Immunohistochemical and Ultrastructural Investigation of Neural Differentiation in Ewing Sarcoma/PNET of Bone and Soft Tissues

The authors evaluated the role of immunohistochemistry and electron microscopy in defining neural differentiation in 28 cases of Ewing sarcoma/ PNET. The panel of primary antibodies used included vimentin, MIC-2, NSE, S-100 protein, leu7, neurofilaments, GFAP, and chromogranin A. Cases were considered undifferentiated when neural markers were absent, poorly differentiated if one neural marker was present, and well differentiated if two or more markers were observed. Cases were also evaluated for the presence of cytoplasmic processes, microtubules, and neurosecretory granules as ultrastructural features of neural differentiation: the tumor was classified as well differentiated if two of these features were present; and poorly differentiated if one was evident; all other cases were considered undifferentiated. According to immunohistochemistry, 10 cases (35.7%) were undifferentiated, 12 cases (42.9%) were poorly differentiated, and 6 (21.4%) were well differentiated. According to the ultrastructural analysis, 10 tumors were undifferentiated (35.7%), 14 poorly differentiated (50%), and 4 well differentiated (14.3%). The overall concordance between the two techniques was low (35.7%), and both modalities were concordant in classifying only 1 well-differentiated, 5 poorly differentiated, and 4 undifferentiated tumors. In conclusion, the authors suggest that investigations devoted to test the prognostic significance of neural differentiation in these neoplasms should employ both immunohistochemistry and electron microscopy, separately and in combination, to assess what is the most effective choice for predicting the clinical course.     

Ultrastructure of the Ewing's sarcoma family of tumors

Specimens of 47 tumors diagnosed by routine light microscopy as Ewing's sarcoma of bone, and 5 similar soft tissue tumors (extraskeletal Ewing's sarcomas), were examined by transmission electron microscopy. Immunohistochemical stains were performed on all the tumors, and pre-therapy and post-therapy specimens from 5 of the patients were compared. Cell and nuclear areas were assessed in 41 cases by cytomorphometry by using low-magnification electron micrographs. DNA ploidy was determined by static cytometry on 51 of the tumors. None of the methods revealed differences between the bone and soft tissue tumors. The ultrastructural spectrum extended imperceptibly from the typical forms to markedly irregular variants, and was much broader than could be anticipated from the light microscopy. Neural features were observed but they were not common. Comparison of the Ewing's sarcomas with a group of other small round cell tumors (rhabdomyosarcoma, neuroblastoma, small cell carcinoma) using the same techniques showed that they have similar cell and nuclear areas despite the obvious differences in their immunophenotypes and ultrastructure. The collective findings are in keeping with the currently favored view that Ewing's sarcoma and peripheral primitive neuro-ectodermal tumor are the extremes in a morphologic continuum within which neural differentiation ranges from absent to prominent.     

Colonic Ewing Sarcoma/PNET associated with liver metastases: A systematic review and case report

Ewing Sarcoma is a highly lethal undifferentiated tumor of bone. ES is a small round cell tumor with etiological and characteristic chromosomal translocations between TET/FET (TLS/FUS, EWSR1, and TAF15) and ETS (E26 transformation-specific) family genes. Generally, therapeutic approach for metastatic Ewing Sarcoma includes both local (surgery and radiotherapy) and systemic (chemotherapy) disease control with an overall cure rate of 20%. For extra-osseous tumors, the most common primary sites of disease are trunk, extremities, head and neck, retroperitoneum. Among other sites, Ewing Sarcoma/PNET may also rarely arise in colon and rectum. Even if colonic Ewing Sarcoma/PNET have been previously reported in 5 cases, none of those reports came from right side of the colon. In this article, we report the first case of right-sided Ewing Sarcoma with synchronous liver metastases completely responding to first line chemotherapy. Furthermore, we provide a systematic qualitative review of the current literature on adult colorectal Ewing Sarcoma using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).     

Primary Ewing sarcoma/PNET of the kidney: fine-needle aspiration, histology, and dual color break apart FISH Assay

A 34-year-old previously healthy Hispanic man presented with lower back pain. CT scan revealed an 8-cm space-occupying lesion in the superior pole of the left kidney with numerous small lytic lesions in the skull, vertebrae, ribs, and pelvic bones. CT-guided fine-needle aspiration biopsy revealed a high-grade primitive small round cell tumor with the tumor cells being strongly positive for CD99 and vimentin. The patient subsequently underwent a left nephrectomy. Fluorescence in situ hybridization analysis using a DNA probe for the Ewing Sarcoma breakpoint region 1 (EWSR1) on chromosome 22g12 revealed a rearrangement of the EWSR1 locus. The diagnosis of primary Ewing sarcoma/primitive neuroectodermal tumor of the kidney was established.     

