Patterns of brachyury expression in chordomas.

INTRODUCTION: Chordomas are rare malignant midline tumors, presumed to arise from notochordal remnants. This was further suggested by the discovery of the brachyury in chordomas pathogenesis. Its immunohistochemical expression has become the principal adjunct in the diagnosis of chordomas. However, studies about brachyury expression in chordomas are not fully comparable, mainly because they use different primary antibodies. Thus, the aim of this study is to investigate the expression of brachyury expression in a series of chordomas in conjunction to clinicopathological characteristics and to review the relevant literature providing all the details needed in the immunohistochemical study of brachyury. MATERIALS AND METHODS: This is a retrospective study of 62 chordomas, diagnosed over a 22-year period. No dedifferentiated or poorly differentiated cases were included. A monoclonal primary antibody (clone A-4) was used and brachyury expression was evaluated by the H-score. Clinicopathological parameters studied were age, sex, tumor localization, decalcification status and tissue age. Fetal notochords were used for comparison. RESULTS: Mean H-score of nuclear brachyury expression was 129.8. The tissue age significantly influenced brachyury expression, the older samples expressing less brachyury. Decalcification demonstrated a trend to weaken brachyury expression. Clinical characteristics were not correlated with the patterns of brachyury expression. Notochords were negative. Literature review reveals several polyclonal antibodies used and a positivity of 75%-100% in chordomas with even more variable results in notochords. CONCLUSION: In chordomas, as in other tumor types, an uniformization of studies about brachyury expression is needed, by considering the clone used, and the decalcification and the age of the sample, given the growing importance of brachyury in diagnosis and therapeutic steps.

MRI Signal Intensity and Electron Ultrastructure Classification Predict the Long-Term Outcome of Skull Base Chordomas.

BACKGROUND AND PURPOSE: MR imaging is a useful and widely used evaluation for chordomas. Prior studies have classified chordomas into cell-dense type and matrix-rich type according to the ultrastructural features. However, the relationship between the MR imaging signal intensity and ultrastructural classification is unknown. We hypothesized that MR imaging signal intensity may predict both tumor ultrastructural classification and prognosis. MATERIALS AND METHODS: Seventy-nine patients with skull base chordomas who underwent 95 operations were included in this retrospective single-center series. Preoperative tumor-to-pons MR imaging signal intensity ratios were calculated and designated as ratio on T1 FLAIR sequence (RT1), ratio on T2 sequence (RT2), and ratio on enhanced T1 FLAIR sequence (REN), respectively. We assessed the relationships among signal intensity ratios, ultrastructural classification, and survival. RESULTS: Compared with the matrix-rich type group, the cell-dense type chordomas showed lower RT2 (cell-dense type: 1.90 ± 0.38; matrix-rich type: 2.61 ± 0.60 P < .001). The model of predicting cell-dense type based on RT2 had an area under the curve of 0.83 (95% CI, 0.75-0.92). In patients without radiation therapy, both progression-free survival (P = .003) and overall survival (P = .002) were longer in the matrix-rich type group than in the cell-dense type group. REN was a risk factor for progression-free survival (hazard ratio = 10.24; 95% CI, 1.73-60.79); RT2 was a protective factor for overall survival (hazard ratio = 0.33; 95% CI, 0.12-0.87); and REN was a risk factor for overall survival (hazard ratio = 4.76; 95% CI, 1.51-15.01). CONCLUSIONS: The difference in MR imaging signal intensity in chordomas can be explained by electron microscopic features. Both signal intensity ratios and electron microscopic features may be prognostic factors.

EM proves invaluable in the confirmation of chordoma in the sacral mass of a middle-aged man.

A case of a 47-year-old male with a sacral spine mass was investigated by histology, immunohistochemistry (IHC), and electron microscopy (EM). The light microscopy of the first core biopsy revealed scant cellularity with spindle and round cells with eosinophilic cytoplasm within a fibromyxoid background. Immunostaining with pancytokeratin, cytokeratin 19, and S100 was nonspecific. Another biopsy was attempted to obtain a more definitive diagnosis. Light microscopy of the second core had scant cellular material. However, the tissue was specifically requested for ultrastructural evaluation and revealed features diagnostic of chordoma. After definitive diagnosis, radical resection of the mass was performed. This case illustrates how EM was instrumental in the definitive diagnosis before radical resection in a case that was not clear by hematoxylin and eosin (H&E) and IHC alone.

