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PubMed2006

Peripheral primitive neuroectodermal tumor of the cavernous sinus: case report.

OBJECTIVE: Ewing sarcoma/peripheral primitive neuroectodermal tumors (pPNET family) are small, round, blue cell tumors that have a decided predilection for young patients and commonly arise in bone and soft tissue. We are reporting a rare case of cavernous sinus pPNET in a 48-year-old woman. CLINICAL PRESENTATION: A 48-year-old woman presented with headache, ipsilateral maxillary, and ophthalmic and oculomotor nerve palsies. Neuroimaging revealed a cavernous sinus lesion. INTERVENTION: The patient underwent debulking of the tumor, and the diagnosis of a pPNET was made based on histological, immunohistochemical, and molecular genetics (EWS-FLI1 fusion gene) findings. Bone scans, bone marrow aspiration, and biopsy and chest computed tomographic scans showed no evidence of systemic involvement. The patient had adjuvant treatment with radiotherapy and chemotherapy. After 14 months, the patient had no neurological deficits, and neuroimaging showed stable disease, although some chemotherapy complications occurred. CONCLUSION: This is a case of cavernous sinus pPNET in a 48-year-old woman, in whom the diagnosis is supported by the presence of EWS-FLI1 fusion gene. This seems to be the first reported case of a cavernous sinus pPNET confirmed by molecular genetic analysis.

Cavernous Sinus↗
PubMed2004

A peripheral primitive neuroectodermal tumor with generalized bone metastases in a puppy.

A peripheral primitive neuroectodermal tumor (pPNET), most consistent with a human Ewing's sarcoma, is described in a 5-month-old male Australian Shepherd puppy. The first tumor site detected was in the left frontal bone of the skull with apparent subsequent rapid metastases to multiple sites in the axial and appendicular skeleton and bone marrow, kidneys, and perihyphophyseal meninges. Radiographically, all bone lesions were lytic and there was also a humeral bone fracture. Histologically, the tumor was diagnosed as a small round blue cell tumor. At this stage, the differential diagnosis included a lymphoma, rhabdomyosarcoma, and a PNET of the peripheral nervous system. However, the cells had positive expression of triple neurofilament antigens as detected immunocytochemically. The cells were negative for a broad panel of canine-specific leucocyte cell marker antigens for desmin, smooth muscle actin, synaptophysin, and CD99. Ultrastructurally, the cells contained occasional dense core neurosecretory granules and intermediate filaments with intercellular desmosomal-like junctions and abundant glycogen clusters. Based on the age of the dog, the clinical history, the distribution of gross lesions, histologic characteristics of a small round blue cell tumor, and immunocytochemical and ultrastructural evidence of neuroectodermal differentiation, a diagnosis of a pPNET similar to a human Ewing's sarcoma was made.

Animals↗
PubMed1981

Primitive neuroectodermal tumors of childhood. An approach to therapy.

Primitive neuroectodermal tumors are found in the cerebrum of children and young adults. The are clinically highly malignant and have rapid course from diagnosis to death. Their microscopic pathology reveals 90% to 95% nondifferentiation, frequent mitoses, and small dark cells with no observable cytoplasm. This paper discusses the treatment of three children with this tumor with a combination of surgery irradiation, and combination chemotherapy. The results of this approach are compared with previous reports in the literature. The average survival in this series is 24 months versus approximately 8 months reported in the literature.

Adolescent↗
PubMed1992

Multidrug resistance gene expression in pediatric primitive neuroectodermal tumors of the central nervous system.

Pediatric primitive neuroectodermal tumor (PNET) is a malignancy of the central nervous system currently treated with surgery, radiation therapy, and chemotherapy. Despite aggressive management, tumors recur in almost one-half of all patients. Drug resistance of tumor cells may, in part, explain the poor outcome. Resistance to chemotherapeutic agents may be related to expression of the multidrug resistance gene (MDR1) and its protein product, P-glycoprotein. The role of MDR1 in 16 instances of PNET was investigated using Western blot analysis to detect the expression of P-glycoprotein, messenger ribonucleic acid (mRNA), polymerase chain reaction to detect MDR1 mRNA expression, and Southern blot analysis to assess gene amplification. Analysis of proteins extracted from 15 tumors revealed that two of the 15 patients expressed detectable levels of P-glycoprotein. Polymerase chain reaction of ribonucleic acid from 12 PNET's revealed that six of the 12 patients (four of 10 de novo tumors and both recurrent tumors) expressed MDR1 mRNA. Southern blot analysis of deoxyribonucleic acid from 16 PNET's revealed no evidence of MDR1 amplification in any tumor. This is the first report of MDR1 expression in pediatric brain tumors. These data suggest a possible role for MDR1 in de novo and acquired drug resistance in PNET's.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2006

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.

