Intraspinal primitive neuroectodermal tumor arising from the sacral spinal nerve root

Adult Primary Spinal Epidural Extraosseous Ewing's Sarcoma: A Case Report and Review of the Literature

Background. Extraosseous Ewing's sarcoma in the spinal epidural space is a rare malignancy, especially in adults. Case Presentation. A 40-year-old male presented with back pain and urinary hesitancy. MRI revealed a thoracic extradural mass with no osseous involvement. He underwent surgery for gross total resection of the mass, which was diagnosed as Ewing's sarcoma. He was subsequently treated with chemoradiotherapy. He remains disease-free 1 year after surgery. Review of the literature indicated only 45 previously reported cases of spinal epidural extraosseous Ewing's sarcoma in adults. Conclusions. Extraosseous Ewing's sarcoma in the spinal epidural space is a rare clinical entity that should be included in the differential for spinal epidural masses. Its treatment is multidisciplinary but frequently requires surgical intervention due to compressive neurologic symptoms. Gross total resection appears to correlate with improved outcomes.

Primary primitive neuroectodermal tumor within the spinal epidural space: report of a case and review of the literature

Primary intraspinal primitive neuroectodermal tumors (PNETs) are rare tumors and a have poor prognosis. In reviews of the literature, it is seen that primary intraspinal PNETs may arise at all levels of the spine and may be intramedullary, intradural-extramedullary, or epidural. Spinal epidural location of PNET is extremely rare and out of 22 cases of primary spinal PNETs reported to date, only two were epidural. Tumors within the epidural space of the spinal canal are most often metastatic neoplasms from different primary sites. Here we report a case of primary extradural PNET located in the thoracic spine in a 16-year-old boy and review the relevant literature.

Primary spinal primitive neuroectodermal tumour: report of two cases mimicking neurofibroma and review of the literature

Primary spinal primitive neuroectodermal tumours (PNETs) are a rare entity. Most of them occur in children and young adults. To date, 47 cases of primary spinal PNET have been reported in the literature. We present two cases of primary spinal PNET. In both cases, the tumours were thoracic extradural ones with intrathoracic extension through intervertebral foramina resembling neurofibroma. These tumours are highly aggressive with rapid growth as evidenced by the short history in both of our cases. Both cases underwent gross total removal of the intraspinal and thoracic components. Postoperatively, both patients underwent cranio-spinal radiotherapy. A review of the literature shows that the overall prognosis of PNETs of the spinal cord is very poor even with adequate surgery, radiotherapy and chemotherapy. One patient died after 4 months and the other one is still alive 8 months after surgery, radiotherapy and chemotherapy.

Review of spinal neuroectodermal tumor

Primary spinal primitive neuroectodermal tumors (PNETs) are rare tumors. Most of these tumors occur in children and young adults. To date, 47 cases of primary spinal PNET have been reported in the literature. These tumors are highly aggressive with rapid growth. Review of the literature shows that the overall prognosis of PNETs of spinal cord is very poor even with adequate surgery, radiotherapy and chemotherapy. All the cases reported to date are reviewed in terms of surgical treatment, adjuvant therapy and outcome and the experience with two of these cases are described. Both cases were thoracic extradural ones with intrathoracic extension through intervertebral foramina resembling neurofibroma. Both cases underwent gross total removal of intraspinal and thoracic component. Post-operatively both underwent cranio-spinal radiotherapy. One patient died after a post-operative period of 4 months and the other one is still alive 8 months after surgery, radiotherapy and chemotherapy.

Primary spinal extradural Ewing's sarcoma (primitive neuroectodermal tumor): Report of a case and meta-analysis of the reported cases in the literature

Background:

Primary spinal primitive neuroectodermal tumors (PNET) and/or spinal extraskeletal Ewing's sarcoma family tumors (ESET) are rare lesions appearing in the spinal extradural space. One hundred forty-one primary spinal PNETs, including 29 intramedullary lesions, have been reported in the literature. Encountering a case of primary epidural EES/peripheral PNET (pPNET) in sacral level, which is the fifth one occurring at this level in the literature, we have tried to conduct a meta-analysis of the reported cases.