Prognostic Value of a Category Based on Electron Microscopic Features of Clival Chordomas.

OBJECTIVE: Skull base chordomas are clinically malignant because of the difficulty of total removal and the high recurrence rate. Because the disease-free survival after surgery is currently unpredictable, there is a need for new parameters, obtained from histologic analyses of the resection specimen, that allows a risk stratification of patients with chordoma. METHODS: In recent years, electron microscopic diagnoses were introduced into the clinical practice for the diagnosis of chordoma in our department. Clinical outcomes and electron microscopic features were retrospectively reviewed in the study. The electron micrograph shows that clival chordoma can be divided into cell-dense type (CDT) and matrix-rich type (MRT). Of all the patients with chordoma, complete data from 27 patients were obtained. There were 12 patients in the CDT group and 15 patients in the MRT group. The paraffin-embedded tissue samples were stained with Ki-67 antibody. The prognostic values of electron microscopic classification were compared between the 2 groups. RESULTS: There were no statistical differences in the gender (P = 0.704) and age distribution (P = 0.243) between the 2 groups. There was also no statistical difference concerning the constitution of primitive tumors and recurrent tumors between the 2 groups (P = 0.706). The CDT group had a higher mortality rate than the MRT group (P = 0.037). The tumors in the CDT group were prone to recurrence and the need for reoperation within 1 year after surgery, which is statistically different from that in the MRT group (P < 0.001). Chordoma tumors of 23 patients (85.2%) stained positive for Ki-67. CDT chordomas had a higher Ki-67 proliferation index than the MRT chordomas (P = 0.013). CONCLUSIONS: The present study demonstrates the utility of the ultrastructural features in the prognostic outcome of patients with chordoma. According to the ultrastructures of chordomas, they can be divided into CDT and MRT. CDT chordoma cells have a more aggressive proliferative ability. Patients with CDT have a poor prognostic factor in clival chordoma, which has a higher risk of recurrence and a shorter survival.

Extended ultrastructural characterization of chordoma cells: the link to new therapeutic options.

Chordomas are rare bone tumors, developed from the notochord and largely resistant to chemotherapy. A special feature of this tumor is the heterogeneity of its cells. By combining high pressure freezing (HPF) with electron tomography we were able to illustrate the connections within the cells, the cell-cell interface, and the mitochondria-associated endoplasmic reticulum membrane complex that appears to play a special role among the characteristics of chordoma. These lipid raft-like regions are responsible for lipid syntheses and for calcium signaling. Compared to other tumor cells, chordoma cells show a close connection of rough endoplasmic reticulum and mitochondria, which may influence the sphingolipid metabolism and calcium release. We quantified levels of ceramide and glycosylceramide species by the methyl tert-butyl ether extraction method and we assessed the intracellular calcium concentration with the ratiometric fluorescent dye Fura-2AM. Measurements of the changes in the intracellular calcium concentration revealed an increase in calcium due to the application of acetylcholine. With regard to lipid synthesis, glucosylceramide levels in the chordoma cell line were significantly higher than those in normal healthy cells. The accumulation of glycosylceramide in drug resistant cancer cells has been confirmed in many types of cancer and may also account for drug resistance in chordoma. This study aimed to provide a deep morphological description of chordoma cells, it demonstrated that HPF analysis is useful in elucidating detailed structural information. Furthermore we demonstrate how an accumulation of glycosylceramide in chordoma provides links to drug resistance and opens up the field for new research options.

Resolving tumor heterogeneity: genes involved in chordoma cell development identified by low-template analysis of morphologically distinct cells.

