Peripheral Primitive Neuroectodermal Tumor Research Articles

Retroperitoneal primitive neuroectodermal tumour (PNET). A case report and review of the literature

Purpose We report a clinical case and present a brief review of the literature of peripheral primitive neuroectodermal tumour (PNET) as a rare disease. We discuss the difficult clinical and pathological diagnosis and the multidisciplinary approach to treatment of PNET. We debate radiosensitivity of extracranial recurrent retroperitoneal PNET. Methods and materials External beam radiation therapy was applied for a non-resectable local recurrence of retroperitoneal PNET in a 74-year-old woman. There were no distant metastases and our patient has refused chemotherapy. Results Local tumour control (LTC) was achieved after administration of a total dose of 60 Gy in 30 fractions by external beam 60 Cobalt radiotherapy. Conclusions PNET is an aggressive malignant tumour infiltrating lymphatics and metastasizing haematogenously. It requires a multimodality treatment. Late local recurrence of extracranial retroperitoneal PNET has shown high radiosensitivity, so local tumour irradiation could be a radical treatment even in non-resectable cases.

GLI1 Is a Central Mediator of EWS/FLI1 Signaling in Ewing Tumors

The Ewing Sarcoma Family Tumors (ESFT) consist of the classical pathologic entities of Ewing Sarcoma and peripheral Primitive Neuroectodermal Tumor. Occurring largely in the childhood through young adult years, these tumors have an unsurpassed propensity for metastasis and have no defined cell of origin. The biology of these aggressive malignancies centers around EWS/FLI1 and related EWS/ETS chimeric transcription factors, which are largely limited to this tumor class. Much progress has been made in the identification of a network of loci whose expression is modulated by EWS/FLI1 and its congeners. To date, little progress has been made in reconstructing the sequence of direct and indirect events that produce this network of modulated loci. The recent identification of GLI1 as an upregulated target of EWS/ETS transcription factors suggests a target which may be a more central mediator in the ESFT signaling network. In this paper, we further define the relationship of EWS/FLI1 expression and GLI1 upregulation in ESFT. This relationship is supported with data from primary tumor specimens. It is consistently observed across multiple ESFT cell lines and with multiple means of EWS/FLI1 inhibition. GLI1 inhibition affects tumor cell line phenotype whether shRNA or endogenous or pharmacologic inhibitors are employed. As is seen in model transformation systems, GLI1 upregulation by EWS/FLI1 appears to be independent of Hedgehog stimulation. Consistent with a more central role in ESFT pathogenesis, several known EWS/FLI1 targets appear to be targeted through GLI1. These findings further establish a central role for GLI1 in the pathogenesis of Ewing Tumors.

Primary Extraosseous Ewing Sarcoma of the Kidney With Level III Inferior Vena Cava Thrombus

Ewing sarcoma typically presents as a skeletal-based tumor, with rare instances of peripheral primitive neuroectodermal tumor (PNET) arising in the soft tissues. Few examples of organ-based PNETs have been previously described in the literature. These tumors are exceedingly rare as a primary renal neoplasm. To our knowledge, this is the first report documenting a primary extraskeletal Ewing sarcoma of the kidney with thrombus extending into the intrahepatic inferior vena cava thrombus (level III).

CT and MRI imaging features of peripheral primitive neuroectodermal tumors

To investigate the CT and MRI features of peripheral primitive neuroectodermal tumors (pPNETs) and evaluate its diagnostic value. The clinicopathological data of 9 surgically treated patients with peripheral primitive neuroectodermal tumors confirmed by pathology were collected, spiral CT (4/9) and MRI (6/9) plain scanning and dynamic enhancement scanning were performed preoperatively. Both CT and MRI scannings were performed in 1 case. Those CT and MR images were retrospectively reviewed and analyzed together with clinicopathological findings. The 9 lesions were located in skeletal muscles (n = 6), pelvic cavity (n = 2) and thoracic cavity (n = 1). The tumor size was 7.4-18.3 cm in diameter with a mean diameter of 11.6 cm. The shape of those lesions was round or ellipse (4 lesions) and irregular (5 lesions). The tumor usually presented as ill-defined masses, with homogeneous (n = 2) or inhomogeneous density (n = 7). Seven cases, including the 3 lesions located in the chest and pelvis, showed obvious necrosis and multilocular cyst formation. The tumors showed iso-density as that of the adjacent muscles on CT plain scans and moderate heterogeneous enhancement after intravenous injection of contrast agents. The features of the tumors on the MRI including slightly low signal intensity on SE T1-weighted imaging, iso-signal intensity or slightly high signal intensity on FSE T2-weighted imaging and heterogeneous dynamic delayed contrast-enhancement with obvious necrosis in most of them. Six cases had a lesion in the skeletal muscles, presented as a giant ill-defined masse surrounding bone and extended along neural route with bone destruction to varying degrees. Primitive neuroectodermal tumor is a kind of malignant tumor with proliferation of small, undifferentiated neuroectodermal cells, usually occurring in children or adolescent and frequently located in the extremities, chest cavity, pelvic cavity and chest wall. It typically presents as a large, ill-defined masse extending along neural route with heterogeneous and obvious enhancement after intravenous injection of contrast agents. The tumors located in the chest and pelvic cavities and some in the extremities show obvious necrosis and multilocular cyst formation, while some of the tumors in the extremities appear as homogeneous solid masses.

