Cell morphology: Physaliferous: T expression: Positive; 19.5x that of U-CH2: T localization: . microscopy, chordoma resembles notochord.16 Histologi-cally, chordoma is commonly characterized by vacuolated cells known as physaliferous cells arranged in a lobular arrangement.17 In ferrets, chordoma has a unique appearance with a regular zonal pattern of lobules of physaliferous cells A chordoma is an uncommon tumor that originates from the remnants of the notochord and most commonly involves the cranial and caudal regions of the axial skeleton. Chordomas are the only malignant tumors arising from the notochord elements and occur in the midline of the body. physaliphorous cell: cells containing a bubbly or vacuolated cytoplasm, for example, as characteristically seen in chordoma. Chordomas are known as rare primary malign tumours that have formed from primitive notochord remains. The histological appearance of classical chordoma is of a lobulated tumor composed of groups of cells separated by fibrous septa. The cells have small round nuclei and abundant vacuolated cytoplasm, sometimes described as physaliferous (having bubbles or vacuoles ). The population of cells consists of small non-vacuolated cells, intermediate cells with a wide range of vacuolization and large heavily vacuolated (physaliferous) cells. Epidemiology Pathology Ecchordosis physaliphora arise from remaining notochord cells along the axis of the spine after embryogenesis. The classical sacrococcygeal chordoma tumor presents with a typical morphology of lobulated myxoid tumor tissue with cords, strands and nests of tumor cells. Pathogenesis and Molecular Biology of Chordoma 23 . Cell morphology: Physaliferous: T expression: Positive; 10x that of U-CH2 with overexpression but no amplification: T localization: Nuclear: CD24 expression: . Establishment and characterization of a novel chordoma cell line: CH22. Chordoma has been described in laboratory animals such as dogs, rats, minks, and ferrets. Choy E et al. Molecular Drivers in Chordoma . The other diagnosis, of . Liu X, Nielsen GP, Rosenberg AE, Waterman PR, Yang W, Choy E, Sassi S, Yang S, Harmon DC, Yang C, Schwab JH, Kobayashi E, Mankin HJ, Xavier R, Weissleder R, Duan Z, Hornicek FJ . Chordomas are typically slow-growing masses. Chordomas, Cytological Findings, Fig. Treatment is usually wide margin surgical resection with or without radiation. DEDIFFERENTIATED VARIETY 10. 1 Chordoma: tumor cells with round, monomorphic nuclei and rich cytoplasm with large vacuoles (physaliferous cells). (2010) Characterization and analysis of human chordoma cell lines. The remaining cellular tumors were composed of poorly differentiated epithelioid cells set in a fibrous stroma and lacked physaliferous cells (poorly differentiated chordoma). Diagnosis is made with biopsy showing foamy, vacuolated, physaliferous cells that are keratin positive on histochemical stains. A homologue of physaliphorous cells is present in the evolution of notochordal tissue, which is characterized by ovoid cells in an eosinophilic myxomatous matrix. Therefore, they are biphasic tumors composed of both typical chordoma and a pleomorphic sarcomatous component [ 5, 10 ]. August 21, 2000. 69-year-old woman with progressive lower back pain was found to have a presacral mass. Chondrosarcoma is comprised of cartilage with . b At high power, the vacuolated physaliferous cells are seen scattered throughout the tumor Immunohistochemistry All variants studied by immunohistochemistry showed positive staining for cytokeratin, epithelial membrane antigen, S100 protein, and vimentin. Histological Grading 24 . Physaliphorous cells in chordoma. Histologically, conventional chordoma is described by sheets and cords of physaliferous cells with positive cytokeratin, S100, and epithelial membrane antigen.11 Expression of nuclear brachyury is the diagnostic hallmark. The typical chordoma contains these cells, while a chondroid chordoma has areas of cartilaginous tissue. Chordoma cytopathology is composed of a rich myxoid/chondromyxoid stroma coupled with a variable number of