Dedifferentiated chondrosarcoma. An ultrastructural study

The light and electron microscopic features of a well-differentiated chondrosarcoma with dedifferentiated foci (dedifferentiated chondrosarcoma) is presented. Ultrastructurally, the cells of the dedifferentiated portion were embedded in a matrix containing numerous short bundles of collagen fibers; these cells showed dilated rough endoplasmic reticulum containing stippled material as well as poorly formed cell junctions and resembled the cells in the cartilaginous component. These findings contrast with those reported previously.     

Characterization of type I collagen synthesis and maturation in uterine carcinosarcomas.

BACKGROUND: Epithelial malignancies often induce an enhanced expression of interstitial collagens in the fibroblasts within the tumor tissue and the surrounding non-neoplastic stroma. In uterine carcinosarcomas (malignant mixed müllerian tumors [MMMTs]) both the stroma and the epithelium are malignant. METHODS: In this investigation, both in situ hybridization and immunohistochemical staining were applied with two different antibodies that were capable of distinguishing between newly synthesized and mature, trivalently cross-linked Type I collagen to define Type I procollagen mRNA expression and the synthesis and maturation of the corresponding protein in MMMTs. RESULTS: In the better differentiated parts of these tumors, in which anticytokeratins stained only clearly carcinomatous cells, Type I procollagen mRNA expression was limited to stromal fibroblasts; mature Type I collagen bundles were abundant and regular. In poorly differentiated areas, in which anticytokeratins stained only a few individual cells, Type I procollagen mRNA was expressed peculiarly by three morphologically different cell types. In addition to benign mesenchymal cells, Type I procollagen mRNA was present in atypical epithelial and mesenchymal cells. In these tumors, the collagen bundles close to the malignant cells were comprised of newly synthesized Type I collagen, with only little evidence of the presence of mature, fully cross-linked collagen. CONCLUSIONS: These results strongly suggest that the undifferentiated cells of MMMTs are capable of producing their own stroma with irregularly arranged collagen bundles.     

p53 expression in dedifferentiated chondrosarcoma

Background. p53 acts as a tumor suppressor gene because of to its negative control of the cell cycle and its central role in programmed cell death. It frequently is mutated, as observed in a variety of human neoplasms. The mutations inhibit tumor-suppressor activities of p53, which may gain a new function of tumor promotion. In this study, p53 was investigated in various components of dedifferentiated chondrosarcoma and correlated with their proliferative activities. Methods. Immunohistochemical assays for p53, Ki-67, and proliferating cell nuclear antigen (PCNA) were used in a series of eight dedifferentiated chondrosarcomas of bone. The cartilaginous component was low grade (Grade I-II) in five cases. It was predominantly low grade with foci of a high grade (Grade III) chondrosarcoma in the remaining three cases. The noncartilaginous (de-differentiated) high grade component consisted of malignant fibrous histiocytoma in five cases and osteosarcoma in three. Results. Regardless of the histological type, diffuse strong nuclear staining for p53 occurred in the high grade noncartilaginous component of all eight of the tumors. The low grade cartilaginous component of six cases was negative for p53, with focal weak staining in the two remaining cases. The high grade cartilaginous component showed strong positive staining for this protein in all three cases. Ki-67 and PCNA expression were similar to that of p53. Conclusions. The percentage of p53 positive staining roughly was parallel to the proliferating fraction of cells in various components of dedifferentiated chondrosarcoma. Moreover, p53 overexpression was consistently present in the high grade noncartilaginous (dedifferentiated) component of the tumor and was accompanied by increased proliferative activity. Cancer 1995; 76:223-7.     

