroectodermal tumor (PNET) of prostate.A 27-year-old male was admitted to Harbin Medical University Cancer Hospital (Harbin,China) for dysuria and dyschezia. Magnetic resonance imaging (MRI) revealed a large mass thatmay involve the bladder and rectum next to the prostate. Histopathological analysis of biopsyof prostate indicated mesenchymal origin tumor, and immunohistochemistric stainingconfirmed diagnosis of PNET of prostate. En bloc total pelvic exenteration and double barrelsigmoidostomy were performed. Double stomas in the skin incision were used for fecal andurinary diversion, respectively. Short-term outcome is satisfactory, while long-term efficacyremains to be poor. Clinical features of PNET of prostate should be paid much more attentionand radical surgery and adjuvant chemotherapy should be recommended.

Molecular detection of EWS-Ets fusion transcripts and their clinicopathologic significance in Ewing’s sarcoma/peripheral primitive neuroectodermal tumor

Background Ewing＇s sarcoma/peripheral primitive neuroectodermal tumor （ES/pPNET） is often difficuh to distinguish from other small round cell tumors. The EWS-Ets gene fusions that result from chromosomal translocations in this tumor provide potential molecular diagnostic markers. To apply these molecular markers to commonly available archival materials, we evaluated the feasibility of detecting EWS-Ets including EWS-Flil and EWS-ERG fusion transcripts in paraffin-embedded tissues and its diagnostic value for detecting ES/pPNET. Methods Thirteen paraffin-embedded samples of ES/pPNETs were retrieved from archives. Thirteen cases of other tumors with small round cell features （including rhabdomyosarcoma, neuroblastoma, lymphoma, small ceil carcinoma, and desmoplastic small round cell tumor ） were used as negative controls. β-actin and β2- microglobulin were used as internal controls. A nested reverse transcriptase-polymerase chain reaction （RT- PCR）-based assay was performed to detect the EWS-Flil and EWS-ERG fusion transcripts. Results β-aetin and β2-mieroglobulin were detected in 10/13 and 13/13 ES/pPNETs, respectively. EWS- Flil fusion transcripts were detected in 11 of 13 （85%） ES/pPNETs. Three chimeric transcripts, all EWS-Flil, were detected in ES/pPNET samples. Among 11 EWS-Flil-positive cases, 7 eases had a type Ⅰ fusion transcript involving fusion of EWS exon 7 with Flil exon 6, 2 eases had a type Ⅱ fusion transcript involving EWS exon 7 with Flil exon 5, and 2 eases expressed fusion transcripts involving EWS exon 7 and Flil exon 8. Type Ⅰ EWS- Flil fusion predominated over other types. Fusion types could not be distinguished in the remaining 2 eases. Thirteen negative controls did not show detectable chimeric messages. There was a significant relationship between EWS-Flil fusion transcripts and CD99 expression. Conclusions Molecular detection of EWS-Flil fusion transcripts in formalin-fixed paraffin-embedded material by nested RT-PCR is feasible and is useful for the diagnosis and differential diagnosis of ES/pPNETs.

Primitive neuroectodermal tumor of uterus——A rare entity

Primitive neuroectodermal tumor (PNET) of uterus is the rare of the rarest among the tumors of female genital tract. We herein reported a 32 years old female operated for lower abdominal lump,which was diagnosed,as PNET later confirmed by immunohistochemistry (IHC). She was lost to follow-up and presented 10 months later with recurrence. She was treated with cyclical combination chemotherapy followed by definitive surgery and is in complete remission at present.

Imaging manifestations of renal primary neuroectodermal tumors

Primitive neuroectodermal tumors （PNETs） are a rare group of small round cell tumors belonging to the same family of tumors. According the primary location, the neoplasms were divided into central and peripheral PNET （pPNET）. Renal PNET was extremely rare. We report two cases of renal PNET conformed operationally and pathologically.

