SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
We present a case of primitive neuroectodermal tumor (PNET) arising from the diaphragm in a neonate. PNETs are rare malignant tumors that belong to the group of small, round, blue-cell neoplasms of childhood. To the best of our knowledge, a PNET originating from the diaphragm has not been previously reported.
We present a case of primitive neuroectodermal tumor (PNET) showing a unique differentiation phenotype based on ultrastructural observation. Rapidly growing tumor involving the retroperitoneum of a 68-year-old woman was characterized by histological findings including proliferation of diffuse poorly differentiated small round cells with scattered rosette formation similar to Homer-Wright type and by the ultrastructure demonstrating cytoplasmic neurosecretary granules and short cytoplasmic cilial structures. These cells revealed immunoreactivity only with neuron-specific enolase (NSE). We also observed a chromosomal translocation, t (11; 22) (q24; q12), which is an identical recurrent alteration found in the neoplastic cells in the spectrum of PNETs. These findings may support the explanation that tumor cells observed in our case shared phenotypes of both neuronal and ependymal cell lineages and give a unique insight suggesting the possible histogenesis of PNETs.
Current treatment for high risk and recurrent medulloblastoma (MB) and supratentorial primitive neuroectodermal tumors (stPNET) has a very poor prognosis in children. High dose chemotherapy (HDCT) and autologous stem cell rescue have improved survival rates. We present 19 patients (thirteen classified in the high risk group and six patients with recurrent disease) that received HDCT and autologous stem cell rescue. In the high risk group [Med Pediatr Oncol 38 (2002) 83], all patients underwent neurosurgical debulking. Standard chemotherapy was prescribed in 10 patients. Radiotherapy was given to 4 patients (all older than 4 years old). In the recurrence disease group [Childs Nerv Syst 15 (1999) 498], five patients underwent surgery. Radiotherapy was given to those who were not previously irradiated. The HDCT in twelve patients consisted of busulfan 4 mg/kg/day, orally over 4 days in 6-hourly divided doses and melphalan at a dose of 140 mg/m2/day by intravenous infusion over 5 min on day -1. Three patients additionally received thiotepa 250 mg/m2/day intravenously over 2 days and four patients additionally received topotecan 2 mg/m2/day over 5 days by intravenous infusion over 30 min. The other seven patients received busulfan and thiotepa at the same doses.Patient's stem cells were mobilized with granulocyte colony-stimulating factor at a dose of 12 microg/kg twice daily subcutaneously for four consecutive days. Cryopreserved peripheral blood progenitor cells were re-infused 48 h after completion of chemotherapy. With a median follow-up of 34 months (range 5-93) eight complete responses and one partial response were observed. Three patients died of treatment-related toxicities (15%). The 2 year event-free survival was 37.67+/-14% in all patients and 57+/-15% for the high risk group. Therefore we conclude that HDCT may improve survival rates in patients with high risk/recurrent MB and stPNET despite treatment toxicity.
BACKGROUND: A case of Primitive Neuroectodermal Tumor (PNET) of the kidney in a 27-year-old woman is presented. Few cases are reported in the literature with a variable, nonspecific presentation and an aggressive behaviour. In our case, a radical nephrectomy with lymphadenectomy was performed and there was no residual or recurrent tumour at 24-month follow-up. METHODS: The surgical specimens were formalin-fixed and paraffin embedded. The sections were stained with routinary H&E. Immunohistochemistry was performed. RESULTS: The immunohistochemical evaluation revealed a diffuse CD99 positivity in the cytoplasm of the neoplastic cells. Pankeratin, cytokeratin AE1/AE3, vimentin, desmin, S100, cromogranin were negative. The clinical presentation and the macroscopic aspect, together with the histological pattern, the cytological characteristic and the cellular immunophenotype addressed the diagnosis towards primary PNET of kidney. CONCLUSIONS: Since sometimes it is difficult to discriminate between PNET and Ewing's tumour, we reviewed the difficulties in differential diagnosis. These tumors have a common precursor but the stage of differentiation in which it is blocked is probably different. This could also explain their different biological behaviour and prognosis.