Runx2 在去分化软骨肉瘤细胞系中的表达及其意义

 目的　检测Runx2基因在去分化软骨肉瘤中与普通软骨肉瘤中的表达差异,进一步明确Runx2在去分化软骨肉瘤发生发展中的意义。方法　培养去分化软骨肉瘤细胞系NDCS-1及普通软骨肉瘤细胞系SW1353,提取细胞mRNA及总蛋白,RT-PCR、Western blotting及细胞免疫学检测Runx2在细胞系中的表达,之后对病理证实的去分化软骨肉瘤进行免疫组织化学染色,检测其在组织中的表达。结果　RT-PCR和Western blotting结果显示与普通软骨肉瘤细胞系SW1353相比,Runx2在去分化软骨肉瘤细胞系NDCS-1中高表达;免疫组织化学结果显示与普通软骨肉瘤成分相比,Runx2 在组织中的高度恶性成分中高表达。结论　Runx2在去分化软骨肉瘤中的高表达参与了去分化软骨肉瘤的发生和发展。     

Extraskeletal myxoid chondrosarcoma in young children

Two extraskeletal myxoid chondrosarcomas with a solid soft tissue mass occurred on the right upper arm of a 4-year-old boy and on the chest wall of a 1-year-old boy. Microscopically, both tumors were characterized by lobular configuration and were sparsely cellular with a background of myxoid matrix. The cells were small and round, and appeared undifferentiated, sometimes with a narrow eosinophilic cytoplasm. They grew in nests or strands and sometimes in a single file. They were strongly positive for S-100 protein and vimentin. Ultrastructural features suggested that the cells had a poorly differentiated mesenchymal nature with chondrocytic differentiation. These are the sixth and seventh reported cases of extraskeletal myxoid chondrosarcoma occurring in children. There are definite differences between this tumor with immature features and the extraskeletal myxoid chondrosarcoma in adults. Problems of differential diagnoses from other small round cell sarcomas also are discussed.     

Mesenchymal chondrosarcoma--report of 4 cases

This paper reports 4 cases of mesenchymal chondrosarcoma, 1 case in the retroperitoneum, 1 the left mandible, 1 right thoracic wall and 1 right thigh. 2 males and 2 females. The age ranged from 18 to 42 with an average of 29 years. In this series, 3 patients are still alive after operation and one died one year postoperatively. Microscopic examination: the tumor was made up not only of undifferentiated mesenchymal cells, but also of well-differentiated cartilaginous islands and hemangiopericytomalike lesions. Transitions between the undifferentiated small cells and neighbouring chondrocytes or chondroid matrix and collagenous fibers can be found microscopically in all cases. The authors emphasize that collagenous fibers between the undifferentiated cells play an important role in the formation of cartilaginous islands. The differential diagnosis of this disease is discussed.     

15例骨和软组织内间叶性软骨肉瘤临床病理分析

目的 探讨原发间叶性软骨肉瘤的临床特点、诊断和鉴别诊断依据。方法 复习本院15例骨及软组织原发问叶性软骨肉瘤的临床资料和病理学特征（包括对HE染色、免疫组化染色切片的观察分析），对14例行密切随访。结果 10年内15例间叶性软骨肉瘤占同期软骨肉瘤总数的9．4％，占小细胞恶性肿瘤的0．3％，占全部骨肿瘤的7．4％。患者年龄14～70岁，平均42岁。86％的患者存11-40岁之间，无明显性别差异。其中骨内发病13例，软组织内原发肿瘤2例。2例有外伤史。诊断初期多中心性发病者5例，患者多主诉局部疼痛伴肿胀。影像学特征与普通型软骨肉瘤相似，表现为伴有点状钙化的大片溶骨性破坏。组织学表现通常具有双相性，表现为间变的未分化间叶性小细胞与分化较好的分叶状肿瘤性软骨及软骨样基质并存。两种组织之间界限较清晰，移行区可见肿瘤细胞成软骨现象。免疫组织化学显示小细胞区CD99阳性，CollagenII在小细胞区和软骨区均阳性，部分病例CgA、Ki-67、P53有阳性表达，Syn在少数病例有阳性表达。本组患者最长在确诊后7年内死亡，最短在9个月内死亡，其中2例70岁以上的患者均在2年内死于肿瘤转移。结论 间叶性软骨肉瘤少见且预后差。虽然具有典型组织学特征，其诊断和鉴别诊断仍很困难。特别是在穿刺标本中，未穿到软骨性成分时与其他小细胞恶性肿瘤鉴别困难，未穿到小细胞成分时与其他类型软骨肉瘤鉴别困难。诊断中除仔细观察HE和免疫组化染色切片外，还需密切结合临床资料和影像学特征。     