Cervical Vertebrae↗
PubMed1999

Primary primitive neuroectodermal tumor (PNET) of the kidney: a case report.

OBJECTIVES: Primary primitive neuroectodermal tumor (PNET) of the kidney is an extremely rare entity and the case is presented to highlight the histological diagnostic problems. METHODS AND RESULTS: A 23-year-old female presented with a lump in the left hypochondrium that had appeared 3 months, earlier, which suggested a malignancy on radiological investigation. The nephrectomy specimen revealed a large tumor mass with only a small portion of normal renal parenchyma. Histology showed a small cell malignant tumor and the diagnosis of PNET (primary of kidney) and small cell carcinoma were suspected. The tumor showed NSE and vimentin positivity and cytokeratin negativity, which conformed with the diagnosis of PNET. CONCLUSION: The biological behaviour of PNET is more aggressive, with rapid progression and infiltration into the surrounding tissues and distant metastases. Thus it differs from the small renal cell malignancies and hence recognition of this tumor as a distinct entity is essential.

Adult↗
PubMed1999

Late radiation injury following hyperfractionated craniospinal radiotherapy for primitive neuroectodermal tumor.

PURPOSE: To document the late radiographic change following hyperfractionated craniospinal radiotherapy for primitive neuroectodermal tumor. METHODS AND MATERIALS: We reviewed long-term MRI scans on 21 patients with standard risk and high risk primitive neuroectodermal tumor treated with hyperfractionated radiotherapy following surgical resection. High risk patients also received adjuvant chemotherapy. Long-term scans were defined as scan obtained at least 1 year from diagnosis. Clinical follow-up data was available on all patients. RESULTS: Twelve of 21 patients had MRI evidence of necrosis, telangiectasia, white matter changes, basal ganglia change, or cerebral atrophy consistent with radiation injury. No patient required treatment for the radiographic change. CONCLUSIONS: Slightly over half of the patients had evidence of long-term radiation effect following craniospinal axis radiotherapy. However, no patient had frank clinical symptoms related to the radiographic findings.

Adolescent↗
PubMed1994

Ultrastructure of the primitive neuroectodermal tumors (PNET).

We report a prospective series of consecutive cases of primitive neuroectodermal tumor (PNET) studied by electron microscopy. Virtually all specimens showed a differentiation along neuroblastic lines as evidenced by the presence of neurites, dense-cored vesicles, microtubules and adhesive plaque junctions. We observed also numerous intracytoplasmic cilia and autophagic vacuoles. Synaptic specializations were only rarely seen. We conclude that PNET is a tumor category which is not undifferentiated ("primitive") and clearly exhibits features of neuroblastic differentiation.

Adolescent↗
PubMedDate not supplied

Peripheral primitive neuroectodermal tumor (PPNET) of pelvic origin: report of a case arising from an unusual location.

A peripheral primitive neuroectodermal tumor arising from the abdominopelvic cavity is reported in a 24-year-old young male without any previous remarkable pathology. He was admitted to our hospital with complaints of urinary symptoms (acute urinary retention) and mild intestinal occlusion that had been present for three months. Physical examination and CT scan revealed a pelvic mass occupying the entire pelvic cavity. The diagnostic workup included a CT-guided biopsy which defined the tumor as a sarcomatous type. Radical surgery was performed including tumor resection, pelvic exenteration (bladder and prostate gland) and urinary and fecal diversion. Adjuvant chemotherapy (VAIA) was delivered once the histology was confirmed. We reviewed the available literature focusing on the varied nomenclature of this tumor (peripheral neuroepithelioma, Askin's tumor, Ewing's extraosseous tumor, peripheral adult neuroblastoma, peripheral primitive extracranial neuroectodermal tumor (PPNET), the clinical features, the role of diagnostic imaging techniques, pathologic assessment and controversial therapeutic management. In addition, the prognosis and survival of this rare condition were analyzed.