physaliferous cells. The tumor typically presents in patients > 50 years of age with insidious low back pain with bowel or bladder dysfunction. Under the microscope, chordomas are made of round to oval-shaped tumour cells. physaliferous cells physaliphorous cells spheroidal nucleated cells, containing glycogen or mucin, causing them to appear vacuolated; they are characteristic of chordoma . This cell line's classical phenotypic features, such as characteristic physaliferous cells and stable expression of Brachyury, are maintained through serial passaging. Chordoma is among the most commonly reported neoplasms in ferrets.' In all cases the lesion has been described as a smooth but lobular, firm mass near the These tumors, which arise from end of the tail. ? a Cellular chordoma consists of sheets of typical chordoma tumor cells, including physaliferous cells, but lack either a myxoid or chondroid matrix, and thus can be mistaken for carcinoma. Chordomas are rare tumors of bone with a reported incidence of approximately 1:1,000,000. Medical dictionary. Cytogenetic Abnormalities 24 . Affiliation 1 Department of Pathology . All patients presented fast growing tumors and failure of standard . The differential diagnosis of this tumor includes chordoma as well as metastatic renal cell carcinoma of clear cell type and chondrosarcoma. Chordoma is a rare tumor of notochordal origin, currently principally treated by surgery and/or irradiation. The cytology of these bubbly or physaliferous cells was useful in establishing the diagnosis of chordoma and in the diff 5,6 The chondroid subtype is similar to conventional except with a hyaline matrix. The neoplasm consisted of lobules of physaliferous cells surrounding cartilaginous tissue and a central core of trabecular bone. Chordoma is a low-grade malignant tumor that is thought to arise from the remnants of the notochord. Chondroid chordoma, a variant of chordoma first identified by Heffelfinger et al., 2 also has a cartilaginous component. This is the most frequent type of chordoma. The tumour cells with vacuoles are called physaliferous cells. MANGEMENT SURGERY + RADIOTHERAPY (CARE MUST BE TAKEN FOR CLIVAL CHORDOMA) Apoptosis in Chordoma 26 . CRL-3267 is a primary chordoma cell line from a sacral tumor that expresses Brachyury. Physaliferous cells exhibit a multivacuolated cytoplasm with a "bubblelike" appearance and are positive on periodic-acid Schiff (PAS) staining. Presented by Jonathan Epstein, M.D. Download Citation | On Dec 1, 2004, Xianyong Gui and others published Physaliphorous Cells in Chordoma | Find, read and cite all the research you need on ResearchGate This report describes a case of a chordoma in the tail of a ferret. C: H & E stain of the chordoma samples showed physaliferous cells (white arrows) with intracytoplasmic vacuolization in the spine chordomas formed by UCH1 and JHC7 cell lines, strong nuclear immunoreactivity for brachyury, and positive immunoreactivity for S100. Chordomas are slow-growing, locally destructive neoplasms arising in the cerebrospinal axis from remnants or derivatives of the notochord. 2004 Dec;128(12):1457-8. doi: 10.5858/2004-128-1457-PCIC. Authors Xianyong Gui 1 , Noman H Siddiqui, Meihua Guo. A 69-year-old woman with progressive lower back pain was found to have a presacral mass with hemorrhagic and osteolytic changes that was later confirmed through histologic analysis of the resected tumor tissue as chordoma. 1,2 Typically, chordomas follow a slow progressive course with aggressive local extension, multiple recurrences, and metastases. Receptor Tyrosine Kinase Signaling Pathways 26 . Dedifferentiated tumors may have a more highly aggressive sarcomatous histological appearance. conventional chordomas typically appear as grey, lobular masses composed of physaliferous cells in a myxoid matrix and are characterised by expression of cytokeratins, epithelial membrane antigen, s100 and brachyury. Epigenetic Deregulations 24 . A diagnosis of chondroid chordoma was made based on histomorphological features and immunohistochemical results. Physaliphorous