Chordomas with malignant spindle cell components. A DNA flow cytometric and immunohistochemical study with histogenetic implications.

The authors studied four chordomas with malignant spindle cell components (SCs) and 12 conventional chordomas (CCs) by DNA flow cytometry using paraffin-embedded tissue. In addition, immunohistochemical stains for a variety of epithelial and mesenchymal markers were performed. The four SCs contained areas histologically identical to conventional chordomas, as well as a high-grade malignant spindle cell component. All four (100%) SCs had an aneuploid-multiploid DNA content. Of interest, the conventional chordoma areas in these tumors had DNA contents different from those containing the high-grade malignant spindle cells. In contrast, only three (27%) of the 11 conventional chordomas with analyzable histograms had an aneuploid-multiploid DNA content. Immunohistochemical studies performed on the four SCs showed the high-grade malignant spindle cells to stain strongly for vimentin and weakly for cytokeratin, S-100 protein, and epithelial membrane antigen (EMA), whereas the areas of conventional chordoma in these same neoplasms stained moderately for vimentin and S-100 protein, and strongly for cytokeratin and EMA. In two cases, the staining for EMA and cytokeratin highlighted a gradual transition between the areas of conventional chordoma and the spindle cell areas. The immunohistochemical staining pattern of the 12 conventional chordomas was similar to that seen in the conventional chordoma components of the four chordomas with malignant spindle cell components. These results suggest that: 1) aneuploidy is more common in SCs than in CCs, and 2) some SCs are multipotential neoplasms in which the neoplastic cells are capable of differentiation along both epithelial and mesenchymal pathways.

DNA in chordomas of the clivus Blumenbachi.

Chordomas of the clivus are frequently denoted as malignant, mainly because of their propensity to recur, their crucial location and the fatal clinical course. Although microscopical examination commonly reveals pleomorphism, particularly of cells and nuclei, the histological assessment of malignancy is not always appropriate. The measurement of DNA could provide important information for a classification of their biological behavior (grading). Our examination of a chondroid chordoma revealed a typical diploid DNA curve within a "benign" 4C range concordant to the favorable course of this variant. Our second examination of a "typical" chordoma showed a wide pleomorphism of cell nuclei and moderate proliferation activity within a "low grade" scale. This pointed to a coming (fatal) recurrence 3.5 years after the first surgery. The third chordoma we examined presented an extraordinary 4C aneuploidy with hypertetraploid subpopulations and an increased number of bi- or poly-nucleated tumor cells with prominent nucleoli and some more mitotic figures. In 5 recurrences the DNA pattern remained principally unchanged.

[Expression of embryonal and differentiational proteins in chordomas and in the notochord].

The expression of the embryonal and of the differentiational proteins in 12 cases of chordoma and in the notochord of a 4-month-old and a 5-month-old human embryo have been examined immunohistologically by the ABC method using polyclonal antibodies to CEA, AFP, or S-100, and the monoclonal antibody to cytokeratin. It was found that S-100 was expressed in all cases of chordoma and in the notochords examined. CEA and cytokeratin also were found expressed in some cases of chordoma but not in the notochords. These proteins were found expressed more strongly in chordomas without a metastasis than in those with a metastasis. In the metastatic lesions, these proteins were expressed more strongly than in the primary lesions. The antibody to AFP reacted with neither the chordomas nor the notochords tested. These results suggest a possible link between the gene-expression of the tumor cells and the microenvironment in which they are harbored.

Positivity to glial fibrillary acidic protein in bone, cartilage, and chordoma.

Twenty vertebral bones, 11 costal, 11 epiglottic, six tracheal, and five bronchial cartilages and seven chordomas were evaluated by the application of peroxidase-antiperoxidase (PAP) indirect immunohistochemical method for localization of glial fibrillary acidic protein (GFAP). Positive immunostaining for GFAP was observed in osteocytes of normal bone (13/20), chondrocytes of normal epiglottis (5/11), costal cartilage (3/11), trachea (2/6), and bronchus (4/5). Four of seven chordomas had neoplastic cells that exhibited cytoplasmic positivity to GFAP. These findings suggested that osteocytes, chondrocytes, and chordoma cells have cytoskeletal intermediate filaments that are antigenically identical to or similar to or associated with GFAP.

[Estrogen receptors in patients with brain tumors].