Brenner Tumor of the Ovary: A Comparative Immunohistochemical and Ultrastructural Study With Transitional Cell Carcinoma of the Bladder

Because of a fancied light microscopic resemblance to transitional epithelium (urothelium), Brenner tumor (BT) of the ovary is commonly described as a transitional cell neoplasm. An inability to detect a great deal of similarity between the two at the ultrastructural level prompted this electron microscopic study comparing 3 benign Brenner tumors with normal urothelium and 6 transitional cell carcinomas (TCC) of varying histologic grade from the urinary bladder. To complement the ultrastructural observations, the immunophenotype of 8 benign BTs was evaluated together with that of 12 TCCs of the bladder using antibodies to thrombomodulin (TM), cytokeratin 20, cytokeratin 7, and carcinoembryonic antigen (CEA), all of which havebeen shown to react with TCCs of urothelial origin. At the ultrastructural level, there was only limited evidence of a morphologic likeness between the epithelial cells of BTs and those of the benign or neoplastic urothelium. The immunophenotype of the two tumors also differed significantly in that there was no reactivity for TM or cytokeratin 20 in the BTs, while these markers were expressed in the TCCs. Both BTs and TCCs were positive for cytokeratin 7 and may express CEA.     

Malignant mesenchymal tumors of the ovary in three cases: Histology, immunohistochemistry, and ultrastructural observations

Primary ovarian sarcoma is a rare neoplasm. The diagnosis sometimes becomes difficult by light microscopic examination alone because of the rarity and heterogeneity of these tumors. Immunohistochemical and ultrastructural studies are very useful for diagnosis. Here, we describe two cases of ovarian sarcomas: fibrosarcoma and leiomyosarcoma, and a case of carcinosarcoma (homologous malignant mixed müllerian tumor). In addition to histological findings, immunohistochemical and ultrastructural observation was undertaken to make a final diagnosis. Clinical outcome was variable in the three cases. It was unlikely to be related to the disease stage or treatment, such as surgical excision or anticancer drugs, whereas the mitotic index may be an important prognostic indicator in ovarian sarcomas.Fibrosarcoma was presented in the 19th Annual Meeting of the Clinical Electron Microscopy Society of Japan, Tokyo, on September 17, 1987. Leiomyosarcoma and carcinosarcoma were presented in the 26th Annual Meeting of the Clinical Electron Microscopy Society of Japan. Kochi, on October 5, 1994.     

Submicroscopic and Immunohistochemical Profile of Surface Osteosarcomas

While the analysis of the clinical, radiologic, and histopathologic features of surface osteosarcomas has been the subject of several papers, identification of the phenotypic features of these tumors has so far received little attention. The aim of the present study was to characterize the neoplastic cells of surface osteosarcomas using an ultrastructural and immunohistochemical approach. Glutaraldehyde-fixed, epoxy resin-embedded archival pieces of tissue from 8 surface osteosarcomas (4 parosteal low-grade osteosarcomas, 3 dedifferentiated parosteal osteosarcomas, 1 periosteal osteosarcoma) were investigated using transmission electron microscopy. Sections of formalin-fixed, paraffin-embedded tumor specimens were employed for the immunohistochemical analysis of osteonectin and osteocalcin, two markers of cells of osteoblastic lineage, and alpha -smooth muscle actin and muscle specific actin. By electron microscopy, the tumors were composed of a mixture of neoplastic cells with varied differentiation, i.e., osteoblast-like, fibroblast-like, myofibroblast-like, and chondroblast-like. The latter were particularly abundant in the periosteal osteosarcoma. Osteocalcin expression was detected in the cytoplasm of neoplastic cells in 6 cases (66.6%), while osteonectin was expressed at least focally in all cases. The expression of the noncollagenous bone proteins was higher in low-grade osteosarcomas than in dedifferentiated osteosarcomas. alpha -Smooth muscle actin and muscle-specific actin expression were detected in 4 (44.4%) and 5 (55.5%) cases respectively, and the distribution was similar in both low-grade and dedifferentiated lesions. The results do not confirm previous observations regarding the prevalence of a specific cellular phenotype in surface osteosarcomas. Further, the myofibroblast-like cells that are present in variable numbers in these tumors are probably modified osteoblasts, since they co-express actin, osteonectin, and osteocalcin.     