Prognostic relevance of cell biologic and biochemical features in conventional chondrosarcomas

BACKGROUND: Conventional chondrosarcoma is the second most common malignant solid tumor of bone, and its management still poses a challenge for the orthopedic surgeon. Currently, tumor grade is the only parameter of prognostic significance besides stage and, possibly, resection margins. Additional independent prognostic markers therefore would be highly valuable for patient management. METHODS: In the current study, the authors evaluated biologic markers for various chondrocytic phenotypes by histochemical and immunohistochemical technology in a large series of clinically well defined cases of enchondromas and conventional chondrosarcomas, each with at least 5 years of clinical follow-up. RESULTS: The authors' results confirm the strong correlation between clinical behavior and cell differentiation as expressed by marker genes. The phenotypes of the tumor cells are the biologic substrate of the histopathologic appearance of the neoplasms and, thus, the biologic basis for classic tumor grading. Collagen Types II and X, as well as the proteoglycan aggrecan, suggest a mature neoplastic phenotype and good prognosis, i.e., low recurrence rate, rare metastasis, and long survival. Conversely, collagen Type I, together with cell spindling, indicates a transition to a more proliferative, so-called "dedifferentiated" phenotype, which clearly is associated with a poorer prognosis. The changes in cellular phenotypes are accompanied by changes in proliferative activity. Thus, low-grade neoplasms showing mainly mature and terminally differentiated (hypertrophic) chondrocytes display only scant proliferation whereas less differentiated chondrosarcomas with biologically dedifferentiated chondrocytes show significantly higher proliferative activity, a feature that is also highly correlated with prognosis. CONCLUSIONS: These data indicate that molecular markers are to a large extent the biologic basis of the conventional grading, rather than representing independent prognostic markers. The authors' results further indicate that COL1 has significant value in the distinction between enchondromas and low-grade chondrosarcomas including these that are histologically similar. Further understanding of chondrocytic phenotypes will be a promising way to provide new tumor markers for better understanding, diagnosis, and treatment of chondroid neoplasms.     

Establishment and characterization of a new cell line derived from a human chondrosarcoma

A new human cell line, CAL 78, derived from a dedifferentiated chondrosarcoma of the muscle of the thigh has been established in culture. Fibroblastoid morphology, vimentin expression and lack of epithelial antigens are in agreement with mesodermic origin of these cells. The xenograft of CAL 78 cells in nude mouse showed the characteristics of hyaline cartilaginous differentiation. Cytogenetic changes were numerous and complex, all the metaphases were tetraploid and no alterations described by other authors have been found. CAL 78 constitutes an appropriate model to evaluate efficiency of a new therapy for chondrosarcomas. Moreover, this cell line may be used to study some stage of chondrocytic differentiation.     

MYC amplification and polysomy 8 in chondrosarcoma: array comparative genomic hybridization, fluorescent in situ hybridization, and association with outcome.

PURPOSE: To identify recurrent regions of genomic gain or loss in chondrosarcoma in a clinically relevant and statistically valid fashion. Materials and METHODS: Array comparative genomic hybridization (CGH) results of 15 frozen tumor samples of high-grade chondrosarcoma for chromosome 8 are presented. A separate subset of 116 cartilaginous tumors with outcome data was used for validation. RESULTS: Array CGH identified gain at 8q24.12-q24.13, the region of the MYC (c-Myc) oncogene, as a frequent change in high-grade chondrosarcoma. In the validation arm of 116 cartilaginous tumors, MYC was frequently amplified in G2 (15%), G3 (20%), and dedifferentiated (21%) chondrosarcomas. No amplification was identified in samples of enchondroma and grade 1 chondrosarcoma. In samples without MYC amplification, polysomy 8 was a frequent finding in grade 1 (18%), grade 2 (31%), grade 3 (80%), and dedifferentiated (29%) chondrosarcomas, but was not found in any samples of enchondroma. MYC protein expression was identified in all samples with amplification, but was also frequent in the remaining samples without amplification or polysomy 8. Kaplan-Meier survival curves for overall survival showed a statistically significant difference for patients with MYC amplification or polysomy 8 (P = .034). Univariate analysis involving Cox proportional hazards models showed that grade (P = .003), polysomy 8 (P = .045), and MYC amplification (P = .053) correlated with shorter overall survival. By multivariate analysis, grade of chondrosarcoma (P = .026) was the only factor to reach statistical significance. CONCLUSION: MYC amplification and polysomy 8 can be used as markers of prognostic importance in chondrosarcoma. Molecular targeting of MYC expression may have therapeutic potential in the future for subsets of chondrosarcoma.     