The classical sacrococcygeal chordoma tumor presents with a typical morphology of lobulated myxoid tumor tissue with cords, strands and nests of tumor cells. The population of cells consists of small non-vacuolated cells, intermediate cells with a wide range of vacuolization and large heavily vacuolated (physaliferous) cells. To date analysis was only performed on bulk tumor mass because of its rare incidence, lack of suited model systems and technical limitations thereby neglecting its heterogeneous composition. We intended to clarify whether the observed cell types are derived from genetically distinct clones or represent different phenotypes. Furthermore, we aimed at elucidating the differences between small non-vacuolated and large physaliferous cells on the genomic and transcriptomic level. Phenotype-specific analyses of small non-vacuolated and large physaliferous cells in two independent chordoma cell lines yielded four candidate genes involved in chordoma cell development. UCHL3, coding for an ubiquitin hydrolase, was found to be over-expressed in the large physaliferous cell phenotype of MUG-Chor1 (18.7-fold) and U-CH1 (3.7-fold) cells. The mannosyltransferase ALG11 (695-fold) and the phosphatase subunit PPP2CB (18.6-fold) were found to be up-regulated in large physaliferous MUG-Chor1 cells showing a similar trend in U-CH1 cells. TMEM144, an orphan 10-transmembrane family receptor, yielded contradictory data as cDNA microarray analysis showed up- but RT-qPCR data down-regulation in large physaliferous MUG-Chor1 cells. Isolation of few but morphologically identical cells allowed us to overcome the limitations of bulk analysis in chordoma research. We identified the different chordoma cell phenotypes to be part of a developmental process and discovered new genes linked to chordoma cell development representing potential targets for further research in chordoma tumor biology.

Paracordoma recidivante en la mano de un niño. Comunicación de un caso y revisión de la literatura / Recurring parachordoma in the hand of a child. A case report and review of the literature

El paracordoma es una neoplasia infrecuente de partes blandas que forma parte del espectro tumor mixto/mioepitelioma. Descrito en la década de 1950, se han comunicado 64 casos, 10 de los cuales corresponden a niños. El rango etario es amplio, con una media en la cuarta década. El paracordoma es morfológicamente similar al cordoma, pero su localización es extraaxial, preferentemente en la porción proximal de las extremidades, y posee un patrón inmunohistoquímico característico. Esta neoplasia es de crecimiento lento y localmente agresivo, pero se han informado casos con metástasis. Se presenta un niño de 8 años con un paracordoma de un año de evolución en la mano izquierda, que recidivó a los 6 meses de la cirugía inicial(AU)

Parachordoma is an unusual soft tissue tumour, falling within the mixed tumor/myoepithelioma spectrum. Only 64 cases have been reported since it was first described in 1950; of these 10 occurred in children. The overall age range is broad but the majority of patients are between 40 and 50 years old. Morphologically it is similar to chordoma but with an extraaxial location, occurring most frequently in the proximal limbs. Furthermore, it shows a different pattern with immunostaining. It is a slow growing tumour with local invasion, although metastases have been reported. We present a case of parachordoma in an 8 year old boy who presented with a slow growing mass in his left hand which recurred 6 months post-operatively(AU)

Establishment and characterization of a novel chordoma cell line: CH22.

Chordoma is a rare primary malignant bone tumor and there exist only a few established human chordoma cell lines. The scarcity of robust chordoma cell lines has limited the ability to study this tumor. In this report, we describe the establishment of a novel chordoma cell line and characterize its in vitro and in vivo behaviors. The tumor tissue was isolated from a patient with recurrent chordoma of the sacrum. After 6 months in culture, the chordoma cell line, referred here as CH22, was established. Microscopic analysis of two-dimensional culture confirmed that the CH22 cells exhibited a typical vacuolated cytoplasm similar to the well-established chordoma cell line U-CH1. Electron microscopy showed cohesive cells with numerous surface filopodia, pockets of glycogen and aggregates of intermediate tonofilaments in cytoplasm. Three-dimensional culture revealed that the CH22 cells could grow and form clusters by day 8. The MTT assays demonstrated that, compared with sensitive osteosarcoma cell lines, CH22 cells were relatively resistant to conventional chemotherapeutic drugs. Western blotting and immunofluorescence analysis confirmed that the CH22 cells expressed brachyury, vimentin, and cytokeratin. Finally, histological analysis of CH22 xenograft tumor tissues demonstrated the appearance of physaliphorous cells and positive staining of brachyury, cytokeratin, and S100. By CT and MRI, imaging xenografts showed the typical appearances seen in human chordomas. These findings suggest that the established novel human chordoma cell line CH22 and its tumorigenecity in SCID nude mice may serve as an important model for studying chordoma cell biology and the development of new therapeutic modalities.