Case Description:

A 44-year-old lady with epidural EES/pPNET is reported here. She was once operated for L5/S1 herniated disc, which did not ameliorate her symptoms. The clinical, imaging, surgical, and histopathologic characteristics of our case are presented and wide search of the literature is also done. All the reports were level 3 or less evidences and most of the series had missing parts. 106 cases of primary intraspinal (extradural/extramedullary-intradural) EES/pPNET and 29 cases of primary intramedullary PNET (CNS-PNET) have been reported in the literature. The most common clinical presentation in both entities was muscle weakness proportionate to the tumor location. Distant metastasis occurred in 38 of 99 (38%) cases of primary intraspinal EES/pPNET, while the rate of metastasis was 48% in patients with PNETs occurring in the intramedullary region (P > 0.05). One-year survival rate of the patients who underwent chemo-radiation after total or subtotal resection was better than those who did not receive chemotherapy or radiotherapy, or did not have total or subtotal resection. However, this difference was not repeated in 2-year survival rate in any of the tumor groups.

Conclusion:

It seems that total or subtotal removal of the tumor and adjuvant chemo- and radiation therapy can improve the outcome in these patients.

Magnetic resonance imaging characteristics of primary intraspinal peripheral primitive neuroectodermal tumour

PURPOSE

The purpose of our study was to describe the salient magnetic resonance imaging (MRI) findings in primary intraspinal peripheral primitive neuroectodermal tumour (PNET).

METHODS

A retrospective review of the clinical and MRI images of 7 pathologically proven cases of intraspinal peripheral PNETs was performed. The various parameters, such as vertebral level of involvement; tumour location, size, focality, and margin; signal intensity of the lesion; the presence of hemorrhage or calcification; any signal voids; assessment of the adjacent cord for cord compression; cord dilatation; the presence of paraspinal tissue mass; or vertebral or other bony changes, were analysed.

RESULTS

All 7 patients had lesions in the thoracolumbar region. Three patients had extradural lesions, 4 had intradural extramedullary lesions, and none had intramedullary lesions. Six lesions were well circumscribed. Only 1 patient had multifocal involvement. All lesions were of hypointense or isointense signal on T1-weighted imaging, whereas all but one were hyperintense on T2-weighted imaging. Lesions enhanced heterogeneously except 1 intradural extramedullary lesion, which enhanced homogeneously. A paraspinal mass was noticed in 2 patients. Vertebral collapse was present in 1 patients.

CONCLUSION

Intraspinal peripheral PNETs are rare spinal tumours. Although imaging characteristics are not specific, a focal circumscribed lesion in a young individual at the intramedullary, extramedullary intradural, or extradural spinal location that shows hypointense and hyperintense signal on T1- and T2-weighted images, respectively, requires PNET to be considered in the differentials.

Intraspinal Ewing's sarcoma/primitive neuroectodermal tumors

Intraspinal Ewing's sarcoma (ES) and primitive neuroectodermal tumors (PNET) are very rare, and the characteristics and prognoses of the disease remain unclear. We present an illustrative patient with an intradural, extramedullary PNET arising within the cervical spinal canal, with clinical and radiological manifestations of leptomeningeal spread, and review the reports of a further 77 patients with intraspinal ES/PNET. Cox regression analyses showed that tumor location (extradural, intradural) (p=0.002, RR=4.217, 95% confidence interval [CI] 1.668-10.664) and spinal segment location (cervical, thoracic, lumbar, or sacral) (p=0.017, RR=2.040, 95% CI 1.133-3.673) were independent factors in the prognosis of intraspinal ES/PNET. We concluded that a peripheral PNET may originate within the spinal canal and exhibit leptomeningeal spread similar to that seen in central PNET, and that a patient with an intradural ES/PNET high in the spinal canal is more likely to have a poor prognosis.

Primary primitive neuroectodermal tumor of the conus medullaris in an elderly patient: a case report and review of the literature

Primary spinal primitive neuroectodermal tumors (PNETs) are very rare conditions. Most of these tumors occur in children and young adults. A 63-year-old man with a primary spinal PNET in the conus medullaris from the L1 to L2 level is presented in this report. The optimal treatment of primary spinal PNETs is yet unknown. Surgical resection, radiation therapy, and chemotherapy have been advocated for the treatment of spinal PNET based on PNETs at other sites. However, the outcome is very poor. There are a few reports of cases with long-term survival and no recurrence. In these patients, en bloc resections were performed.