Adult↗
PubMed1992

Establishment and characterization of a human primitive neuroectodermal tumor cell line from the cerebral hemisphere.

The primitive neuroectodermal tumors (PNET) comprise a class of malignant nervous system neoplasms that afflict children. These tumors consist of cells that are morphologically identical to the primitive neuroepithelial cells normally seen in early stages of neural embryogenesis, supporting the notion that PNET result from a disturbance in the process of normal neuronal or glial differentiation. In the central nervous system, PNET occur most commonly in the cerebellum (medulloblastomas), but only occasionally in the cerebral hemispheres. We report here the establishment and characterization of a new human cell line (PFSK) derived from a PNET from the cerebral hemisphere of a child. The growth characteristics of PFSK cells were typical of an immortalized, transformed cell line. Cytogenetic and molecular genetic studies showed that three different sublines were present. In one of these sublines, sequences from chromosome 17 had been lost during establishment in culture. Immunocytochemical studies showed that PFSK cells expressed nestin, an intermediate filament protein normally expressed by neuroepithelial stem cells during neurulation. The PFSK cells did not express antigens typically found in terminally differentiated neurons or glia, indicating that this tumor cell line might represent neuroepithelial stem cells prior to commitment to a neuronal or glial lineage.

Brain Neoplasms↗
PubMed1996

Surveillance imaging in children with primitive neuroectodermal tumors.

Controversy surrounds the benefits of routine surveillance magnetic resonance or computed tomographic imaging for monitoring children after resection of primitive neuroectodermal tumors. A recent study suggested that serial imaging studies detect only a small minority of tumor recurrences in patients with symptoms. The authors concluded that even in patients with recurrence documented by imaging, no patient with a recurrence survived long (average, 5 mo) and that surveillance scanning is of little clinical value in children with primitive neuroectodermal tumors. We reviewed our experience with 25 patients (28% of our total series) who presented to the Children's Hospital Los Angeles, Los Angeles, CA, from 1985 to 1993 with recurrent tumors after surgery and adjuvant therapy. Recurrent tumors were detected on routine imaging in 19 asymptomatic patients (76%) and in 6 symptomatic patients (24%). Recurrences were documented 15 months (mean) after the initial diagnosis in asymptomatic children and 5 months (mean) after the initial diagnosis in children with symptoms of recurrent tumor (P < or = 0.01). Asymptomatic patients with recurrence documented on serial imaging had prolonged survival when compared with those who were symptomatic (P < or = 0.05). The surviving patients with recurrence remained alive for more than 24 months after documentation of recurrence. Early detection of local tumor recurrence by surveillance scanning may provide a critical therapeutic window for successful treatment with aggressive or novel therapies.

Adolescent↗
PubMedDate not supplied

Coexistence of cerebellar primitive neuroectodermal tumor and cerebellar dysplasia: case report.

It has been speculated that the cerebellar primitive neuroectodermal tumor (PNET) in part recapitulates stages in the maturation of normal human neuroblasts. One theory suggests that these tumors may arise from "primitive cells" or "remnants" of the external granular layer of the cerebellum, which forms a subpial, proliferative zone that gives rise to neurons of the internal granular layer and stellate and basket cells. In the present report, the coexistence of marked cerebellar cortical disorganization and cerebellar PNET is described in a 1-year-old boy. The abnormal dysplastic cortex was in close proximity as well as contiguous to the tumor. Although minor degrees of cerebellar dysplasia may be found incidentally, the coexistence of a severe malformative process contiguous to cerebellar PNET merits the consideration of a possible pathogenetic association between aberrant neuronal migration or maturation and the development of PNET in this patient.

Cerebellar Ataxia↗
PubMed1991

Immunohistochemical characterization of primitive neuroectodermal tumors and their possible relationship to the stepwise ontogenetic development of the central nervous system. 2. Tumor studies.