Products of cells cultured from gliomas. IV. Extracellular matrix proteins of gliomas

Five primary and 3 established human glioma cell lines were cultured with ascorbate and examined for expression of extracellular matrix components. All lines except C6 expressed collagen as assessed by silver impregnation, immunofluorescence and lectin staining and expressed laminin and fibronectin. None expressed a lectin marker for endothelial cells. Both epithelial and mesenchymal collagens were expressed. While extracellular components of glioma lines resembled those of fibroblasts more closely than other cell types, subtle differences between gliomas and fibroblasts were present. These included more laminin and collagen type-IV antigenic reactivity and more 11-12 nm diameter extracellular fibrils from individual gliomas, and slight differences in spectra of low-molecular-weight extracellular proteins assessed by gel electrophoresis. One primary and two established glioma lines analysed for DNA content were aneuploid in contrast to diploid fibroblasts. Simultaneous expression of mesenchymal and epithelial markers suggests a dual differentiation potential of glioma cells. Results do not support an endothelial origin for cells cultured from gliomas.     

Müllerian adenosarcoma of the uterus: an ultrastructural study of four cases.

Four cases of uterine müllerian adenosarcoma, a distinctive form of mixed müllerian tumor, were studied by light and electron microscopy. All tumors showed the characteristic histologic pattern of benign neoplastic glands within sarcomatous stroma. Ultrastructurally, both mesenchymal and epithelial cells were seen. The mesenchymal cells showed some features of endometrial stromal cells, including the presence of intracytoplasmic collagen fibers. The epithelial cells formed glands, which resembled benign endometrial glands and were separated from the stroma by a well-defined basal lamina. No transitional cells between the epithelial and mesenchymal cells were seen. The ultrastructural features of these tumors suggest that the sarcomatous portion is of endometrial stromal origin. The glandular portion may arise, along with the stroma, from multipotential stem cells, or the glands may be non-neoplastic entrapped endometrial glands stimulated by the stroma and thus appearing to form an integral part of the tumor.     

Establishment of a clonal human chondrosarcoma cell line with cartilage phenotypes

A clonal cell line with cartilage phenotypes and tumorigenicity during more than 3 years in culture was established from a human chondrosarcoma. In sparse cultures, the clonal line, named HCS-2/8, consisted of slightly elongated polygonal cells, which proliferated with a doubling time of 3.5 days. The cells became polygonal to spherical as they became confluent. After reaching confluence, the cells continued to proliferate slowly and formed nodules, which showed metachromasia when stained with toluidine blue. The nodules were three-dimensional in structure; cells were multilayered in the surface regions, overlying a thick layer of extracellular matrix, which showed metachromasia. Electron microscopically, the cells resembling chondrocytes in vivo were surrounded by an extracellular matrix consisting of thin collagen-like fibrils with numerous fine granules, presumably of proteoglycans. The cells actively synthesized proteoglycans as determined by [35S]sulfate incorporation. The hydrodynamic size of major proteoglycan monomers synthesized by the cells was that of so-called cartilage-specific proteoglycans, as determined by glycerol gradient centrifugation. Immunostaining identified type II collagen but not type I collagen. Fluorography and immunoblotting of collagens separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis also demonstrated the synthesis of type II collagen but not type I collagen. Inoculation of HCS-2/8 cells into athymic mice resulted in the formation of chondrosarcomas that resembled the original tumor. Because of having these characters, HCS-2/8 cells should be useful not only in studies on the differentiated phenotypes of human chondrocytes but also in basic studies on the diagnosis, treatment, and etiology of human chondrosarcomas.     