Peripheral primitive neuroectodermal tumor of head-neck region: our experience

To present four rare cases of peripheral primitive neuroectodermal tumors of different sites of head and neck region. Four cases of different age (range 8-40 years) and sex (three female, one male) with rare primitive neuroectodermal tumor of sinonasal region and neck are presented. Treatment options, biological behavior and prognostic outcome are discussed herewith. Two patients succumbed to the disease within four to six months of treatment; other two patients are still under follow-up depicting the aggressive nature of the tumor. Primitive neuroectodermal tumor belongs to the class of malignant round cell tumor. Immunohistochemistry plays a pivotal role in differentiating this tumor entity. Chemoradiation was tried, but local and systemic spread occurs early and holds poor prognosis. This case series is an attempt to describe the aggressive behavior of this rare tumor with high mortality.

Localised peripheral primitive neuroectodermal tumour (PNET) of the conjunctiva

A 16-year-old male presented with a 3-month history of an asymptomatic, enlarging conjunctival lesion. An excisional biopsy was performed and histologic and immunohistochemical examination showed characteristic features of a peripheral primitive neuroectodermal tumour (PNET) adjacent to a benign compound naevus. FISH analysis, demonstrating a split-signal at 22q12, confirmed the diagnosis. Staging investigations were negative confirming the primary nature of the lesion. The patient was treated with local wide re-excision and chemotherapy. He remains alive and well 29 months after initial resection.

4 cases of intraspinal primitive neuroectodermal tumor

Objective To investigate the diagnosis, patterns, pathology and treatment of primary intraspinal primitive neuroectodermal tumor (PNET). Methods The clinical materials of 4 intraspinal PNET, such as image data, histopathoiogy features, methods of treatment, were analyzed retrospectively. Results All cases were treated by surgery, 3 cases underwent total resection and 1 cases subtotal resection. 2 central primitive neuroectodermal tumors and 2 peripheral primitive neuroectodermal tumors were revealed by histopathological examination and immunohistochemical staining. Among the 4 cases who had been followed up, 3 underwent radiotherapy and chemotherapy, 1 did not receive any adjuvant therapy due to socioeconomic issues. Conclusions The age of intraspinal PNET is much older than the average age of manifestation for intracranial PNET. The history of intraspinal PNET is short. It is important that chemotherapy plans for cPNET are different from those for pPNET; Expression of CD99 offers an easy way of making a differential diagnosis between the central and peripheral PNET. Key words: Spinal canal; Primitive neuroectadermal tumor; Neurosugical procedures

Peripheral Primitive Neuroectodermal Tumour in a Lumbar Vertebra and the Liver of a Dromedary Camel ( Camelus dromedarius)

A 9-year-old castrated male dromedary camel developed weakness and ataxia, progressing to sternal recumbency and hindlimb paralysis. Necropsy revealed multiple liver tumours and a mass in the 3rd lumbar vertebra, compressing the spinal cord. The hepatic and vertebral masses consisted of uniform sheets of primitive cells, with perivascular pseudorosettes and small numbers of neuroblastic Homer-Wright rosettes. Immunohistochemically, the tumour cells were uniformly positive for vimentin and variably positive for neuron-specific enolase and glial fibrillary acidic protein. The histopathological and immunohistochemical findings indicated a peripheral primitive neuroectodermal tumour (pPNET) exhibiting neuroblastic, glial and ependymomatous differentiation, probably reflecting the tumour's primitive multipotential neuroepithelial nature. To the authors' knowledge, this is the first reported case in the camel of a pPNET, presumably intraosseous in origin with hepatic metastasis, and morphologically similar to Ewing's sarcoma in man.