Submicroscopic and Immunohistochemical Profile of Surface Osteosarcomas

While the analysis of the clinical, radiologic, and histopathologic features of surface osteosarcomas has been the subject of several papers, identification of the phenotypic features of these tumors has so far received little attention. The aim of the present study was to characterize the neoplastic cells of surface osteosarcomas using an ultrastructural and immunohistochemical approach. Glutaraldehyde-fixed, epoxy resin-embedded archival pieces of tissue from 8 surface osteosarcomas (4 parosteal low-grade osteosarcomas, 3 dedifferentiated parosteal osteosarcomas, 1 periosteal osteosarcoma) were investigated using transmission electron microscopy. Sections of formalin-fixed, paraffin-embedded tumor specimens were employed for the immunohistochemical analysis of osteonectin and osteocalcin, two markers of cells of osteoblastic lineage, and alpha -smooth muscle actin and muscle specific actin. By electron microscopy, the tumors were composed of a mixture of neoplastic cells with varied differentiation, i.e., osteoblast-like, fibroblast-like, myofibroblast-like, and chondroblast-like. The latter were particularly abundant in the periosteal osteosarcoma. Osteocalcin expression was detected in the cytoplasm of neoplastic cells in 6 cases (66.6%), while osteonectin was expressed at least focally in all cases. The expression of the noncollagenous bone proteins was higher in low-grade osteosarcomas than in dedifferentiated osteosarcomas. alpha -Smooth muscle actin and muscle-specific actin expression were detected in 4 (44.4%) and 5 (55.5%) cases respectively, and the distribution was similar in both low-grade and dedifferentiated lesions. The results do not confirm previous observations regarding the prevalence of a specific cellular phenotype in surface osteosarcomas. Further, the myofibroblast-like cells that are present in variable numbers in these tumors are probably modified osteoblasts, since they co-express actin, osteonectin, and osteocalcin.     

骨尤因肉瘤中分化抑制因子Id2的表达及意义

目的探讨分化抑制因子2(inhibitor of differentiation 2,Id2)在骨尤因肉瘤中的表达及其与细胞周期相关蛋白的关系。方法采用免疫组化En Vision法检测45例骨原发尤因肉瘤中Id2、c-Myc、Cyclin D1、p53、p16及p27的表达,分析Id2与骨尤因肉瘤临床病理特征及细胞周期蛋白表达的相关性。结果 45例骨尤因肉瘤中,Id2阳性率为88.9%,其中15例为强阳性(33.3%);c-Myc、Cyclin D1、p53、p16、p27阳性率分别为66.7%、71.1%、20.0%、35.6%、28.9%。Id2强阳性与p27表达呈负相关关系(P<0.05)。获得随访24例,其中16例死亡,1例肺转移,7例无瘤生存,死亡及肺转移病例中Id2强阳性占41.2%,明显高于无进展存活病例14.3%。结论 Id2在骨尤因肉瘤中广泛表达,其强阳性与细胞周期蛋白p27表达相关,Id2/p27通路可能在尤因肉瘤的发生、发展中起重要作用。Id2强阳性患者可能预后较差。     

Ewing sarcoma/primitive neuroectodermal tumor of the kidney: a case report. Diagnosed by immunohistochemistry and molecular analysis

BACKGROUND: Ewing sarcoma/primitive neuroectodermal tumor (EWS/PNET) of the kidney is a rare and aggressive tumor. It has a rapid clinical progression with early metastasis and death. Few cases with documented t(11;22) have been reported in the literature. CASE PRESENTATION: We report a case of EWS/PNET of the kidney in a 26-year-old woman with widespread metastasis at initial presentation. The tumor cells showed strong expression for CD99 and FLI-1 monoclonal antibodies and polyclonal antibodies and were negative for WT1 and numerous other markers. The diagnosis was subsequently confirmed by demonstrating t(11;22)(q24;q12) using cytogenetic karyotyping and fluorescence in situ hybridization. CONCLUSIONS: Due to the different prognosis and management between EWS/PNET and other primary renal neoplasms with similar morphology, a histopathologic diagnosis with extreme accuracy should be made. Cytogenetic analysis is an important supportive tool to immunohistochemistry in making the final diagnosis.     