Collagen formation in extracellular matrix of transplants of human transformed keratinocyte cell lines

BACKGROUND, MATERIALS AND METHODS: The role of epithelial cell growth and neoplastic transformation on collagen formation and deposition in the extracellular matrix (ECM) was analyzed by culturing immortalized human epidermal cell lines and Ras-transformed benign and malignant clones on collagen gels as transplants. The lesions were analyzed for extent of growth and morphology of epithelial and mesenchymal components as well as synthesis and deposition of different collagens. RESULTS: Immortalized cell lines required up to 5 weeks of growth for a well-organized mesenchyme to develop; transplants of Ras-transformed benign clones needed 3 weeks and transplants of highly malignant clones only 2 weeks to form an organized stroma. In transplants of immortalized cells after 2 weeks of growth newly-synthesized collagen type I and type III were deposited in the mesenchyme adjacent to the muscle, forming a mature ECM, while ECM was absent adjacent to growing, differentiated, immortalized cells. In transplants of Ras-transformed benign clones the subepithelial ECM was immature at day 14, but it was forming fibers at the same time in transplants of malignant clones. These were seen as thin irregular fibers in immunohistochemistry, ultimately organized into fibrillar structures in similar locations to active synthesis detected by in situ hybridization. Depositions of crosslinked mature type I collagen occurred later in similar locations. Type III collagen synthesis and deposition was most prominent in transplants of malignant cell clones, with degradation and destruction of the extracellular matrix around invading islets of malignant cells. CONCLUSION: The development of mesenchyme was directly related to duration of growth of transplants and degree of malignancy; mesenchyme organization was inversely related to differentiation of the epithelial cells. The results showed the usefulness of the transplant model in studies on cell and tissue growth and organization.     

Meningeal mesenchymal chondrosarcoma: report of 8 cases with review of the literature.

This paper reviews 8 personally examined cases of primary meningeal mesenchymal chondrosarcoma and 4 similar cases previously reported by others. The clinicopathologic features of these extraosseous intracranial and intraspinal examples are similar to those of other extraskeletal mesenchymal chondrosarcomas. The tumor occurred most often in the second and third decades, showed a moderate tendency to local recurrence (5 of 12 cases) and occasionally metastasized to the lungs (1 case). Both intracranial and intraspinal tumors occurred with equal frequency, but the former, probably due to the later onset of symptoms, had the worse prognosis. Microscopically, they are composed of primitive undifferentiated mesenchymal cells and frequently well-defined islands of hyaline cartilage. There is an apparent correlation between the frequency of mitotic figures and the likelihood of recurrence and metastasis. Electron microscopic study of one example revealed morphologic features similar to those previously described by others and supports the conclusion that the neoplastic cells represent primitive precartilaginous mesenchyme displaying focal cartilaginous differentiation.     

Rb-loss is associated with high malignancy in chondrosarcoma

Loss of function of the human retinoblastoma gene (Rb) is a frequent genetic abnormality in human malignancies and causes a disturbance in the cell cycle and loss of normal proliferation and differentiation. We studied the loss of heterozygosity (LOH) of the Rb gene in 31 formalin-fixed, paraffin-embedded cartilaginous tumors using polymerase chain reaction. The tumors were subdivided into 8 cases of dedifferentiated (DD) chondrosarcoma, 17 cases of conventional chondrosarcoma (nine grade 1, seven grade 2 and one grade 3), 4 enchondromas and 2 chondroblastomas. Both components of DD chondrosarcoma, the low-grade and anaplastic components, were separated by a microdissection approach. The genetic data were correlated with the expression of the Rb protein examined by Rb immunohistochemistry. We found Rb-LOH in one grade 3 chondrosarcoma, and in the anaplastic component in 7 of 8 cases of DD chondrosarcoma (89% of all high-grade chondrosarcomas). All tumors with Rb-LOH were immunohistochemically Rb-negative. The only case of DD chondrosarcoma negative for Rb-LOH in both components of the tumor also showed weak expression of the Rb protein in the anaplastic component. All benign cartilaginous tumors, low-grade chondrosarcomas and low-grade tumor components of DD chondrosarcomas were negative regarding Rb-LOH but positive in Rb immunohistostaining. We concluded that Rb-LOH predominantly occurs in high-grade chondrosarcomas. However, it is not a marker for identifying low-grade tumors with a tendency towards progression or local recurrence.     