Estrogen receptor (ER) of brain tumors was assayed in 45 patients. In this series there were 39 cases contained ER, ranged from 0.7 to 188 fmol/mg protein of tumors (mean: 16.1 fmol/mg). The mean level of ER was 10.3 fmol/mg in 20 cases with meningiomas, 8.4 fmol/mg in 11 cases with gliomas, 51.1 fmol/mg in 5 cases with neurilemmomas, 10.5 fmol/mg in 3 cases with medulloblastomas, 16 fmol/mg in 2 organized hematomas due to ruptured AVM, 5.7 fmol/mg in a chordoma, 3.9 fmol/mg in a metastatic carcinoma from thyroid gland, and 0.8 fmol/mg in a cholesteatoma. The presence of ER in the latter several kinds of brain tumors have not been reported in previous literatures. The ER level of the tumors correlated with histological type of tumors, as well as the sex and age of the patients.

Immunohistochemical localization of type II collagen in cartilage-forming tumors.

The presence and distribution of type II collagen was studied in 36 cartilage and cartilage-related tumors, including five osteosarcomas and one chordoma. A monoclonal antibody prepared from chicken type II collagen was used with paraffin sections, employing the ABC (avidin biotinylated horseradish peroxidase complex) peroxidase technique. Fetal cartilage and fracture callus were used as control materials. Type II collagen was present in the matrix of all the cartilage tumors. The reaction was strongest in areas of well-differentiated cartilage and weakest in the poorly differentiated tissue of high-grade chondrosarcomas. Areas of mineralization or ossification, and areas of eosinophilic, fibrous, or degenerated cartilage gave a negative reaction.

Immunohistochemical investigation of chordomas: histogenetic and differential diagnostic aspects.

Chordomas are rare tumors of neuroectodermal origin and often show a very heterogeneous histological picture. In a combined histochemical and immunohistochemical study of 32 chordomas collected in the Bone Tumor Registry of Westphalia we were able to show that the immunoreactivity of the cells in both chordoma and notochordal structures are in close relationship with the extracellular matrix and depends more on the metabolic activity of these cells than on the origin of the cells of the neuroectoderm. All tumor cells show a bimodal immunoreaction with cytokeratin and vimentin, as well as a strong immunoreaction with the oncofetal markers CEA and AFP. The differentiation of chordomas from other malignant tumors, mainly the myxoid variant of chondrosarcoma, may cause major difficulties, especially if only a little biopsy material is available. Here we can see that in tumors with bimodal immunoexpression of vimentin and cytokeratin, as can be found in chordomas, the further use of antibodies offers a reliable differential diagnostic tool. The positive reaction of chordomas with all epithelial tumor markers offers a clear differentiation from chondrosarcomas, which, unlike chordomas, do not express cytokeratin. The identification of a marker profile by employing common antisera is of major value in the differentiation of chordoma from other epithelial or mesenchymal tumors.

A reassessment of "chordoid sarcoma". Ultrastructural and immunohistochemical comparison with chordoma and skeletal myxoid chondrosarcoma.

The relationship of "chordoid sarcoma" (CS) to chordoma and myxoid chondrosarcoma has been debated for several years. In order to reassess this issue, we studied 5 CS, 5 chordomas, and 3 skeletal myxoid chondrosarcomas ultrastructurally and immunohistochemically. By electron microscopy, CS demonstrated smooth cellular outlines, macular intercellular junctions, and cytoplasmic inclusions of matrix-like material. Chordomas displayed a closely similar fine structural appearance, but in addition contained small, membrane-bound, glycogen-containing inclusions. Skeletal myxoid chondrosarcomas resembled CS, except that the former lesions had spiculated cell membranes and lacked intercellular junctions. Immunohistochemically, all CS cases expressed vimentin and lacked cytokeratin (CK). Leu 7 and S100 protein were seen in four cases each of CS, and three of these tumors demonstrated diffuse or focal reactivity for epithelial membrane antigen (EMA). Similar phenotypic features were seen in chordomas, except that all of them stained diffusely for CK, as well as EMA. Skeletal myxoid chondrosarcomas expressed vimentin, S100, and Leu 7 uniformly, but were devoid of epithelial markers. In aggregate, these data support the classification of "chordoid sarcoma" as a form of chondrosarcoma, but reveal that it may exhibit an "epithelial" antigen in some cases.

S-100 protein and neuron specific enolase (NSE) expression by chordomas in relation to the composition of their stromal mucosubstances.

The immunoreactivity of S-100 protein and neuron specific enolase (NSE.) was correlated with the composition of stromal glycosaminoglycans in chordomas and human notochords, in a combined histochemical and immunohistochemical study. We found that S-100 protein is negative in notochordal and chordoma cells in the absence of stromal mucosubstances or in the presence of small quantities of hyaluronic acid. The positivity of S-100 immunoreaction was found to be related to the presence of stromal glycosaminoglycans of the chondroitine sulfate A and C type. NSE. was found positive in cells presenting features of high metabolic activity. Consequently S-100 protein and NSE. immunoreactivity cannot have any cytogenetic implications, but they could be considered as markers indicating specific cell-stromal functional interactions.