Primitive neuroectodermal tumors of the spine: a comprehensive review with illustrative clinical cases

Primary spinal primitive neuroectodermal tumors (PNETs) are uncommon malignancies that are increasingly reported in the literature. Spinal PNETs, like their cranial counterparts, are aggressive tumors and patients with these tumors typically have short survival times despite maximal surgery, chemotherapy, and radiation. Because no standard management guidelines exist for treating these tumors, a multitude of therapeutic strategies have been employed with varying success. In this study the authors perform a comprehensive review of the literature on primary spinal PNETs and provide 2 new cases that highlight the salient features of their clinical management.

Peripheral Primitive Neuroectodermal Tumour (pPNET) in the cervical spine

Primary spinal primitive neuroectodermal tumours are rare. We present a 45-year-old man with a peripheral primitive neuroectodermal tumour arising in the cervical spine. We believe this to be the first report of this type of tumour in the cervical spine.

An unusual primitive neuroectodermal tumor in the thoracic epidural space

Primitive neuroectodermal tumor (PNET) is a generic term used to describe a group of histologically indistinguishable neoplasms, including cerebellar medulloblastomas, which are located at various sites in the central nervous system. Primary epidural PNETs are rare and few patients have been reported. We report a 15-year-old girl who presented with gradual onset, over 1 month, of upper back pain and bilateral lower leg weakness. A thoracic spine MRI showed a dumbbell-shaped epidural mass at T2-4 with right paraspinal and posterior mediastinal extension. Surgical resection of the epidural tumor for decompression was performed. The pathologic examination revealed a PNET. Primary spinal PNETs typically have a poor prognosis and optimal therapy has not yet been defined. Surgical resection, with the combination of chemo-radiotherapy or radiotherapy, leads to better outcomes. However, primary epidural PNETs may be classified as a subtype of spinal PNETs because they are free from intrathecal invasion. For these patients, surgery alone and surgery combined with radiotherapy or chemo-radiotherapy remain controversial. Our patient received surgery alone and, 1y ear later, has experienced no local recurrence within the epidural space but the mediastinal part of the tumor has enlarged.

Dumbbell-shaped peripheral primitive neuroectodermal tumor of the spine--case report and review of the literature

Primary spinal peripheral primitive neuroectodermal tumors (pPNETs) are extremely rare. Here, we present a case study of a 29-year-old male with a dumbbell-shaped pPNET at the T9-10 spine level, including details of his examination, surgical procedures applied, histological and genetic findings, and his subsequent treatment. We discuss the clinical course, the pathology and treatment for this disease, the surgical approach to thoracic dumbbell tumors and we review the literature. To our knowledge, this is the first report of a case of a dumbbell-shaped intradural and spinal peripheral PNET.

Sacral intraspinal extradural primitive neuroectodermal tumor

BACKGROUND CONTEXT

Intraspinal primitive neuroectodermal tumors (PNETs) are an exceedingly rare entity. A recent literature research revealed 28 cases reported. Only a few tumors in the literature were extradural in location, in the cervical and thoracic spine. The average survival after combination treatment including chemotherapy, radiation, and surgical resection is 20 months for the cases reported in the literature.

PURPOSE

We report a case of a patient with sciatica and cauda equine-like symptoms.

STUDY DESIGN

Case report.

METHODS

Urgent sacral decompression and resection of the tumor was performed with rapid pain relief for the patient.

RESULTS

Histology revealed a sacral extradural small blue-cell tumor, consistent with ES/PNET family tumors. An oncological workup revealed that the tumor presentation was metastatic with pulmonary and abdominal nodules. The patient underwent combination chemotherapy with vincristine, doxorubicin, and cyclophosphamide with mesna for 4 months.

CONCLUSIONS

The patient was without disease after excision, two courses of 4-month chemotherapy, and one course of 5-week radiation to the sacrum at 2 years.