Carcinoid of the uterine cervix: additional observations on a new tumor entity.

Twelve carcinoid tumors of the uterine cervix were studied. Based on the microscopic structure, they were divided into well-differentiated and poorly differentiated types. Both tumor varieties affected adult women. The clinical and gross features of these tumors were indistinguishable from those of invasive squamous cell carcinoma. Of the 12 patients, six died, four with poorly differentiated carcinoid and two with the well-differentiated type. Three patients are alive and symptom-free 9 months to 2 years after treatment; the remaining three were lost to follow-up. Microscopically, four well-differentiated carcinoids showed argyrophil cells, and ultrastructurally two had neurosecretory granules. One of the well-differentiated carcinoids resembled islet cell carcinoma and two had areas resembling medullary carcinoma of the thyroid. The poorly differentiated type of carcinoid had a histologic structure and a cell population very similar to that of the oat cell carcinoma of the lung. Of this group, four were argyrophilic, and by electron microscopy four contained pleomorphic secretory granules. It is considered that these tumors arise from the normal argyrophil cell of the cervix and are part of the group of neoplasms of the diffuse endocrine cell system (APUD).     

The clinical approach towards chondrosarcoma

This review provides an overview of the histopathology, classification, diagnostic procedures, and therapy of skeletal chondrosarcoma. Chondrosarcomas that arise de novo are primary chondrosarcomas, whereas chondrosarcomas developing superimposed on pre-existing benign cartilage neoplasms such as enchondromas or osteochondromas are referred to as secondary chondrosarcomas. Conventional chondrosarcomas can be categorized according to their location in bone into central, peripheral, and juxtacortical chondrosarcomas. Histological grading is related to prognosis; however, it is also subject to interobserver variability. Rare subtypes of chondrosarcoma, including dedifferentiated, mesenchymal, and clear cell chondrosarcoma, are discussed as well. Magnetic resonance imaging is necessary to delineate the extent of the intraosseous and soft tissue involvement preoperatively. Computed tomography is especially recommended in the pelvis and other flat bones where it may be difficult to discern the pattern of bone destruction and the presence of matrix mineralization. Wide, en-bloc excision is the preferred surgical treatment in intermediate- and high-grade chondrosarcoma. In low-grade chondrosarcoma confined to the bone, extensive intralesional curettage followed by local adjuvant treatment and filling the cavity with bone graft has promising long-term clinical results and satisfactory local control. Chondrosarcomas are relatively radiotherapy resistant; therefore, doses >60 Gy are needed in attempts to achieve local control after incomplete resection. Irradiation with protons or other charged particles seems beneficial in this curative situation. Chemotherapy is only possibly effective in mesenchymal chondrosarcoma, and is of uncertain value in dedifferentiated chondrosarcoma. Potential new systemic treatment targets are being discussed.     

Immunohistochemical study on clear cell chondrosarcoma]

Clear cell chondrosarcoma, a subtype and separate entity from the conventional chondrosarcoma, is characterized by its special histologic features, site of predilection, slow growth and better prognosis. Three cases are presented with elucidation of clinicopathologic correlation and detection by ABC immunohistochemical method using several antibodies. The observation of positive reaction to S-100 protein, vimentin, anti-alpha-chymotrypsin and Lysozyme by the tumor cells of clear cell chondrosarcoma, similar to chondrosarcoma and chondroblastoma, proves that this tumor has its origin from the cartilaginous tissue. It was found for the first time that the clear cell chondrosarcoma was positive for wheat germ agglutinin and concanavalin A. The authors believe that clear cell chondrosarcoma may result from the anaplastic change of chondroblastoma cells into another subtype of that tumor. The osteoblastlike multinucleated giant cells, retaining the antigens of phagocytes, are not considered to be neoplastic.