Primitive Neuroectodermal Tumor as the Second Malignant Neoplasm in a Long-Term Survivor Child of Acute Lymphoblastic Leukemia: A Case Report

Acute lymphoblastic leukemia(ALL)is a common pediatric cancer.The second malignant neoplasms(SMNs)in long-term survivors of pediatric ALL are relatively rare.Herein we report a 10-year-old girl who was diagnosed as primitive neuroectodermal tumor(PNET)5 years after the initial diagnosis of ALL with radiotherapy・free treatment.PNET is an exceedingly rare neoplasm in SMNs of survivors of childhood ALL.It is predisposed to be misdiagnosed and the pathogenesis is unclear.The outcome is poor.Long-term follow-up is necessary for the survival children of ALL.

Primitive neuroectodermal tumor of the prostate in a 58-year-old man:A case report

BACKGROUND Primitive neuroectodermal tumor(PNET),especially located in the prostate,is a rare tumor that mainly occurs in young men.Bladder or rectum invasion and distant metastasis are strongly associated with a poor prognosis.Combination therapy,including radical surgery,adjuvant chemotherapy,and radiotherapy,is available.We present a case of prostatic PNET and a review of 17 cases identified in the literature.CASE SUMMARY A 58-year-old man was admitted complaining of dysuria for 2 years.Computed tomography and magnetic resonance imaging showed a large cystic-solid mass in the pelvic cavity compressing the surrounding bladder and rectum.The mass was iso-to hyperintense on T1-weighted imaging(WI)and heterogeneously hyperintense on T2WI.Cystic degeneration and necrosis were seen in the tumor,and solid tissues within the mass enhanced on contrast-enhanced scan.The patient underwent robot-assisted laparoscopic pelvic tumor resection.Histologically,the presence of many small round cells that were positive for expression of CD99,vimentin,and synaptophysin established the diagnosis of PNET in the prostate after surgery.The patient underwent adjuvant chemotherapy.During 34 mo of follow-up,the patient had no signs or symptoms of recurrence or residual disease.CONCLUSION We present the case of the oldest prostatic PNET patient,who has a good prognosis.This illustrates how older men with prostatic PNET may also benefit from the combination therapy,like younger adults,and achieve a long-term survival.As always,PNET should be considered in the differential diagnosis of aggressive prostatic tumors in young men.

Ewing sarcoma/primitive neuroectodermal tumor of the ureter:A case report and literature review

Ewing sarcoma/primary neuroectodermal tumors are rare,invasive,and small round blue cell tumors.There are few reports of its occurrence in the urinary system.Here,we present the first middle-aged female patient whose Ewing sarcoma primary site was in the ureter.The main clinical manifestation was intermittent hematuria.She was in good health after complete surgical resection and adjuvant radiotherapy.To date,there has been no recurrence or metastasis.Accurate early diagnosis and appropriate treatment can help prolong survival.18F-fluorodeoxyglucose positron emission tomography/computed tomography is expected to be an effective means of evaluating treatment effects and detecting metastasis and recurrence.In this article,besides introducing a case of Ewing sarcoma/primitive neuroectodermal tumor of the ureter,we review the literature to discuss the current status of diagnosis and treatment.

Ewings Sarcoma-Primitive Neuroectodermal Tumour-Rare Extraosseous Presentation

Introduction: Ewings sarcoma is uncommon in extra osseous locations. They belong to Ewings family of tumours and the primitive neuroectodermal tumour is often diagnosed based on immuno histochemistry and molecular genetic studies. Discussion: A 50-year-old gentleman presented with complaints of a swelling in the right thigh. With a diagnosis of soft tissue sarcoma, the patient underwent a wide local excision of the tumour. We review literature of the small round blue cell tumour. Conclusion: Extraosseous Ewings sarcoma presenting as a thigh swelling is uncommon. The sarcoma was vimentin positive and CD99 membrane positivity.