1/70. Thoracoabdominal peripheral primitive neuroectodermal tumors in childhood: radiological features.Peripheral primitive neuroectodermal tumors (PNET) are extremely uncommon, malignant neoplasms affecting mostly children and young adults. We retrospectively reviewed the clinical data and radiological studies of four such cases. All cases were pathologically proven. Plain films, US, and CT scans were used. The youngest child had a huge pelvic tumor and two adolescents each had a chest wall (Askin) tumor. The fourth patient had a most unusual location of the PNET in the anterior mediastinum. The CT findings are emphasized. We emphasize that the markedly abnormal CT findings are not specific for PNET.- - - - - - - - - - ranking = 1keywords = neoplasm (Clic here for more details about this article) |
2/70. A para-testicular primitive neuroectodermal tumor in an adult: a case report and literature review.OBJECTIVE: The authors describe the salient clinical, radiologic and histopathologic features of an extremely rare para-testicular primitive neuroectodermal tumor in a 25 year-old man. INTERVENTION: Excisional biopsy of the tumor en bloc was performed. Adjuvant VAdriaC-based chemotherapy (vincristine, doxorubicin, and cyclophosphamide) was given post-operatively. MAIN OUTCOME MEASURES: Histopathologic examination and immunohistochemical studies were performed on formaldehyde-fixed, paraffin-embedded tumor tissue. RESULTS: Histologic examination showed an undifferentiated small cell tumor. The tumor cells stained positively with MIC-2, a marker specific for primitive neuroectodermal tumors. The patient is 12 months post surgery and has completed adjuvant chemotherapy with no evidence of recurrent disease. CONCLUSIONS: This highly unusual, peripheral primitive neuroectodermal tumor should be considered in the differential diagnosis of undifferentiated small cell neoplasms of the genitourinary system in adults, from the kidney to the testicle. We present a patient with a PNET treated based on a Ewing's family of tumors protocol.- - - - - - - - - - ranking = 1keywords = neoplasm (Clic here for more details about this article) |
3/70. Peripheral primitive neuroectodermal tumour of the kidney: CT findings.Peripheral primitive neuroectodermal tumour in the kidney is a rare entity with high malignant potential. The distinctive demographic, clinical and radiological findings, as described in the present case, should suggest this aggressive tumour in the differential diagnosis of renal neoplasms in adolescents.- - - - - - - - - - ranking = 1keywords = neoplasm (Clic here for more details about this article) |
4/70. Primary pulmonary primitive neuroectodermal tumor (PNET). A case report.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.- - - - - - - - - - ranking = 1keywords = neoplasm (Clic here for more details about this article) |
5/70. Intracranial Ewing sarcoma/'peripheral' primitive neuroectodermal tumor of dural origin with molecular genetic confirmation.Ewing sarcoma/'peripheral' primitive neuroectodermal tumor (ES/pPNET) is the designation given to a family of small cell neoplasms that typically arise in bone or soft tissue and are unified by their common expression of the MIC2 antigen and specific translocations involving a gene on chromosome 22q12 [the most common being t(11;22)(q24;q12)]. ES/pPNET of intracranial origin is extraordinary. We report the case of a 6-year-old boy with a large left frontal region mass that adhered to dura and was extracerebral at surgery. Histologic study revealed a high-grade, undifferentiated-appearing neoplasm of small cell type that was negative on immunostudy for glial fibrillary acidic protein, synaptophysin, desmin, leukocyte common antigen, smooth muscle actin and epithelial membrane antigen, but positive for vimentin and neuron-specific enolase and diffusely labeled by antibody O13 (which recognizes the MIC2 gene product). rna-based polymerase chain reaction assay confirmed the diagnosis of ES/pPNET by demonstrating fusion transcripts indicative of t(11;22) translocation. Bone scan, computerized tomography of the chest and bone marrow examination revealed no systemic tumor. The limited observations published to date suggest that primary intracranial ES/pPNET is most likely to present in childhood as a circumscribed, contrast-enhancing and dural-based extracerebral mass. It must be distinguished from a variety of small cell neoplasms, particularly PNETs of central neuroepithelial origin.- - - - - - - - - - ranking = 3keywords = neoplasm (Clic here for more details about this article) |
