1/13. Intraoral tumor of Chievitz in a child.Juxtaoral organs known as organs of Chievitz are intramuscular embryonic structures found close to the angle of the mandible near the insertion of the pterygomandibular raphae. They are considered of neuroepithelial origin with no known function. We describe the first tumor of the organ of Chievitz which presented intraorally in a child. Immunohistochemically, the Chievitz nests showed positive reaction for vimentin, cytokeratins, and epithelial membrane antigen and ultrastructurally demonstrated cytoplasmic processes and intermediate filament bundles. These observations, together with light microscopic features, suggest that the epithelial nests of the organ of Chievitz are meningothelial rather than neuroepithelial.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/13. Primary primitive neuroectodermal tumor of the lung: report of two cases.Two cases of primitive neuroectodermal tumor of the lung are reported. The first case is a 41-year-old man with a tumor in the left upper lung, and the second case is a 30-year-old woman with a tumor in the right lower lung. In both cases, the tumors originated in the lung but not in the chest wall. No distant metastasis was detected. In case 1, transcutaneous fine-needle biopsy (TCNB) revealed small round cell proliferation, although bronchoscopic examination showed no abnormal findings. Both the expression of Mic2 protein and t(11;22)(q24;q12) translocation were proved in the tumor cells. The tumor cells were positive for periodic acid-Schiff (PAS), neuron-specific enolase (NSE), and vimentin, but negative for Leu7, chromogranin a, and pro-gastrin-releasing peptide (ProGRP). In case 2, bronchoscopic examination showed only compressive change in right lower lobe bronchi. TCNB revealed small round tumor cells expressing Mic2 protein. The tumor cells were negative for leukocyte common antigen, S100 protein, pankeratin, chromogranin a, and desmin, but weakly positive for NSE and moderately positive for Ki-67 (MIB1). Both patients were successfully treated by the combination of surgical resection and chemotherapy, and are alive with no sign of recurrence for approximately 22 months in case 1 and 16 months in case 2.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
3/13. 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 = antigen (Clic here for more details about this article) |
4/13. Ewing's sarcoma/peripheral primitive neuroectodermal tumor (pPNET) arising in the omentum as a multilocular cyst with intracystic hemorrhage.A rare case of Ewing's sarcoma/peripheral primitive neuroectodermal tumor arising in the greater omentum in a 41-year-old man is reported. The patient presented with a hemorrhagic mesenteric cyst that was disclosed by the results of an abdominal echogram, a computed tomography scan, and magnetic resonance imaging. A laparotomy showed a multilocular cyst with intra-cystic hemorrhage. Histologically, the tumor wall consisted of sheets of small round cells separated by thick desmoplastic stroma. Rosette formations or ribbon-like cell arrangements were absent. Further pathological examination revealed that the membrane of the tumor cells was positive for MIC-2, and negative for epithelial membrane antigen, cytokeratin, and desmin, which are usually positive in intra-abdominal desmoplastic small round-cell tumors. An EWS/FLI1 fused transcript was detected by reverse transcription-polymerase chain reaction. These findings confirmed the diagnosis of Ewing's sarcoma/peripheral primitive neuroectodermal tumor. The patient died of tumor recurrence 4 months after his first admission. The autopsied tumor tissue exhibited neural differentiation in certain regions. To our knowledge, this is the first case to be reported of Ewing's sarcoma/peripheral primitive neuroectodermal tumor arising in the omentum with unique pathological features and the occurrence of partial neural differentiation during the clinical course. This case pointed out to us, as gastroenterologists, that only thorough examination confirms a definitive diagnosis of small round-cell tumor of the abdomen, it also shows that Ewing's sarcoma/peripheral primitive neuroectodermal tumor should be included in the differential diagnosis of cystic lesions in the omentum.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
5/13. Primitive neuroectodermal tumor of the uterus. A case report.BACKGROUND: Primitive neuroectodermal tumors (PNETs) of the uterus are very rare. Even preoperative curettage specimen morphology does not permit establishing a proper histogenetic diagnosis. CASE: A 16-year-old woman was admitted to the hospital because of metrorrhagia of three months' duration. The curettage specimen was interpreted as poorly differentiated sarcoma. The patient was operated on, and a total abdominal hysterectomy with bilateral salpingo-oophorectomy with omentectomy was performed. Histologically the tumor was composed of uniform, rounded, oval and sometimes spindle shaped cells with a narrow rim of eosinophilic cytoplasm. The cells were positive for neurogenic marker protein gene product, neuron-specific enolase and Ewing's sarcoma-related HBA-71. All cells were uniformly negative for Ber EP4 monoclonal antibody recognizing an epithelium-specific surface antigen. A diagnosis of PNET was rendered. The patient received combined therapy, external radiation to the pelvis and chemotherapy. Four years later she was alive, without signs of recurrent tumor. CONCLUSION: In spite of the generally recognized aggressive behavior of PNET, it can have a long disease-free survival rate when appropriately treated.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