Thirty-five selected intracranial tumors qualifying as primitive neuroectodermal tumors (PNETs) were investigated; these included medulloblastomas, cerebral neuroblastomas, pinealoblastomas, retinoblastomas, polar spongioblastomas, ependymoblastomas. For control purposes 11 tumors, including glioblastomas (small cell, spongioblastic variants), one anaplastic astrocytoma (astroblastic component), anaplastic oligo-astrocytomas, gangliogliomas, one primary melanoblastoma, and one pineal germinoma, were also studied. Six neuronal markers, i.e., synaptophysin, chromogranin A, neuron-specific enolase (NSE), neurofilament protein (NFP) (160 kDa, 200 kDa, 70 and 200 kDa), and six other markers (glial fibrillary acidic protein, S-100 protein, vimentin, myoglobin, desmin, cytokeratin) were investigated immunohistochemically. A certain recapitulation of the ontogenetic development of neuronal differentiation in PNETs is given by the fact that chromogranin A immunoreactivity can regularly be seen already in poorly differentiated neurons and synaptophysin in well-differentiated ones. Immunostaining for NFPs showed different results depending on the subunit investigated. NSE reaction gave different results even within the single tumor groups. This study is, to the best of our knowledge, the first attempt to evaluate and compare, by combined morphological and immunohistochemical methods, PNETs without and with different stages of cellular differentiation with the stepwise differentiation of the human embryonic neuroectoderm.

Adolescent↗
PubMed1997

EWS-Fli1 antisense oligodeoxynucleotide inhibits proliferation of human Ewing's sarcoma and primitive neuroectodermal tumor cells.

The translocation t(11;22) is a common chromosomal abnormality detected both in Ewing's sarcoma and in primitive neuroectodermal tumor cells. The translocation results in an EWS-Fli1 fusion gene, made up of the 5' half of the EWS gene on chromosome 22 fused to the 3' half of the Fli1 gene on chromosome 11. Recent studies have evaluated possible roles of the fusion gene products. However, the biological significance of EWS-Fli1 is still unknown. Using a competitive polymerase chain reaction technique, we show here that there might be a correlation between the expression levels of the EWS-Fli1 fusion gene and the proliferative activities of Ewing's sarcoma and primitive neuroectodermal tumor cells. When the EWS-Fli1 expression is inhibited by antisense oligodeoxynucleotides against the fusion RNA, the growth of the tumor cells is significantly reduced both in vitro and in vivo. The data further indicate the growth inhibition of the cells by the antisense sequence might be mediated by G0/G1 block in the cell cycle progression. These results suggest that EWS-Fli1 may play an important role in the proliferation of the tumor cells, and the EWS-Fli1 fusion RNA could be used as a target to inhibit the growth of Ewing's sarcoma and primitive neuroectodermal tumor with the specific antisense oligonucleotide.

Cell Cycle↗
PubMed2006

Long-term relapse-free survival with supratentorial primitive neuroectodermal tumor in an adult: a case report.

OBJECTIVE: In adults, supratentorial primitive neuroectodermal tumor (sPNET) is a very rare undifferentiated embryoblastic neoplasm. Prognosis is worse in comparison to infratentorial medulloblastoma. Older age appears to be prognostically favorable. At present, 5-year survival rates remain below 50% in all age groups. Survival longer than 15 years in an adult has only been reported once so far. CASE REPORT: In 1987, a 33-year-old-male patient presented with seizures following a six-month's history of dizziness. CT- and MRI-scans revealed a right occipital tumor with moderate contrast enhancement. The tumor was completely removed. The original histological diagnosis was that of an undifferentiated sarcoma, malignant hemangioendothelioma, grade III. The patient was treated by CyVADIC chemotherapy and conventional radiation therapy (60 Gy). Admission for another reason in 2003 led to a re-evaluation of the original diagnosis. Microscopy revealed a malignant, highly cellular, poorly differentiated tumor with a desmoplastic component. Up to 20% of tumor nuclei were labeled for Ki-67. Almost all cells were stained for neuron specific enolase and NGF-Rp75, with neuronal and glial markers being present to a variable extent. According to these findings, the diagnosis was changed to a sPNET (WHO IVdegrees ). Other tumor entities were excluded by immunohistochemistry. CONCLUSIONS: Although the prognosis of sPNET is reported to be poor, a small fraction with a rather benign biological and clinical behavior exists. Parameters determining long-term-survival in sPNET are not yet known. Whenever possible, complete surgical resection should be attempted followed by postoperative radiotherapy. The value of chemotherapy is an issue of continuous investigation.