Chondroid chordoma of the skull base: immunohistochemical and ultrastructural study of two cases with special reference to microtubules within rough-surfaced endoplasmic reticulum.

Two cases of skull base chordoma (case 1, a 57-year-old woman; case 2, a 69-year-old woman) were investigated immunohistochemically and ultrastructurally. The tumors showed histopathological features typical of chondroid chordoma and contained both classical chordomatous and hyaline cartilaginous components. Tumor cells were immunoreactive for cytokeratin, vimentin, and S-100 protein, but negative for microtubule-associated protein 2 and class III beta-tubulin (tub-B3). Tumor cells of case 2 were immunoreactive for tau-protein and class II beta-tubulin (tub-B2), whereas those of case 1 were negative. Ultrastructurally, tumor cells in both cases showed the presence of abundant glycogen granules, well-developed intracellular organelles, and desmosome-like junctions. In case 2, several microtubules were closely packed and ran parallel or in random directions within the dilated cisterns of rough-surfaced endoplasmic reticulum (rough ER). "Microtubules within rough ER" has been described in several neoplasms, including classical and chondroid chordomas. Although previous reports documented the tub-B3 immunoreactivity in chordomas, our results suggested that, in our case 2, the predominant isoform of beta-tubulin in microtubules within rough ER was not tub-B3 but tub-B2.

[Chordomas]. / Les chordomes.

Chordoma is a rare bone tumor, believed to derive from notochordal rests, which generally arises at the two extremities of axial skeleton. We present a literature review on chordomas. Diagnosis has been greatly improved by MRI and immunohistochemistry. Conversely, complementary immunohistochemistry, cytometry and cytogenetic techniques have failed to improve prognosis evaluation. Radical surgery with free surgical margins is the most accurate curative treatment. Progress in radiotherapy should offer new therapeutic perspectives in the future. The recognition of new entities such as giant notochordal rest or hamartoma, and notochordal cells benign tumor, can lead to confusion since there is no consensus regarding their nature and whether or not they correspond to chordoma precursors. Prudence should be the rule in order to avoid overtreatment.

Parachordoma is not distinguishable from axial chordoma using immunohistochemistry.

Parachordoma is a rare soft tissue tumor that morphologically resembles chordoma of the axial skeleton but occurs in a peripheral site. A recent study reported immunohistochemical differences between chordoma and parachordoma. While both tumors were positive for cytokeratin (CK) 8/18 (as recognized by the antibody Cam5.2), S100 and epithelial membrane antigen (EMA), only the chordoma was positive for CK7, CK20, CK 1/5/10/14 (as recognized by the antibody 34betaE12) and carcinoembryonic antigen (CEA). It has since been suggested that tumors indistinguishable from chordoma that involve the periphery should be termed chordoma periphericum and that these tumors are distinct from parachordoma. In the current study, the clinical, radiological, pathological, immunohistochemical and ultrastructural features of a chordoma-like tumor involving the deep soft tissues of the lower leg of a 69-year-old woman are presented. Microscopically, the tumor had a pseudolobulated growth pattern and consisted of sheets, nests and cords of epithelioid cells, some with a physaliferous appearance, separated by abundant myxoid stroma. The tumor cells were positive for CK 8/18, EMA and S100, showed focal staining for CK7, and were negative for CK20, CK 1/5/10/14 and CEA. On the basis of these results a diagnosis of parachordoma was favored. For comparison, an immunohistochemical analysis of five axial chordomas was also performed. The chordomas showed positivity for CK 8/18 (5 of 5 cases), EMA (5 of 5 cases), S100 (5 of 5 cases), CK 1/5/10/14 (1 of 5 cases) and CK7 (1 of 5 cases). Stains for CK20 and CEA were negative in all five chordomas. The results of the present study suggest that the expression of antigens for CK 1/5/10/14, CK7, CK20 and CEA in chordoma might not be as common as what has been previously reported. The results also suggest that parachordoma might not be easily distinguished immunohistochemically from axial chordoma (and therefore also from so-called chordoma periphericum).