A 13-year-old boy presented with a primitive neuroectodermal tumor (PNET) with unusual extracranial extension. Precontrast computed tomography showed the tumor as a ring-shaped high-density area which was enhanced postcontrast, with a low-density center. Magnetic resonance imaging showed the tumor as a low-intensity area on the T1-weighted images with marked enhancement by gadolinium-diethylenetriaminepentaacetic acid, and high intensity on the T2-weighted images. The central area appeared as high intensity on both images, suggesting free methemoglobin. The tumor was subtotally removed. Histological examination demonstrated PNET. Despite irradiation (20 Gy) to the surgical site, and further tumor removal, he died 6 months later. This case showed PNET can extend extracranially. Diagnosis and treatment of such a tumor located extracranially and intracranially require careful consideration.
A primitive neuroectodermal tumor (PNET) presented as a cerebral hemispheric mass in a 33-year-old man. Bone marrow metastases were discovered 11 months later. A cell line (CHP707m) was derived from these metastases. In culture, the cells showed features of neuronal differentiation, forming short neurites and synthesizing low-molecular-weight neurofilament protein. Northern blotting showed the tumor cells express nerve growth factor (NGF) receptor messenger RNA, and fluorescence-activated cell-sorting demonstrated NGF receptors on the cell surface. Western blotting showed CHP707m NGF receptors are truncated. The receptors are functional; they bind iodine 125-labeled mouse NGF with an affinity of 1.6 x 10(-9) M, and short-term treatment with NGF induces expression by the tumor cells of the proto-oncogene, c-fos. Although CHP707m is the first central nervous system PNET cell line proven to express NGF receptors, immunohistological survey of tissue sections prepared from human central nervous system PNETs showed that 13 of 35 contained NGF receptor-positive tumor cells. Thus, more than one-third of such tumors might be responsive to the effects of NGF.
The neuroradiological findings in four cases of primitive neuroectodermal tumor of the cerebrum are described. These highly malignant neoplasms of childhood present as large, enhancing cerebral masses with extensive neovascularity. Cerebrospinal fluid seeding is common and distant extraneural metastases may occur.
Primitive neuroectodermal tumors (PNETs) account for one fifth of childhood brain tumors. Although little is known of the pathobiology of this tumor type, there are associations with both genetic syndromes and exposures to specific environmental agents. Progressive cerebellar atrophy predating the presentation of a primary brain tumor, in the absence of a genetic syndrome, has not been reported with PNETs. We report a case of a posterior fossa PNET occurring in association with long-standing cerebellar atrophy without evidence of a genetic syndrome. This case may represent an unrecognized paraneoplastic syndrome or a unique subtype of PNET.
Loss of heterozygosity on chromosome 17p13.3 is frequently observed in solid tumors, and the presence of a tumor suppressor gene has been predicted in this region of chromosome 17. We have analyzed a primitive neuroectodermal tumor sample exhibiting loss of heterozygosity at the D17S34 locus, a commonly used telomeric marker on the short arm of chromosome 17. The remaining allele showed a rearrangement. Cosmids spanning the D17S34 locus and probes from that region were used to demonstrate a 9-kb deletion within the D17S34 locus and were found to contain evolutionary, conserved sequences. Genetic alterations in this region may also affect expression of immediately adjacent genes, such as ABR, and could be a common mechanism in the causation of primitive neuroectodermal tumors.