Imaging findings of abdominal peripheral primitive neuroectodermal tumor: report of four cases with pathological correlation

Peripheral primitive neuroectodermal tumors (peripheral PNETs) are rare in the abdomen. We report the imaging findings of four peripheral PNETs arising in the abdomen. Three were ill-demarcated tumors and one was a well-demarcated tumor, with extensive local invasion and lymph node metastasis in two cases, respectively. The tumors are of inhomogeneous attenuation and heterogeneous enhancement after intravenous administration of contrast materials. Although their imaging manifestations cannot distinguish them from other sarcomas, recognition of these imaging features may be helpful in suggesting the possibility of peripheral PNETs in some cases.

Peripheral primitive neuroectodermal tumor of the urinary bladder in an Arab woman with history of squamous cell carcinoma: a case report

IntroductionPeripheral primitive neuroectodermal tumors of the urinary bladder are rare and tend to occur in an older age group than do their counterparts in bones and soft tissue.Case presentationWe report a case of peripheral primitive neuroectodermal tumor of the urinary bladder in a 67-year-old woman of Arab origin. She had undergone transurethral resection followed by chemotherapy because of pulmonary metastasized muscle-invasive squamous cell carcinoma of the bladder in 2005. One year later, she first presented with a history of repeated hematuria in our institution. Performing cystoscopy any tumor could be detected. Control cystoscopy two months later showed a tumor mass of 3 cm in diameter at another location than described for the first tumor. After perforating by transurethral resection partial bladder resection had to be done. Tissue specimen after pathological analysis revealed a peripheral primitive neuroectodermal tumor with tumor cells reactive to cluster of differentiation 99, neuron-specific enolase and S100 protein and stained negative for other markers such as cytokeratins, epithelial membrane antigen, desmin, smooth muscle actin, chromogranin and leucocyte common antigen. Staging computerized tomography was especially free from any hint on organ metastasis, but the patient died due to a cardiac problem only a few months later.ConclusionsTo the best of our knowledge, we report the eighth case of bladder peripheral primitive neuroectodermal tumors in literature and the first concerning an Arab patient. It is also the first presentation of a peripheral primitive neuroectodermal tumor patient with a history of squamous cell carcinoma of the bladder. As in other cases, expression of single-chain-type 1 glycoprotein and neural markers was positive and the disease was at an advanced stage at the time of diagnosis.

Immunogistokhimicheskaya kharakteristika i kriterii prognoza sarkomy Yuinga/PNET

A group of high-grade small round-cell neuroectodermal tumors developing in soft tissues and bones has been recently identified in children and young adults on the basis of the data of classical morphology and the results obtained by new techniques (cell culturing, molecular genetics, immunohistochemistry). To denote these tumors, the term "primitive peripheral neuroectodermal tumor" (PNET) has been proposed. The problem is of great practical importance in the differential diagnosis of formally similar malignancies (lymphoma, embryonal rhabdomyosarcoma, synovial sarcoma, small-cell variant of osteosarcoma), this makes PNET and Ewing's sarcoma be histogenetically and clinicodiagnostically of special scientific and practical interest.

MULTIPLE PRIMARY CRANIAL EWING'S SARCOMA IN ADULTHOOD

Ewing's sarcoma is a malignant bone tumor occurring most frequently in the long bones and flat bones as a solitary lesion during the first 2 decades of life. Ewing's sarcoma and peripheral primitive neuroectodermal tumor have recently been considered to be the same entity because of histological and molecular similarities. A 25-year-old man presented with swelling in the right parietal region. Magnetic resonance imaging scans showed 2 mixed intense mass lesions in the right parietal and left frontal areas with heterogeneous gadolinium enhancement. A computed tomographic scan revealed osteolytic changes of the inner calvarial bone. Ga-67 citrate scintigraphy demonstrated abnormal uptake in the right parietal and the left frontal areas consistent with the findings on magnetic resonance imaging scans. There was no uptake lesion beyond the cranium. The patient underwent surgical excision of the right parietal lesion. Histological examinations showed densely packed, small round cells with rosette formation. The cells had scanty clear cytoplasm, and regular vesicular and hyperchromatic nuclei. Electron microscopy showed little differentiation to neuronal tissue, indicating Ewing's sarcoma. After surgical treatment, conventional whole cranial irradiation of 40 Gy and chemotherapy were conducted. The tumor in the left frontal region disappeared. Follow-up examinations showed no evidence of recurrence 1 year after the surgery. Although quite rare, Ewing's sarcoma should be taken into consideration as a differential diagnosis of multiple cranial mass lesions in adulthood.