Adult↗
PubMed1996

p53 gene mutation in cerebral primitive neuroectodermal tumor in Taiwan.

p53 mutation has been rarely reported in cerebral primitive neuroectodermal tumors (PNET). To determine the significance of p53 mutations in the development of cerebral PNET, we studied cerebral PNET samples from 14 patients, 8 females and 6 males with a mean age of 38 years (range 10 months to 77 years) who had total or subtotal surgical resection. Histological typing of PNET with neuronal (N) and non-neuronal (NN) differentiation groups revealed 8 and 6 cases, respectively. Six (43%) of the 14 patients had p53 mutation. The p53(+) and p53(-) groups had an age range of 19-77 with a mean of 49 years and 10 months to 57 years with a mean of 30 years, respectively. p53 expression between the PNET-N and PNET-NN groups was 5 of 8 (62.5%) and 1 of 6 (16.7%), respectively. The mutations contained 3 transitions, 2 transversions and 1 frameshift; none of them occurred at the site of 'hot-spot' residues (codons 175, 248, 273). The results suggest that: (1) p53 mutation in cerebral PNET tends to show a higher incidence of neuronal differentiation and occurs in the older age group in Taiwan, (2) there was no difference in survival time between the PNET-N and PNET-NN groups (7 months and 6 months) (P = 0.54), and between p53(+) and p53(-) groups (6 months and 7 months) (P = 0.57), and (3) PNET may be an entity of a heterogenous group of tumors with different genetic mechanisms controlling their trends of differential lineage. Further studies are needed to determine the significance of p53 mutations in PNET development, especially the role of carcinogens in the genesis of PNET in Taiwan.

Adolescent↗
PubMed2006

Primitive neuroectodermal tumor: rare, highly aggressive differential diagnosis in urologic malignancies.

OBJECTIVES: Peripheral primitive neuroectodermal tumor (PNET) is a highly aggressive neoplasm belonging to the Ewing family of tumors. It is characterized by the expression of MIC2 and neural markers (eg, neuron-specific enolase, synaptophysin, S-100, vimentin, Leu-7), and the presence of the EWS-FLI1 translocation. METHODS: We performed a MEDLINE search for PNET in urologic malignancies. Additionally, we report on 2 cases of renal and 1 case of bladder PNET. The data obtained by reviewing patients with renal PNET were analyzed using Kaplan-Meier analysis. RESULTS: Renal PNET is diagnosed in young adults (median age 24 years). In contrast, the incidence of bladder PNET seems to be dependent on a defective immune mechanism. Patients often present with pain (84%), palpable tumor (60%), and hematuria (38%). The radiologic findings are uncharacteristic; therefore, the diagnosis should be based on the histologic and immunohistochemistry findings. Renal and bladder PNET are both often diagnosed at an advanced stage and, therefore, the prognosis is poor, despite aggressive multimodal treatment (surgery, polychemotherapy, radiotherapy). We identified palpable tumor masses (log-rank test, P = 0.0027) and synaptophysin expression (log-rank test, P = 0.0422) as prognostic unfavorable markers for renal PNET. CONCLUSIONS: Renal PNET should be considered in young patients who present with the classic triad of renal cancer, hematuria, and pain and palpable tumor. Once PNET is diagnosed, multimodal treatment (radical surgery, multidrug chemotherapy, radiotherapy) must be initiated. Despite this, the prognosis is poor if distant metastases are present. Furthermore, palpable tumor masses and synaptophysin expression are associated with a shorter cancer-specific survival.

Adult↗
PubMed2003

Unusual aberration involving the short arm of chromosome 11 in an 8-month-old patient with a supratentorial primitive neuroectodermal tumor.

An 8-month-old baby girl with a supratentorial primitive neuroectodermal tumor showed an unusual aberration involving the short arm of chromosome 11. Seven abnormal metaphase cells had 49 chromosomes with trisomies of chromosomes 9 and 13, and partial trisomies of 1q and 18p. One homologue chromosome 11 was strikingly abnormal showing a long acrocentric-like form, which was composed of the long arm of chromosome 1 and an addition to the short arm of chromosome 11. This was characterized by fluorescence in situ hybridization using a partial arm chromosome-painting probe.

Chromosome Aberrations↗