Primary primitive neuroectodermal tumor of the lumbar extradural space

Primary spinal primitive neuroectodermal tumors (PNETs) of the extradural space are very rare; only 10 cases have been reported in the English language literature. The histopathological diagnosis of primary spinal PNETs has been discussed for many years. These tumors have a rapidly progressive course, and there is no current consensus on the optimal therapeutic approach for these patients. The authors present a case of primary PNET located in the lumbar extradural space in a 13-year-old girl and report the clinical, radiological, histopathological, and surgical findings. They compare their findings with those from the other 10 cases reported in the literature and review relevant literature.

Multiple primary primitive neuroectodermal tumours within the spinal epidural space with non-concurrent onset

A case of multiple primary primitive neuroectodermal tumours (PNETs), which occurred at different levels of the spinal epidural space successively over a period of 8 months, is reported. A 24-year-old male, presenting with rapidly progressive paralysis, hyperthesia and a posterior epidural mass extending from T8 to T10 revealed by magnetic resonance imaging (MRI), exhibited a good recovery after initial emergency surgery. Lower back pain, chest pain and paralysis were subsequently reported. Spinal MRI in month 7 revealed a mass extending from T12 to L1 and another mass extending from T4 to T5 was detected epidurally in month 8. Additional operations were performed and radiotherapy was given. Pathological findings were consistent with PNETs and symptoms improved with treatment, particularly following each surgical excision.

Primary peripheral primitive neuroectodermal tumors of the spinal cord: report of two cases and review of the literature

Primary intraspinal peripheral primitive neuroectodermal tumors (pPNETs) are extremely rare tumors with only seven reported cases in the literature. The histopathologic diagnosis of this tumor is complex and has led to a variety of treatment approaches. The distinction between central and peripheral type primary spinal cord PNETs has not always been made in the literature, leading to a paucity of data in this disease. We present here two young patients with primary intraspinal pPNET, their treatment and outcome. The first patient, a 27 year old male, presented with an intradural mass extending from L2 through L5, after multiple relapses, he is currently alive with disease after 72 months, the longest survival yet reported. The second patient, a 16 year old female, presented with an intradural mass at the cauda equina from L2 through L5, and is currently alive with responsive disease at 5 months after initial diagnosis. Here, we discuss the clinical course, the pathology and treatment for this disease and review the literature.

Primary spinal primitive neuroectodermal tumor: case series and review of the literature

Primary spinal primitive neuroectodermal tumor (PSPNET) is extremely rare and only 25 cases have been reported in the world literature so far. Three patients of 8, 9 and 18 years of age, who presented with variable grades of neurological deficit were diagnosed as having a dorsal intramedullary lesion, a holocord lesion and cervical extradural tumor with extraspinal extension, respectively, and were operated at our institute. The histopathology of all 3 children revealed PNET. The clinical course, image characteristics and outcome of the 3 children are described, and the relevant literature is reviewed. The following conclusions were drawn from the present study and review of the literature. PNET may manifest itself as a primary lesion of the spine unlike the more common drop metastases from an intracranial lesion. PSPNET may be intramedullary, intradural and extradural with variable extraspinal extension. PSPNET may present as holocord intramedullary lesion, an entity which has not been described earlier. These lesions have a short history, significant neurological deficits and rapid course of illness. PSPNET, though an established entity, did not find a place in the WHO 2000 classification of CNS tumors. Hence its status has to be defined.

Primary intramedullary primitive neuroectodermal tumor of the cervical spinal cord. Case report

Primary intramedullary primitive neuroectodermal tumors (PNETs) of the spinal cord are rare. Only six cases have previously been reported, all involving tumors in the thoracic or lumbar spine. The authors report the case of a 54-year-old woman who presented with quadriplegia and bladder and bowel dysfunction. The patient had suffered symptoms of neck pain for 1 month and left shoulder weakness for 10 days. Magnetic resonance imaging of the cervical spine revealed an intramedullary mass extending from C-2 to C-5 with an exophytic component in the adjacent left subarachnoid space. Multiple biopsy specimens were obtained, and a partial excision was performed. Histological examination revealed nodular growth and neuronal differentiation, with a striking resemblance to desmoplastic medulloblastoma. A positron emission tomography scan did not reveal uptake at any site. These findings confirmed the diagnosis of a primary intramedullary PNET. Postoperatively, the patient was given craniospinal radiotherapy with a radiation boost to the tumor bed.