6/13. Two malignant peripheral primitive neuroepithelial tumor cell lines established from consecutive samples of one patient: characterization and cytogenetic analysis.A 6-year-old girl presented with a tumor of the right shoulder involving bone, adjacent soft tissue, and regional lymph nodes. The conventional histologic diagnosis was ambiguous, initially suggesting lymphoma. After relapse on lymphoma therapy, reevaluation with additional multiple diagnostic techniques performed on the biopsy tissue and on two cell lines derived from the biopsies established the diagnosis of a primitive neuroepithelial tumor of bone and soft tissue. This was strongly supported by 1) focal rosette formation by the tumor cells and positive immunostaining for neuron-specific enolase and synaptophysin, with absent staining for leukocyte common antigen; 2) at the ultrastructural level, formation of cellular processes containing microtubules, a paucity of neurosecretory granules, absence of synaptic junctions, formation of long "intermediate" junctions between cells, and, in culture, widespread development of rosettes; 3) marked surface positivity to W 6/32 and negativity to HSAN 1.2 antibodies; and 4) elevated expression of MYC and lack of overexpression of MYCN oncogenes. Numerical and structural abnormalities were present in the karyotype, but the expected t(11;22)(q24;q12) was not present in the tumor-involved marrow or in either of the established tumor cell lines, although there was an interstitial deletion of 11q involving breakpoints in q21 and q23.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
7/13. Olfactory neuroblastoma: clinicopathologic and immunohistochemical characterization of four representative cases.Olfactory neuroblastomas are rare tumors whose clinical prognosis is not predictable by assessment of initial stage or grade. The pathologic diagnosis is often difficult because of the wide range of the patient's age and histologies. In this report, we document that the diagnosis of olfactory neuroblastoma can be clarified by immunohistochemical demonstration of a unique antigenic profile that can be obtained in routinely processed biopsies. We describe four cases of olfactory neuroblastoma diagnosed and treated from 1979 to 1989, each confirmed by immunohistology. One of our patients was misdiagnosed twice at an outside institution, first as having nasopharyngeal carcinoma and then as having small-cell, undifferentiated "oat cell" carcinoma. Despite accurate tumor diagnosis and appropriate therapy, we found that there was no apparent correlation of clinical outcome with Kadish clinical stage or histologic grade of tumor.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
8/13. Congenital primitive neuroectodermal tumor with epithelial and glial differentiation. An ultrastructural and immunohistochemical study.A congenital primitive neuroectodermal tumor associated with epithelial and glial elements is described. This soft-tissue tumor present on the right temple of a newborn boy consisted mainly of small round cells of the primitive neuroepithelial type, occasionally forming rosettes. The other components were focal glandular structures producing mucin, and aggregates of epithelioid cells bearing clear cytoplasm, both being distributed throughout the entire tumor. Additional glandular and clear cell components were strongly positive for various epithelial markers, such as carcinoembryonic antigen, epithelial membrane antigen, and cytokeratin. epithelioid cells were also positive for neuron-specific enolase and S100 protein. Glial differentiation was evidenced in some of the epithelioid cells by localization of cytoplasmic glial fibrillary acidic protein. These findings suggest that this tumor derives from a remnant of a neural crest, and the possibility of a special type of peripheral primitive neuroectodermal tumor is considered.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
9/13. Peripheral neuroepithelioma in childhood. Immunohistochemical demonstration of epithelial differentiation.Peripheral neuroepithelioma arising from the chest wall of a 4-year-old girl is described. She died of local recurrence 15 months after surgery. light- and electron-microscopic as well as immunohistochemical findings confirmed the neuroectodermal nature of the tumor. A distinctive histologic feature was the presence of clustered epitheliallike cells, which immunohistochemically stained positive for both keratin and carcinoembryonic antigen. The epithelial nature of these peculiar cells is presented.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
10/13. Monoclonal antibodies to intermediate filament proteins: diagnostic specificity in orbital pathology.intermediate filaments derived from different cell types are antigenically distinct. Monoclonal antibodies to human intermediate filament proteins can, therefore, be used as tissue-specific reagents capable of distinguishing cell type in poorly differentiated neoplasms. We report a case demonstrating the specificity of antiintermediate filament protein antibodies in establishing a difficult orbital diagnosis of esthesioneuroblastoma.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
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