[Morphological characteristics of chordoma of the temporal bone: light amd electron microscopy]. / Morfologicheskie osobennosti khordomy visochnoi kosti: svetovaia i élektronnaia mikroskopiia.

For the first time chordoma of the temporal bone in a female aged 24 years is described. The tumor was studied histologically and ultrastructurally.

Chordoma: a cytologic study with histologic and radiologic correlation.

BACKGROUND: Chordoma is a rare malignant tumor of fetal notochord origin that occurs along the spinal axis. The fine-needle aspiration biopsy (FNAB) findings are described, correlated with histology and radiology, and compared with previously reported descriptions of chordoma. METHODS: Fine-needle aspiration biopsies of 12 cases of chordoma with histologic confirmation were reviewed. Imaging studies were reviewed in seven cases. Cytologic material included smears, ThinPrep, and cell blocks. Immunostains were performed on selected cytologic and histologic specimens. Multiple cytologic parameters were studied. RESULTS: Eleven specimens were from the spinal axis, and one was from a chest wall metastasis. Ten cases were diagnosed as chordoma on cytologic material, one was positive for malignancy with a differential diagnosis of chordoma and well differentiated chondrosarcoma, and one was positive for malignancy, not further classified. Most smears were moderately to highly cellular and demonstrated typical physaliphorous cells and a myxoid background. Two of the 10 cases diagnosed as chordoma showed pleomorphic physaliphorous cells, nuclear inclusions, and binucleation. Nuclear inclusions were observed in three other cases diagnosed as chordoma. Histologic follow-up of one case with pleomorphic physaliphorous cells showed conventional chordoma with focal areas of increased cellularity and pleomorphism. Pleomorphic sarcomatous cells were the predominant cell type in one case that showed dedifferentiated chordoma histologically. Mitotic figures were rarely observed in cytologic material. CONCLUSIONS: Cytomorphologic features of chordoma allow accurate diagnosis by FNAB. Features associated with dedifferentiation include increased pleomorphism of physaliphorous cells and may include nuclear inclusions, bi- or multinucleation, and rarely, mitotic figures. Cancer (Cancer Cytopathol)

Chondroid chordoma: fine-needle aspiration cytology with histopathological, immunohistochemical, and ultrastructural study of two cases.

Chondroid chordoma is a controversial and confusing entity that was originally described by Heffelfinger et al. (Cancer 1973; 32:410-420) as a biphasic malignant neoplasm possessing elements of both chordoma and cartilaginous tissue. Fine-needle aspiration (FNA) cytology of chondroid chordoma has not been described. The aim of our investigation was to characterize the chondroid area of chondroid chordoma and to compare the FNA features with those of well-differentiated chondrosarcoma. Clival and cervical spine chondroid chordomas were studied with light microscopy, immunohistochemistry, and electron microscopy. Chondroid chordomas demonstrated an epithelial nature by immunohistochemistry and ultrastructural studies. The FNA smears showed low cellularity, with loosely arranged or dispersed round cells in a myxoid background. Although the smears were similar to those of well-differentiated chondrosarcomas, they showed a positive reaction for epithelial markers. These findings reveal that chondroid chordoma is a variant of chordoma which possesses a hyaline matrix. Immunohistochemical demonstration of epithelial markers is useful to distinguish it from chondrosarcoma. Diagn. Cytopathol. 1999; 21:335-339.

Clear cell meningioma of the lumbo-sacral spine with chordoid features.

Clear cell meningioma (CCM) is a peculiar variant that differs from conventional meningioma in affecting younger patients, arising more often in spinal or cerebellopontine locations, and showing a higher recurrence rate. Classical meningothelial areas are scarce in these tumors and the differential diagnosis with other neoplasms, particularly metastatic carcinoma, is often difficult. We report a case of clear cell meningioma from the lumbosacral spine in which location, radiologic presentation, light microscopic appearance in initial sampling, and some of the ultrastructural findings were reminiscent of chordoma. The tumor cells were diffusely positive for vimentin and very focally positive for epithelial membrane antigen. Ultrastructural demonstration of interdigitating cell processes joined by numerous desmosomes confirmed the diagnosis of CCM.