Primary intramedullary primitive neuroectodermal tumor (PNET)--case report and review of the literature

Spinal primitive neuroectodermal tumors (PNET) are very rare tumors, and intramedullary localization is even less common. Indeed, amongst the 23 cases of the spinal PNET described in the literature, only eight cases had an intramedullary localization. Following the WHO 2000 classification, PNETs have been considered embryonal tumors composed of undifferentiated neuroepithelial cells with a capacity of differentiation into different cellular lines, such as astrocytic, ependymal, melanotic and muscular. They have been considered to arise from a neoplastic transformation of primitive neuroepithelial cells, thereby making their presence possible in any part of the central nervous system. The optimal treatment for these malignant tumors is not yet clear, although, over the years, radiotherapy has been considered the best treatment for spinal PNETs. The described case is that of a 38-year-old man with a primary intra-extramedullary PNET, treated by laminectomy, open biopsy and chemotherapy. The patient, 18 months after the onset of his symptomatology, died without cerebral tumor involvement.

Ewing's Sarcoma in the Spinal Nerve Root: A Case Report and Review of the Literature

Ewing's sarcoma (ES) is a highly malignant tumor composed of uniform small round cells. Recently, a single biologic entity, Ewing's sarcoma family of tumors (ESFT) has been accepted. The entity includes ES, extraskeletal Ewing's sarcoma (EES) and primitive neuroectodermal tumor (PNET). ESFT cells have immunoreactivity for CD99, an antigen determined by the MIC2 gene. Most ESFT has the (11;22) (q24;q12) translocation. The translocation results in the fusion of the EWS gene with the transcription factor gene FLI1 which has been considered a hallmark of ESFT. We present an extremely unusual case with ESFT in a spinal nerve root mimicking a neurogenic dumbbell tumor. A male aged 20 years noticed pain in his right buttock. Magnetic resonance imaging (MRI) revealed a mass in the right L5/S intervertebral foramen and the lesions in the sacrum. Surgery was performed with a presumptive diagnosis of a nerve sheath tumor. At surgery, the tumor was located in the right L5 nerve root sleeve. The sacral lesions were observed closely. At one month after surgery, radiologically multiple lesions were detected in the pelvic bones. Microscopically the lesions from the root and ilium were composed of small round cells immunoreactive for CD99. Reverse transcription-polymerase chain reaction detected transcripts resulting from the fusion of the EWS gene with FLI1 genes in the iliac lesion. Immunoreactivity for CD99 and detection of the EWS-FLI1 hybrid transcripts are important for the correct diagnosis of ESFT arising in an unusual location.

Primitive neuroectodermal tumours (PNETs) located in the spinal canal; the relevance of classification as central or peripheral PNET

Intraspinal location of central PNET (cPNET) is very rare. We present a case, critically review all publications of primary intraspinal cPNET occurrence and discuss tendencies in clinical presentation. In several previous attempts to summarise, authors often confused cPNET with peripheral PNET (pPNET). cPNET and pPNET are different entities with different immunohistochemical profiles and genetic backgrounds. Clinically, they are both aggressive tumours, but exhibit different characteristics in their local manifestation and metastatic spread. Survival rates are quite similar provided that treatment is applied according to the established protocols. Protocols in cPNET treatment differ from those for pPNET as regards the order of the treatment sub-modalities, specific chemotherapeutic regimen and intensity, radiation dose and its extent and consequently, the side effects. Therefore, failure to distinguish cPNET from pPNET leads to clinical guidance and treatment proposals based on false assumptions, which might effect outcomes. Often, distinguishing between cPNET and pPNET is easy, because they occur in different location. In the case of intraspinal tumour location, however, the differentiation is crucial because both primary cPNET and pPNET can occur intraspinally, even though this is rare. Nowadays, demonstrating the expression of MIC2 glycoprotein by immunocytochemical staining (CD99) showing the specific EWS-FLI1 chimeric gene presence in pPNET, offers an easy way of making a differential diagnosis between cPNET and pPNET.