Primitive Neuroectodermal Tumor of Mediastinum in an Adult: A Case Report

A peripheral primitive neuroectodermal tumor (PNET) is a rare and aggressive malignant tumor, which most frequently occurs in children and young adults. The most well described site of origin is the chest wall. We report the case of a primitive neuroectodermal tumor in the anterior mediastinum with unusual CT findings.

Primary primitive neuroectodermal tumor of the orbit

Primitive neuroectodermal tumor (PNET) is a small round cell malignant tumor of neuroectodermal origin. Most of the PNETs occur in the central nervous system (CNS). PNETs recognized outside of CNS are diagnosed as peripheral PNET (pPNET). This tumor which expresses MIC-2 gene (CD99) seems to be least aggressive after complete tumor resection. We describe a rare case of PNET in a young girl.

Primary Epidural Peripheral Primitive Neuroectodermal Tumor of the Thoracic Spine -Case Report-

A 25-year-old male patient presented with an extremely rare primary spinal peripheral primitive neuroectodermal tumor (pPNET) manifesting as acutely progressive paraparesis and back pain. Neuroimaging and intraoperative examination showed that the tumor was confined to the epidural space of the thoracic spine. The patient was treated successfully by gross total resection of the tumor followed by chemotherapy and local radiotherapy. The present case illustrates the unexpected occurrence and important differential diagnosis of primary epidural pPNET of the thoracic spine in young patients presenting with progressive paraparesis and back pain.

Multimodality treatment approach in management of primary peripheral primitive neuroectodermal tumor of the orbit

Primitive neuroectodermal tumor is a small round cell malignancy which rarely involves the orbit. We report a case of a two-year old male child presenting as unilateral eccentric proptosis with extraconal and intraconal mass, diagnosed as primary peripheral primitive neuroectodermal tumor (pPPNET) on histopathology and immunohistochemistry. There is no defined consensus in the management of these tumors due to its rare presentation. We describe its distinguishing features with emphasis on multimodal and aggressive treatment approach which ensures appropriate management of these cases.

Carboplatin and paclitaxel adjuvant chemotherapy in primitive neuroectodermal tumor of the uterine corpus

Primitive neuroectodermal tumor of the uterine corpus (PNET) is rare and appears to have an aggressive clinical course. We report on a postmenopausal woman with optimal surgically cytoreduced advanced-stage PNET in which adjuvant combination chemotherapy with platinum and taxane agents was unsuccessful in extending her disease-free survival.

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.

Tumor neuroectodérmico primitivo periférico primário da órbita: relato de caso

The authors present a case of primary peripheral primitive neuroectodermal tumor of the orbit in a 10-month-old girl, which is the first case in the Brazilian literature. Clinical, radiologic and histopathologic features are discussed. The diagnosis was confirmed by immunohistochemical analysis which is essential to the diagnosis of small round cell tumors in the orbit.

Peripheral primitive neuroectodermal tumour of the chest wall invading lung with regional lymph node metastasis

Here we present the case of a 26-year-old man in whom peripheral primitive neuroectodermal tumour of chest wall origin invaded the left lung with regional lymph node metastasis. He underwent initial resection of the left chest wall tumour with combined left lower lobectomy, left S5 segmentectomy, and lymph node dissection in order to facilitate a definitive diagnosis and also to obviate the risk of fatal bleeding due to tumour invasion of the pulmonary artery. Histological examination of the resected sample revealed small round cell proliferation with neural differentiation, and confirmed lymph node involvement within the left lower lobe. EWS/FLI-1 fusion gene transcripts were detected by the reverse-transcription polymerase-chain reaction. Diagnosis of peripheral primitive neuroectodermal tumour was confirmed. After surgery, combination chemotherapy with cyclophosphamide, vincristine, doxorubicin, ifosphamide, and etoposide was given. Five years after resection, the patient remains alive and well, with no signs of recurrence.