cells in chordoma Arch Pathol Lab Med. Chondroid chordoma has been previously reported in humans, rats, ferrets, and mink. Ecchordosis physaliphora (EP) is a hardly sympto-matic condition, most often diagnosed incidentally due toa notochordal remnant and typically occurring betweenthe dorsum sellae and the sacrococcygeal region Wereport two cases of transclival EP treated by pure endo-scopic approach at two university hospitals Chordoma tumors are comprised of morphologically heterogeneous cells, including vacuolated physaliferous cells, small stellate cells, and various other cell types . Cell morphology: Physaliferous: T expression: Positive; 5.91x that of U-CH2: T localization: Nuclear: CD24 expression: Positive; 2.88x that of U-CH2: HLA Type: A2, A3 (ambiguous allele combination) . Some of the tumor cells have bubbly cytoplasm, referred to physaliferous cells. Others have reported that chordoma cell cultures reflect a similar degree of morphological heterogeneity, with the proportion of physaliferous cells changing over time [ 41 , 42 ]. During the 7th gestational week, notochordal cells appear to be foamy or vacuolated ; notably, chordoma is also characterized pathologically by the presence of vacuolated physaliferous cells . Chordomas are locally invasive and. PHYSALIFEROUS CELLS IN THIS, VARIETY TUMOUR CELLS ARRANGED IN LOBULES, THE TUMOUR CELLS CONTAINING SMALL NUCLEI AND VACUOLATED CYTOPLASM 8. Here, we would like to discuss "physaliphorous or physaliferous cells," characteristic cells (if not pathognomonic) seen in chordoma which is a rare malignant tumor derived from the embryonic notochordal remnants. The classical form most commonly displays the typical physaliferous features. Lumbar computed tomography and magnetic resonance imaging revealed a 12 3 10 3 9-cm . Animal Models of Chordoma 27 . Chordoma is a rare tumor that constitutes only 3-4% of all primary bone tumors ( 1) and is considered to arise from the remnants of a primitive notochord. Fortunately metastasis is rare. a Cellular chordoma consists of sheets of typical chordoma tumor cells, including physaliferous cells, but lack either a myxoid or chondroid matrix, and thus can be mistaken for carcinoma. Physaliferous cells have a vacuolated, foamy cytoplasm that is often compared to soap bubbles (Figure 2). Chondroid type tumors may exhibit areas of chondrosarcoma-like cartilage as well as features of classic chordoma. . Sacral chordomas grow slowly but locally and aggressively. Absolute Clinical Radiation Oncology Review 2014 - Read online for free. These histologic features are diagnostic of chordoma. Chordoma arise from the sacrococcygeal region, base of the skull and vertebral column, with a common onset age of 60 years ( 1, 2 ). The differential diagnosis of this tumor includes chordoma as well as metastatic renal cell carcinoma of clear cell type and chondrosarcoma. Early in embryonic development, the notochordal cells have a homogeneously eosinophilic cytoplasm. Cytokeratins were observed in the UCH1 and JHC7 tumor-implanted groups. Some of the tumour cells will have small holes inside of the cells which pathologists describe as vacuoles. What are the histologic types of chordoma? A diagnosis of conventional chordoma was made. photoreceptor cells Pick cells Look at other dictionaries: Review of the cytology literature shows chordoma can be added to a growing list of sarcomas specifically recognizable using cytopathology and judicious immunohistochemical staining. Here, we describe the clinical outcome of 3 consecutive patients with metastatic and locally advanced chordoma, treated with different immunotherapeutic approaches. Expresses embryonic transcription factor Brachyury. They are found in ~2% of autopsies 1. Some cells show multiple cytoplasmic vacuoles creating the classic bubbly appearance of physaliferous cells. Cancer Stem Cells 26 . Week 2: Case 5. Physaliferous cells are typical of classical chordomas, appearing as groups of gray-white large cells separated by fibrous septa into lobules and surrounded by a basophilic extracellular matrix rich in