Intracranial hypertension as an initial manifestation of spinal neuroectodermal tumor

A 19-year-old girl had headaches, blurred vision and vomiting for 2 weeks. Neurological examination revealed only bilateral papilloedema and left abducens palsy. Neuroimaging of the brain was normal. Cerebrospinal fluid study showed intracranial hypertension (IH), hypoglycorrhachia, hyperproteinorrhachia, and a negative cytology study. Eight months after the onset, paraparesis occurred. Spinal magnetic resonance imaging showed intramedullary masses at the cervical and thoracic cords with extensive seeding. Biopsy of the mass showed primitive neuroectodermal tumor (PNET). IH rarely occurs in patients with spinal cord neoplasms. Its incidence is low and the condition is always associated with signs of myelopathy. We report a patient whose initial manifestation of spinal PNET was IH only. Spinal tumor should be considered in IH patients whose intracranial examinations are negative.

First spinal axis segment irradiation with spot-scanning proton beam delivered in the treatment of a lumbar primitive neuroectodermal tumour. Case report and review of the literature

Primary intraspinal primitive neuroectodermal tumour (PNET) is a rare tumour entity. The optimal therapeutic management is unclear but, in general, this tumour is treated with surgery followed by radiotherapy and chemotherapy. Proton beam radiation therapy (PT) offers superior dose distributional qualities compared with X- or gamma rays, as the dose deposition occurs in a modulated narrow zone called the Bragg peak. As a result, organs at risk are optimally speared. Here, we present a patient treated with the first spinal axis segment irradiation using spot-scanning PT with a single field, combined with conventional cranio-spinal axis radiotherapy after surgery and chemotherapy, and an extensive review of the literature outlining the clinical features and treatment modality of spinal PNET.

Neurological manifestation of sacral tumors

An extensive analysis of the existing literature concerning sacral tumors was conducted to characterize their clinical manifestations. Although certain specific manifestations can be attributed to some of the tumor types, a more general pattern of clinical presentation of an expansive sacral lesion can be elaborated. Local pain with or without pseudoradicular or radicular radiation is the most frequent initial symptom and is usually followed by the manifestation of a lumbosacral sensorimotor deficit; bladder/bowel and/or sexual dysfunction appear throughout the natural course of disease.

Primary intraspinal primitive neuroectodermal tumor: report of two cases and review of the literature

BACKGROUND

Primary intraspinal primitive neuroectodermal tumor (PNET) is a very rare tumor entity. The optimal therapeutic approach is not known yet. We report on two women with primary intraspinal PNETs and review the literature. We describe the typical course of the disease, compare our patients to the other 17 cases reported until today, and discuss therapeutic options.

PATIENTS AND METHOD

Case A: In a 49-year-old woman with an intraspinal PNET at L2, laminectomy and a gross tumor removal was accomplished. Postoperative radiation was performed from T12 to L3 to a dose of 50.4 Gy. Subsequently she was treated with chemotherapy containing vincristine, cisplatinum and lomustine. Case B: A 29-year-old woman presented with intramedullary PNET lesions at T1-3 and T10-11. Due to the multifocal location, she received a primary craniospinal axis irradiation to a dose of 35.2 Gy plus a boost to the tumor region to a total dose of 53.2 Gy.

RESULTS

Both patients developed multilocular intraspinal relapses with meningeosis neoplastica 17 and 6 months from radiation therapy and underwent palliative chemotherapy. Case A died 23 months, case B 17 months after primary diagnosis.

CONCLUSION

Despite modern treatment with microsurgery, irradiation and chemotherapy in primary intraspinal PNETs, local relapse or dissemination in most cases lead to death within a few months. An improvement of treatment outcome can only be achieved by intensification through multidisciplinary treatment.