Hyalinizing spindle cell tumor with giant rosettes and low-grade fibromyxoid sarcoma: an immunohistochemical and ultrastructural comparative investigation

Hyalinizing spindle cell tumor with giant rosettes (HSCTGR) and low-grade fibromyxoid sarcoma (LGFMS) are 2 variants of fibrosarcoma, which share several clinicopathologic features. This study compares the light microscopic, immunohistochemical, and ultrastructural features of 2 examples of HSCTGR and 3 of LGFMS to determine the degree of overlap of these 2 tumors. HSCTGR were composed of bland spindle cells within hyalinized to myxoid stroma. Scattered throughout the lesions were characteristic rosette-like structures, formed by a central collagenous core surrounded by spindled neoplastic cells. LGFMS consisted of a mixture of fibrous and myxoid areas, composed of fibroblast-like cells arranged in a swirling, whorled growth pattern. Immunohistochemical analysis showed diffuse positivity for vimentin in all cases, while few scattered tumor cells stained for CD57, CD34, factor XIIIA, and actin. The extracellular matrix showed intense positivity for type IV collagen, laminin, and fibronectin, with the exception of myxoid areas of LGFMS and the central core of the giant rosettes in HSCTGR. Ultrastructurally, both tumor types were composed of cells with the features of fibroblasts, embedded in a collagenous stroma with irregular deposits of amorphous basal lamina-like substance. In conclusion, HSCTGR and LGFMS share similar immunophenotypic and ultrastructural features, and together with other fibrosing fibrosarcomas, like sclerosing epithelioid fibrosarcoma, may constitute a subset of fibrosarcomas formed by fibroblasts capable of producing large amounts of basal lamina-like material.     

Intercellular junctions, apical differentiation, and infiltrative features in colon cancer: an ultrastructural study. The Colon Cancer Team at IMAS

Changes in the structure and number of cell junctions have been related to the infiltrative and metastatic potential of tumor cells. Apparently, the loss of cell adhesion should be coordinated with significant changes in the apical and basal cell domains. The authors have performed a sequential ultrastructural study of cells in the superficial, middle, and deep regions of well- and moderately differentiated colon adenocarcinomas. This was to investigate the differencesin the organization of different membrane domains among tumor cells in the in situ areas, the advancing, infiltrative edge of the tumors, and the infiltrating zones between these two extreme zones. The results of the study suggest that the organization of these domains is not strictly coordinated, and that, for each infiltration level, both a settling and an infiltrating cell population can be found. These findings could explain the fact that apparently well-differentiated tumors are able to seed distant tissues with individual cells, rather than with well-differentiated glandular aggregates that would hardly be able to reach the vessel lumina without significantly modifying their organization.     

神经干细胞分化调控机制的研究进展

神经干细胞（NSCs）是一类具有自我更新和多方向分化潜能的干细胞,可以分化为神经元,星形胶质细胞和少突胶质细胞。自从1992年Reynolds等从小鼠纹状体中分离到神经干细胞之后,相关的研究已经取得了很大的进展。然而由于中枢神经系统内神经干细胞数量较少,而神经系统损伤后移植的外源的神经干细胞大多分化为神经胶质细胞,进而形成瘢痕组织,限制了神经系统的恢复。因此,如何实现神经干细胞的定向诱导分化成为当前该领域的核心问题。     

Immunohistochemical and ultrastructural investigation on cutaneous neuroendocrine carcinoma: report of a case and review of the literature

We report a tumor in an 80-year-old man that was difficult to distinguish from other tumors, i.e., small cell carcinoma of the lung, PNET/Ewing tumor, malignant lymphoma, or malignant melanoma (amelanotic), and which was finally identified as cutaneous neuroendocrine carcinoma using immunohistochemical and ultrastructural methods. Autopsy did not show any tumors in the lungs, excluding the possibility of small cell carcinoma of the lung. Immunohistochemistry tests gave negative results for LCA, UCHL-1, CD3, and CD20, thereby excluding malignant lymphoma, and the negative results for S-100 protein and HMB-45 ruled out malignant melanoma. The possibility of PNET/Ewing sarcoma was also excluded because of negativity for CD99. In addition, the ultramicrostructure showed intercellular junctional complexes and neuroendocrine granules, indicating that the tumor had characteristics of both epithelial and neuroendocrine tissues. We therefore diagnosed the primary carcinoma of the skin as cutaneous neuroendocrine carcinoma.     