6/70. Intracranial esthesioneuroblastoma. A light and electron microscopic study.A 31 year-old black woman with unilateral facial dysesthesia was found to have an intracranial parasellar mass that extended into the sphenoid sinus. By light microscopy, the neoplasm appeared as nests of poorly differentiated neuroblasts in a finely fibrillary stroma and was diagnosed as an esthesineuroblastoma. Electron microscopy confirmed the neuroblastic nature of the tumor with demonstration of neurites containing neurofilaments and neurotubules, synapses and dense cored biogenic amine granules in perikarya and processes. This neoplasm was further characterized by the presence of numerous dystrophic axons that were evident only by electron microscopy.- - - - - - - - - - ranking = 2keywords = neoplasm (Clic here for more details about this article) |
7/70. Peripheral primitive neuroectodermal tumor of the vulva: report of a case with imprint cytology.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.- - - - - - - - - - ranking = 1keywords = neoplasm (Clic here for more details about this article) |
8/70. Primary primitive peripheral neuroectodermal tumor of the prostate. Immunophenotypic and molecular study of a case.A case of primitive peripheral neuroectodermal tumor arising in the prostate gland of a 31-year-old man and first diagnosed through a biopsy is reported. Microscopically, the tumor was made up of solid nests and sheets of small round cells, and it was difficult to distinguish the neoplasm from other small round cell tumors, such as small cell carcinoma, rhabdomyosarcoma, or malignant lymphoma. Immunohistochemically, the tumor cells showed immunoreactivity for CD99, vimentin, neuron-specific enolase, and synaptophysin. The neoplasm was excised by a radical surgical procedure preceded by chemotherapy and radiation therapy. The morphologic diagnosis of the prostatectomy specimen was complemented by molecular analysis performed on viable microdissected tissue obtained from formalin-fixed, paraffin-embedded tumor sections. polymerase chain reaction and sequencing assessment showed the presence of EWS/FLI1 type 2 chimeric transcript, confirming the diagnosis of peripheral primitive neuroectodermal tumor. To our knowledge, this is the first description of a primary peripheral primitive neuroectodermal tumor in the prostate gland.- - - - - - - - - - ranking = 2keywords = neoplasm (Clic here for more details about this article) |
9/70. Malignant peripheral primitive neuroectodermal tumor-peripheral neuroepithelioma of the head and neck: a clinicopathologic study of five cases and review of the literature.BACKGROUND: The term primitive neuroectodermal tumor (PNET) encompasses a number of neoplasms of common neuroectodermal origin, but of variable clinical, histopathologic, ultrastructural, and molecular characteristics. Here, we focus on one particular member of the PNET family, the malignant peripheral PNET (pPNET) or peripheral neuroepithelioma of head and neck. methods: Five patients diagnosed with malignant pPNET-peripheral neuroepithelioma of head and neck were included in the study. All existing literature was reviewed. RESULTS: The diagnosis of malignant pPNET-peripheral neuroepithelioma of the head and neck was confirmed in all five cases. All patients are alive after treatment with a combination of therapeutic modalities; only one patient had metastatic disease develop. A literature review revealed another 38 reported cases. CONCLUSIONS: Malignant pPNET-peripheral neuroepithelioma should be included in the differential diagnosis of small, round, blue cell tumors of head and neck. A combination of multiple diagnostic modalities is essential for correct diagnosis, and multimodality treatment offers the best outcome.- - - - - - - - - - ranking = 1keywords = neoplasm (Clic here for more details about this article) |
10/70. Primitive neuroectodermal tumor of the kidney. A report of two cases diagnosed by fine needle aspiration cytology.BACKGROUND: Primitive neurocetodermal tumors (PNETs) constitute a family of neoplasms of presumed neuroectrodermal origin most often presenting as bone or soft tissue masses. There are very few reported cases of PNET of the kidney and none diagnosed by fine needle aspiration cytology (FNAC), to the best of our knowledge, in the world literature. We present two cases of renal PNET diagnosed on cytology. CASES: Two patients with renal masses were diagnosed as having PNET on FNAC. Cytologically the tumors showed a dispersed population of malignant small round cells with focal rosette formation and perivascular arrangement of tumor cells. immunohistochemistry on the cell blocks in both cases showed strong membrane positivity for CD99 (MIC2). Cytogenetic studies in both cases showed the characteristic t(11;22)(q24;q12) translocation, with additional chromosomal abnormalities in case 2. CONCLUSION: PNET of the kidney is a distinct entity and can be diagnosed on fine needle aspiration smears and confirmed with immunohistochemistry and cytogenetic studies. A diagnosis of PNET must be included in the differential diagnosis of renal masses in adolescents and young adults.- - - - - - - - - - ranking = 1keywords = neoplasm (Clic here for more details about this article) |
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