Primary intraspinal primitive neuroectodermal tumor: case report of a tumor arising from the sacral spinal nerve root and review of the literature

Primary spinal primitive neuroectodermal tumor (PNET) is a rare condition, 18 cases of which have been reported in the literature. In general, this tumor is treated with surgery followed by radiotherapy and chemotherapy, but prognosis is still poor. An 18-year-old female patient with an intradural, extramedullary mass at L3-L5 levels is presented in this report. This is the first female patient with primary spinal PNET at lumbar region, second patient with spinal nerve root origin, and third one with intradural, extramedullary localization ever reported in the literature. After surgery, she was treated with craniospinal radiotherapy and four cycles of combination chemotherapy regimen consisting of vincristine, cyclophosphamide, doxorubicin alternated with ifosfamide, and VP-16. Currently, she is asymptomatic and alive at 25 months. The histopathologic, radiologic, and clinical findings of the patient are presented and relevant literature is reviewed.

[Primitive neuroectodermal tumor of the cauda equina. Report of a case]

Primitive neuroectodermal tumors are malignant neoplasms whose classification has been controversial. Spinal primitive neuroectodermal tumors are rare and at the cauda equina are even less common. We report the case of a 40 year-old man with a history of progressive back pain and gait difficulty. After the diagnosis of a primitive neuroectodermal tumor of the cauda equina, the patient presented seeding to the intracranial subarachnoid space followed by a poor outcome. We review the literature of primary spinal primitive neuroectodermal tumors.

Primary primitive neuroectodermal tumor of the spinal cord: case report and review of the literature

We present the clinical, radiological, and pathological features of a primary primitive neuroectodermal tumor (PNET) that occurred in the thoracic spinal cord of a 69-year-old man. Magnetic resonance imaging (MRI) demonstrated on T1-weighted images a 2x1x5 cm isointense intraspinal mass with homogeneous contrast enhancement extending from the C7 to the Th3 level. There was no clinical or radiological evidence for the existence of an intracranial tumor. Histological examination revealed a small round cell tumor with rosette formation and immunohistochemical characteristics of a PNET. The patient is the oldest among the 20 cases with this rare spinal cord neoplasm reported so far in the literature; the previously published cases are briefly reviewed.

Primary intramedullary primitive neuroectodermal tumor of the spinal cord: case report and review of the literature

OBJECTIVE AND IMPORTANCE

Primary intraspinal primitive neuroectodermal tumors (PNETs) are rare. We report a case and review the literature.

CLINICAL PRESENTATION

A 22-year-old woman presented with rapidly progressive paraparesis and neurogenic bladder.

INTERVENTION

Preoperative computed tomography myelograms revealed a complete block at T12-L1, consistent with an intramedullary lesion. An urgent operation was performed with gross total tumor removal. The pathological findings were consistent with a PNET. Recurrence was noted within 10 weeks of surgery and has been somewhat responsive to chemotherapy and radiotherapy thus far. A review of the English literature shows that only 13 cases of primary intraspinal PNETs have been reported to date, and the present case is the second one in which the tumor was purely intramedullary. Most of the reported patients survived less than 2 years.

CONCLUSION

Primary intraspinal PNETs are rare tumors and carry a poor prognosis.

Primitive neuroectodermal tumor of the median nerve. Case report with cytogenetic analysis

The authors describe a malignant peripheral primitive neuroectodermal tumor (PNET) that originated in the median nerve in an elderly adult. After the diagnosis was made by biopsy, the patient underwent radical local resection with interpositional vein grafting of the brachial artery. The tumor had the typical appearance of a primitive neural tumor with small, round cells forming rosettes. It stained positively for both the Ewing's sarcoma/peripheral PNET antigen (HBA-71) and neuron-specific enolase, confirming its neural origin. Ultrastructural examination revealed dense core granules and suggested neural differentiation of the neoplasm. Cytogenetic analysis suggested a chromosome (11;22) translocation typical of peripheral PNET. Early reports consisted of tumors arising solely in peripheral nerves, but recent series have focused mainly on tumors arising in the soft tissues other than nerves. There are no other cases of true PNET of peripheral nerve in the modern literature that have been fully characterized by immunohistochemical, ultrastructural, and cytogenetic criteria. Although peripheral PNETs occur more commonly in children, this unusual neoplasm should be considered in the differential diagnosis of peripheral nerve neoplasms in adults. Early diagnosis is desirable because of its aggressive nature and poor outcome.

Primitive neuroectodermal tumour of the cauda equina

Primary primitive neuroectodermal tumours of the cauda equina are rare. We report a case and review the literature.