OBJECTIVE: Within soft-tissue sarcoma, primitive neuroectodermal tumors have been shown to cover a wide spectrum of small round cell sarcomas, including Ewing's sarcomas (ES) and primitive neuroectodermal tumors (PNET). The role of the stem cell factor/kit pathway has been investigated in different human tumors especially in chronic myelocytic leukemia and gastrointestinal stromal tumor and an autocrine loop has been assumed in small cell lung carcinoma, and recently in ES and PNET. Our aim is to investigate the c-kit expression in ES and PNET and also to assessed if c-kit has any role in disease process. METHODS: We thoroughly searched the archives of the Department of Pathology, Faculty of Medicine, Cukurova University Turkey, between 2000 and 2004; and found 14 ES and 14 PNET paraffin embedded tissues. We carried out the detection of the c-kit expression by immunohistochemical staining. RESULTS: The patient's median age was 23.7 +/-14.6 (12 male and 16 female). Five were diagnosed as metastatic disease whereas 23 were diagnosed as non-metastatic disease at admission. The mean follow up period was 38.9 +/- 22.3 months. The main localization of the disease was lower extremity (32.1%), and others were as follows: head and neck 25%, thorax and abdomen 14.3%, pelvic and upper extremity 7.1% (11 were localized skeletal and 17 were extraskeletal). According to treatment modalities, 10 were treated with surgery alone, 11 with surgery and chemotherapy, and 7 with surgery, radiation therapy and also with chemotherapy. The primary tumor was lower than 5 cm in its dimension in 21 patients. While in 5 patients, tumor was more than 5 cm but did not exceed 10 cm, it was >10 cm in 2 patients. The c-kit expression was positive in 7 patients both cytoplasmic and membranously, whereas 8 patients were positive cytoplasmically. In 5 PNET patients, c-kit expression were stained immunohistochemically in over 50% and in 3 of ES patients. There was no significant correlation between c-kit expression and gender, localization, metastatic status, treatment modalities and tumor. Although in survival analysis, patients treated with surgery alone lived longer, while >50% of patients treated with c-kit expression lived for a shorter period. CONCLUSION: We suggest that therapy with tyrosine kinase inhibitor for PNET and ES patients may be an alternative in addition to standard therapy modalities, especially in patients non-responsive to standard therapy.
A retrospective review of 36 children diagnosed with a supratentorial primitive neuroectodermal tumor (PNET) at the Hospital for Sick Children was performed for the period 1970-1995. All children but one received their initial treatment at our institution. There were 18 males and 18 females and the median age at diagnosis was 35 months. Twenty-two PNETs were lobar, 3 were deep in the hemisphere, and 10 were located in the pineal region. One child presented with intracranial leptomeningeal disseminated disease. The tumors were mostly undifferentiated although 22 had some evidence of differentiation along one or more neuroepithelial lines. Five children had a biopsy, 24 had subtotal resection, and 7 had gross total resection. Twenty-six children had adjuvant radiotherapy and 13 had chemotherapy. At last follow-up 30 patients were dead and 6 were alive. The median survival was 23 months and the 2, 3, and 5 year survivals were 50%, 34%, and 18% respectively. All of the survivors received craniospinal radiation and 4 received chemotherapy. There was a statistically significantly worse survival in young children. There was a trend to better survival in children treated since 1984, and in children undergoing gross total resection. Because of the extremely poor survival, we recommended that all children undergo gross total resection followed by chemotherapy. For children older than 3 years of age craniospinal radiation should also be given.
BACKGROUND: Only three cases of Ewing's sarcoma-primitive neuroectodermal tumor (ES-PNET) occurring in the vagina have been previously reported. CASE: A 30-year-old Chinese woman presented with a vaginal mass measuring 5 cm in greatest dimension. The tumor was composed of solid sheets of undifferentiated small round cells with numerous Homer-Wright rosettes. Immunohistochemically, it was positive for CD99, FlI-1 protein, synaptophysin, neuron-specific enolase, vimentin, and S-100 protein. The patient underwent wide local excision of the tumor and subsequent total abdominal hysterectomy with postoperative chemotherapy and radiotherapy. She is disease-free 36 months after the initial surgery. CONCLUSION: This is a rare case of ES-PNET occurring in the vagina and the first showing many distinctive Homer-Wright rosettes. A review of literature indicates that vaginal or vulvar ES-PNET affects younger women, and it may have a relatively favorable outcome.
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.