Subcutaneous Ewing sarcoma/PNET as a second cancer in a previously irradiated young patient. an uncommon type of post-irradiation soft tissue sarcoma

Soft tissue sarcomas account for a small proportion of second cancers, with an estimated frequency of < 10%. The most common histologic type of soft tissue sarcomas as second cancers include mostly high-grade sarcomas, such as rhabdomyosarcoma, malignant peripheral nerve sheath tumour, fibrosarcoma, leiomyosarcoma, synovial sarcoma, alveolar soft part sarcoma and Ewing sarcoma/primitive neuroectodermal tumour (PNET). We report a case of superficial soft tissue Ewing sarcoma/PNET as a second cancer in a young patient previously treated for Hodgkin's disease (HD). To the best of our knowledge and based on a literature search, this is the first reported case of post-irradiation soft tissue Ewing sarcoma/PNET as a second cancer arising in the same area irradiated for cure of HD.     

Duodenal Periampullary Gangliocytic Paraganglioma: Report of Two Cases with Immunohistochemical and Ultrastructural Study

We report two cases of Gangliocytic Paraganglioma (GP) of the ampulla of Vater occurring in a 63-year-old and a 34-year-old individual. The patients were both admitted for a long history of intermittent gastrointestinal bleeding and abdominal discomfort, with no other symptoms. At endoscopy, the GP appeared as a polypoid, ulcerated mass in the ampullar region, measuring 2.5x1.8 and 2 cm, respectively. Microscopically, the tumors showed similar features and were composed of epithelial cells (more than 50%), spindle cells, and ganglion-like cells. The epithelial cells showed clear cytoplasm and formed nests (zellballen or paraganglioma-like groups), and less frequently, cords (carcinoid-like), extending to mucosa and submucosa. Ganglion cells were sparse, constantly associated with the spindle cells. Both epithelial and ganglion cells were synaptophysin, chromogranin A, and anti-neurofilament immunoreactive. The spindle cells were all S-100 positive. Ultrastructural studies revealed dark and light cells, rare elongated cellular processes, secretory granules, and fine fibrils resembling neurofilaments. The histogenesis of GP is still a matter of debate, however its neoplastic nature is supported by the occasionally reported malignant evolution.     

Erk1/2 promotes proliferation and inhibits neuronal differentiation of neural stem cells

Neural stem cells (NSCs) are in a complex niche in which cell-extrinsic cues and cell-intrinsic genetic mechanisms in chorus mediate their cellular processes such as self-renewal and differentiation. In this study, we found that inactivation of Erk1/2 with U0126 in NSCs significantly promoted neuronal differentiation and inhibited proliferation. Sustained Erk1/2 inactivity was required in this process. We also found that nerve growth factor (NGF) and collagen could promote the proliferation and inhibit neuronal differentiation by activating phosphorylation of Erk1/2. Cell-cycle regulators such as cyclin-dependent kinase 2 (Cdk2), Cyclin D1 and Hes1 mediated the effect of Erk on NSCs proliferation and differentiation. Our results showed that Erk1/2 played an important role in the interplay between cell-extrinsic cues and cell-intrinsic genetic mechanisms in neural stem cell biology.     

儿童腺泡状软组织肉瘤13例临床病理学特征

目的探讨儿童腺泡状软组织肉瘤(alveolar soft part sarcoma,ASPS)的临床病理、分子遗传学特点、诊断及鉴别诊断。方法对北京儿童医院2009年8月至2018年11月13例儿童ASPS病例存档切片行HE染色及组织化学染色[包括过碘酸-雪夫(PAS)染色及淀粉酶消化PAS(D-PAS染色)]。采用免疫组织化学染色检测TFE3、INI1、CD68等的表达,应用荧光原位杂交(FISH)法检测TFE3基因断裂易位情况。结果13例ASPS中,男童4例,女童9例,年龄1岁2个月至13岁8个月,平均7.8岁,5岁以下4例。组织学上,11例肿瘤细胞呈腺泡状、巢状排列,2例肿瘤细胞呈实性、弥漫性生长。瘤细胞胞质嗜酸性,可见明显的空泡现象,核多形性,核仁突出,核分裂象罕见,3例可见血管浸润。免疫组织化学染色TFE3弥漫核阳性,INI1、CD68、波形蛋白阳性,MyoD1、Myogenin、细胞角蛋白、S-100蛋白等均阴性。7例PAS及D-PAS染色显示肿瘤细胞质内均可见紫红色针状或棒状结晶体。9例行FISH检测,均显示TFE3基因断裂易位。结论ASPS为儿童少见软组织肿瘤,肿瘤多位于深部肌肉内,瘤细胞排列成腺泡状或巢状,同时TFE3基因位点发生断裂易位,确定诊断需要结合临床、病理形态、免疫组织化学及基因检测综合考虑。