[Chordomas]. / Chordomes.

Chordomas are slowly growing malignant tumors arising from notochordal rests. They are occurring in adults (50 to 60 year old) and are mainly (85%) located in sacrococcygeal or spheno-occipital regions; other main localization is cervical spine. Chordomas are usually discovered in patients with pain or symptoms due to compression of surrounding viscera. Radiologically it is characterized by association of osteolysis and soft tissues opacity. On macroscopic examination tumoral tissue has mucoid appearance; under microscope it is made up with lobules of epithelial-appearing cells surrounded by acid mucosubstances. Tumorous cells contain glycogen and neutral mucosubstances. They are surrounded by argyrophilic rim due to pericellular condensation of intercellular matrix, well viewed on electron microscope examination. When their cytoplasm is filled with vacuoles, cells take up typical physaliphorous appearance. Chordomas cells express epithelial differentiation antigens (low molecular weight cytokeratins, EMA, CAM 52, HFM 62, even CEA), Vimentin and S-100 Protein: this triple positivity allow differentiation between chordomas and numerous others tumors. Correct treatment of chordoma is achieved with an initially complete excision. Local recurrences are frequent and sometimes inoperable: in this cases radiotherapy alone may be performed (70 grays). Sarcomas (fibroblastic or Malignant fibrous histiocytoma) may occur after radiotherapy or without it. Hematogenous metastasis occur in 10% to 15% of patients. Survival rate at five years is included between 50% and 75%. Chondroid chordoma is a special entity occurring in younger patients (35 year old) and located in spheno-occipital region. In addition to chordomas it contain chondroid (benign or malignant) islands. Mean survival rate (16 years) is far better than for chordoma or chondrosarcoma.

Demonstration of cytokeratins and an epithelial membrane antigen in chondroid chordoma.

Chondroid chordomas are shown to possess cytokeratins and to stain with HMFG-2 as do ordinary chordomas. These findings support the concepts that these neoplasms are a variant of chordoma and that they are unrelated to myxoid chondrosarcoma.

Chordomas--ultrastructure and immunohistochemistry: a report based on the examination of six cases.

Six chordomas (three classic and three chondroid) were examined ultrastructurally and with a panel of monoclonal antibodies. The three classic tumours showed the presence of desmosomes and intermediate filaments on electron microscopy, findings which gave a direct positive correlation when the tumours were stained with monoclonal antibodies against low molecular weight cytokeratin proteins. These results suggest that chordomas are essentially epithelial neoplasms and underline the fact that monoclonal antibodies to cytokeratins cannot be used in the differential diagnosis of classic chordoma vs carcinoma. Furthermore, the epithelial characteristics are lost as the tumour undergoes chondroid differentiation.

"Dedifferentiated" chordoma. A clinicopathologic and immunohistochemical study of three cases.

Three cases of "dedifferentiated" chordoma arising in the sacrococcygeal region are presented. In all three cases, the "dedifferentiated" component arose de novo in conjunction with conventional chordoma. Two of these patients, whose tumors had a prominent malignant fibrous histiocytoma (MFH) component, died within 6 months of diagnosis. Both patients had lung metastases, one of which was histologically documented to be MFH. The third patient, whose initial tumor contained osteosarcoma, died 76 months after diagnosis and multiple recurrences. Most notable in this case was the absence of the "dedifferentiated" component (in this instance, osteosarcoma) in all of the local recurrences as well as the lung metastases. These were composed exclusively of conventional chordoma. None of the patients had a previous history of radiation therapy. The immunohistochemical staining pattern of conventional chordoma was similar to that of previous reports, where the epithelial-like cells stained for cytokeratin and epithelial membrane antigen. In addition, they stained for alpha-1-anti-chymotrypsin and vimentin. These latter two markers were also identified in the "dedifferentiated" component. As with "dedifferentiated" chondrosarcomas and liposarcomas, "dedifferentiation" in a chordoma usually portends an accelerated clinical course.

Chordoma with a massive spindle-cell sarcomatous transformation. A light- and electron-microscopic and immunohistological study.

A 26-year-old woman was operated on for a bulky tumor in the sacral region; she died of massive local tumor recurrence and pulmonary metastases 3 months later. Most of the original tumor showed a highly cellular spindle-cell sarcoma compatible with a fibrosarcoma of a high grade of malignancy. In a few small areas of the tumor, a chordoma-like pattern surrounded by growth of spindle-cell sarcoma was found. The spindle-cell component exhibited vimentin positivity in all tumor cells, but many cells were also cytokeratin-positive. The chordoma-like areas showed cytokeratin in all tumor cells. The chordoma-like areas, but not the spindle-cell areas also were positive for epithelial membrane antigen and S-100 protein. This case indicates that the sarcomatous change associated with chordoma may contain keratins as a sign of epithelial differentiation, and may thus represent sarcomatous transformation of chordoma cells, rather than a coincidental soft-tissue sarcoma or collision tumor.