A case of an epidural spinal peripheral primitive neuroectodermal tumor (pPNET) in a 13-year-old girl is presented. The tumor was disseminated at the moment of diagnosis, thus only diagnostic oligobiopsy of the epidural mass was performed. Histologically the tumor was composed of small round blue cells. The neoplastic cells expressed MIC2 and features of neural differentiation on immunohistochemical staining (neuron-specific enolase, synaptophysin and NCAM positivity). Fluorescent in situ hybridization (FISH) analysis was performed for the final diagnosis and the translocation t(11;22)(q24;q12) was detected. The present case emphasizes the usefulness of FISH in differential diagnosis of tumors, especially when only routinely fixed material is available.
We describe a rare case of a primary primitive neuroectodermal tumor (PNET) in the lung of a 17-year-old girl. Grossly, the tumor, located in the right lower lobe, was relatively well-circumscribed and whitish to yellowish in color with scattered hemorrhagic necrosis. Microscopically, the tumor was composed of ovoid to polygonal cells with a high nuclear to cytoplasmic ratio and relatively scant cytoplasm, arranged in solid sheets with intervening fine fibrovascular stroma. Immunohistochemically, the tumor was positive for the MIC2 gene product, whereas AE1/AE3, CAM5.2, and a variety of neuroendocrine markers such as chromogranin A, synaptophysin, and ProGRP, were negative. Three months after the lobectomy, recurrent tumors were noted in the mediastinum and right thoracic wall, and she died despite combined chemotherapy and radiation therapy. In this case cytogenetic analysis showed a hypertriploid karyotype with multiple numerical and structural chromosomal aberrations, but failed to disclose distinct evidence of translocation between chromosome 11 and 22. However, the reverse transcriptase-polymerase chain reaction (RT-PCR) demonstrated EWS/FLI-1 fusion transcripts, confirming the histopathologic diagnosis of PNET. This case indicates that the primary pulmonary PNET is a highly aggressive neoplasm occurring at a young age, and should prompt combined systemic chemotherapy, even though it is organ-confined.
BACKGROUND: Peripheral primitive neuroectodermal tumor (PNET) of the vulva is an extremely rare disease, and, to our knowledge, only two cases have been previously reported. CASE: A 45-year-old woman presented with a mass in the right labium major. Three years after removal of the tumor, she noticed a new lesion in the same place and underwent a partial vulvectomy. The imprint cytology of the recurrent tumor showed a monomorphic appearance, composed of small round cells with scant cytoplasm against a hemorrhagic background. These tumor cells were loosely connective, but rosettelike structures were observed focally. On pathologic examination, the neoplasm was composed of small round tumor cells showing sinusoidal, diffuse or micropapillary growth. Immunohistochemically, the neoplastic cells stained positively for neuron-specific enolase, vimentin and HBA 71 and negatively for cytokeratin, HBA 45 and muscle-specific actin. The morphologic characteristics of the disease were well expressed in the imprint cytology, and this influenced the selection of immunohistochemical studies. CONCLUSION: Cytologic examination for vulvar tumors, even imprint cytology, can be a useful tool in obtaining an accurate pathologic diagnosis of a rare disease, such as peripheral PNET.
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 multiply 18 cm multiply 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 confirmed 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 differential 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.
OBJECTIVE: To study the pathological characteristics of primitive neuroectodermal tumor (PNET) of bone and soft tissue. METHOD: Five patients with bone and soft tissue of PNET (2 men and 3 women) were studied by light microscope and immunohistochemistry. The age of the patients was 18, 18, 43, 14, 32 years and the primary sites of involvement were the ilium (n = 2), axillary fossa (n = 1), condyle of femur (n = 1), and diploe (n = 1). X-ray films showed bone osteolytic destruction, and no periosteal reaction or calcification. Surgery was performed in the patients. RESULT: All patients received combined chemotherapy and 3 received radiotherapy. Three patients died of metastatic tumor of lung 20, 13, and 5 months after invasion. 1 patient metastatic tumor of lung 20 months after invasion, and 1 patient bone extensive metastasis 1.5 months after surgery. CONCLUSION: The treatment of PNET of bone and soft tissue awaits further study.