Cytogenetic analysis of a parachordoma.

We report the cytogenetic and histopathological findings in a 7-year-old female child with an intranasal tumor that is most consistent with a parachordoma. Karyotypic analysis of the tumor revealed clonal numerical and structural chromosome abnormalities. Seven cells displayed recurrent changes: der(2)t(2;4), del(3q), and the loss of chromosomes 9, 10, 20, and 22. Four cells showed a loss of chromosome 17. To the best of our knowledge, these are the first clonal chromosome abnormalities described in parachordoma.

[Pharyngeal chordoma]. / Cordoma faríngeo.

Chordoma is a neoplasm arising from embryonal notochord remnants. It is infrequent and rarely located at the cervical level. The diagnosis is histological and immunohistochemical tests are required to differentiate it from other neoplasms. We report a case of pharyngeal chordoma treated with a transmandibular approach. The diagnosis, treatment, and prognosis of these tumors are reviewed.

Chordomas of the mediastinum: clinicopathologic, immunohistochemical, and ultrastructural study of six cases presenting as posterior mediastinal masses.

Six cases of chordomas presenting as primary posterior mediastinal tumors are described. Three patients were female, and three were male between the ages of 8 and 65 years (mean, 40.6 years). In all cases, the tumors presented radiographically as relatively well-circumscribed, encapsulated soft tissue masses that did not seem to be related to the thoracic or dorsal spine. Only in one case, focal infiltration of bone at the level of T6-T7 was observed at the time of surgery. Histologically, the lesions showed a spectrum of features that ranged from sheets and cords of large cells with abundant vacuolated cytoplasm to small, stellate cells embedded within an abundant mucoid matrix. In one case, the cell population showed more pronounced nuclear atypia with loss of cytoplasmic vacuolization, frequent mitotic figures, necrosis, and solid areas characterized by a perivascular distribution of atypical spindle cells set against a myxoid stroma. Another case showed features of chondroid chordoma, with an immature chondroid-appearing matrix surrounding the atypical tumor cells. Immunohistochemical studies in all cases showed positive staining of the tumor cells with CAM 5.2 and broad-spectrum keratin, epithelial membrane antigen (EMA) and vimentin, and, to a lesser extent, with S-100 protein. Stains for muscle actin, carcinoembryonic antigen (CEA), and desmin were negative. Ultrastructural examination in two cases showed a spectrum of features that varied from large cells with abundant cytoplasm containing scattered ribosomes, glycogen granules, Golgi apparatti, abundant intermediate filaments, and small lumen formation with immature microvilli to smaller cells with elongated cytoplasmic processes, fewer intermediate filaments, rare desmosome type intercellular junctions, and complexes of mitochondria/rough endoplasmic reticulum. On clinical follow-up, two patients died with metastases to the lungs, chest wall, and liver from 1 to 3 years after diagnosis, and two patients are alive and well without evidence of disease after 3 and 16 years. Chordoma should be entertained in the differential diagnosis of posterior mediastinal tumors. Application of immunohistochemical stains or electron microscopy will be of aid in separating them from other conditions that may histologically closely resemble these lesions.

Intracisternal microtubular aggregates in classic (non chondroid) chordoma.

A case of unequivocal and classic (non chondroid) chordoma with cells including microtubular aggregates is reported. Parallel arrays of straight or slightly curved and evenly spaced 22-26 nm microtubules, showing a fine periodicity and without internal structure, were confined within dilated cisternae. These cisternae were characterized by a single layered limiting membrane, without associated ribosomes. This is the second reported occurrence of such microtubules in a spheno-occipital classic chordoma. It emphasizes the nonspecificity of this finding namely in reference to extraskeletal myxoid chondrosarcoma or chondroid chordoma. Furthermore, intracytoplasmic true lumina were found to partly account for the cellular vacuolar character on light microscopy, an observation generally underscored in chordoma cells.