Does chondroid chordoma exist?

The existence of chondroid chordoma (CC), initially described in 1973, has remained controversial. Since the antigenic profiles of both chordoma (CD) and cartilaginous (chondroid) lesions have been well characterized, we decided to study chondroid chordoma immunohistochemically. Our hypothesis was that chondroid chordoma should display a hybrid or mixed pattern of staining: chordomatous areas with an epithelial phenotype and cartilaginous areas with a mesenchymal (non-epithelial) phenotype. An analysis of CC (seven cases) was performed and compared with results obtained on notochord, cartilage, classic CD (18 cases), peripheral chondromas (two cases), and peripheral chondrosarcomas (CS, eight cases). Four epithelial markers were employed: MKER and AE-1 (both monoclonal antibodies to cytokeratin); PKER (a polyclonal antibody to cytokeratin); and, EMA (epithelial membrane antigen). In addition, selected cases were tested for the presence of neurofilament (NF) and glial fibrillary acidic protein (GFAP). All 18 CD's exhibited the expected epithelial immunophenotype - MKER+, AE-1+, PKER+, and EMA+ - a reaction pattern nearly identical to that found in fetal notochord. This reinforced the importance of the growth pattern in assessing the presence of chordomatous elements. All chondromas and CS's failed to express any of the epithelial markers studied and contained only S-100 immunoreactivity, like cartilage. Chondroid chordoma resembled cartilaginous tumors immunohistochemically; no mixed pattern with even focal epithelial marker reactivity was identified. All CC tested were also NF and GFAP negative. We conclude that CC either does not exist or is extremely rare and that these tumors are cartilaginous in nature.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunohistological study in chordomas.

An immunohistological study of 15 chordomas, six chondrosarcomas, four liposarcomas and seven carcinomas on paraffin embedded samples using anti-cytokeratin, anti-epithelial membrane antigen (EMA), anti-S100 protein, anti-vimentin and anti-neurofilaments showed that chordomas has a characteristic immuno-staining, i.e. positive for cytokeratin, EMA, S100 protein and vimentin; and negative for neurofilaments. This immuno-staining allows a clear distinction of chordomas from other tumours.

[Immunohistochemical studies of chordomas and choroid tumors]. / Immunhistochemische Untersuchungen an Chordomen und chondroiden Tumoren.

Chordomas are rare slow-growing but locally invasive tumors. They are thought to develop from residues of the notochord. Three chordomas and ten chondroid tumors were investigated by an indirect immunoperoxidase method for expression of the epithelial markers: MAM-6, keratin, tissue polypeptide antigen (TPA) and for carcinoembryonic antigen (CEA). In all the chordomas investigated the antigens MAM-6, keratin and TPA were detected using monoclonal antibodies and conventional antisera, respectively. These data provide further evidence of the epithelial nature and the ectodermal origin of chordomas. Moreover, the findings suggest that immunohistochemical methods may be useful for the differential diagnosis between chordomas and morphologically similar chondroid tumors.

Tissue polypeptide antigen staining of the chordoma and notochordal remnants.

Tissue polypeptide antigen (TPA) has been increasingly used as an immunological marker for tumors derived from the lining epithelia of body cavities, including those of the gastrointestinal tract and genitourinary and bronchopulmonary systems. Here, we present evidence that this antigen is consistently and strongly expressed by a nonepithelial lesion - the chordoma. Irrespective of their sites, all seven chordomas, including one chondroid lesion, were heavily stained. In contrast, five chondrosarcomas were unstained or showed only focal slight positivity. TPA staining was also found to be strongly expressed by notochordal rests within the intervertebral disks of one newborn and five fetuses (15th to 32nd week of gestation), adding further evidence that these rests are the histogenetic origin of the chordoma.

Demonstration of cytokeratins and an epithelial membrane antigen in chordomas and human fetal notochord.

The application of immunohistochemical staining with anti-epithelial monoclonal antibodies to the differential diagnosis of chordomas is described. Cytokeratins and an epithelial membrane-specific oligosaccharide sequence are found in chordomas but not in chondrosarcomas or normal cartilage. The same cytokeratins and oligosaccharide sequence are demonstrated in human fetal notochord. Immunohistochemical staining with antiepithelial antibodies is therefore of value in distinguishing chordomas from cartilaginous tumours. The staining of notochord with the same monoclonal antibodies adds weight to the proposition that chordomas arise from embryonic rests of notochordal cells.