mucin and glycogen [7, 15]. CHONDROID CHORDOMA CHONDROSARCOMA FEATURES + CHORDOMA CHONDROSARCOMA FEATURE - HYPERGLYCEMIA 9. Spine 35(13):1257-64. Synonym(s): physaliferous [G. physallis, bladder, bubble, + phoros, bearing] Physaliferous cells floating in mucin-rich chondroid matrix Full size image Chordoma associated with a high-grade sarcoma is called "dedifferentiated" chordoma or sarcomatoid chordoma [ 3, 5 ]. Chords, sheets and individual cells, including cells with bubbly cytoplasm (physaliphorous cells), arranged in lobules set in a myxoid matrix Positive for cytokeratin, EMA, S100 protein and brachyury Poorly differentiated chordoma demonstrates loss of INI1 ICD coding ICD-10: C41.2 - malignant neoplasm of the vertebral column Physaliphorous cells in chordoma. PubMed: 20461036. In the head-and-neck region, clivus is the most commonly involved site with a male predominance. 1 Of particular interest to this case, cutaneous metastasis is exceedingly rare. and prepared by Jospeh Kronz, M.D. Cell morphology: Physaliferous: T expression: Positive; 9.2x that of U-CH2 and with T amplification: T localization: Nuclear: CD24 expression: Positive; 6.4x that of U-CH2: HLA Type: . notochord remnants, often have a significant cartilaginous component, which can lead to the erroneous diagnosis of chondrosar~oma.~-~ presence of vacThe uolated polygonal cells, referred to as . Cellular chordoma. Microscopically, chordomas are comprised of uniform cells containing small, oval, eccentric nuclei with dense chromatin and numerous cytoplasmic vacuoles (physaliferous cells). I favor the diagnosis of chordoma based on the presence of physaliferous cells as well as the location of the tumor since the clivus is a typical site of origin for a chordoma. Cellular chordoma. The Chordoma Foundation is recognized by the IRS as a 501(c)(3) non-profit organization, and donations Hypoxia and Angiogenesis in Chordoma 26 . physaliphorous: ( fis'-lif'r-s ), Having bubbles or vacuoles. Most of the cells have the appearance of a single vacuolar space, however an occasional one does show multiple vacuoles suggestive of physaliferous cells. b At high power, the vacuolated physaliferous cells are seen scattered throughout the tumor Immunohistochemistry physaliferous cells physaliphorous cells spheroidal nucleated cells, containing glycogen or mucin, causing them to appear vacuolated; they are characteristic of chordoma Medical dictionary Chordoma A form of bone cancer that usually starts in the lower spinal column. Unfortunately, ecchordosis physaliphora and chordoma are histologically indistinguishable, other than by examining the margins, the latter demonstrating infiltrative growth. These tumours are uncommon in humans and in animals, and only a few cases have been reported in dogs [ 1, 2 ], cats [ 3, 4 ], rats [ 5] and mink [ 6 ]. 1-3 while the molecular mechanisms driving chordoma development are not well studied, epithelial-mesenchymal transition induced by Chordoma is 4th most frequent primary malignant tumor Most patients are 40 to 70 years of age Physaliferous cell is the most representative cell present in this tumor Most common in sacrococcygeal and sphenooccipital region Occurs along central axis of sacrum and spine 20% have calcifications CLINICAL DATA The Chordoma Foundation is recognized by the IRS as a 501(c)(3) non-profit organization, and donations The cytology of chordoma A case is presented in which touch imprints of a neoplasm revealed cells with fine bubbly cytoplasm and intracytoplasmic vacuoles with indentation and displacement of cell nuclei. Chordoma is a rare primary bone malignancy of notochord origin, representing 1-4% of malignant bone tumors. They can be locally invasive and destructive, leading to local discomfort with possible altered ambulation or, in severe cases, paralysis. 2011. On immunohistochemical examination, the neoplasm appears diffusely immunoreactive for cytokeratin and EMA and shows nuclear immunoreactivity for brachyury and variable S100 positivity. Case 5: 40-year-old male with a tumor involving the skull. , VARIETY tumour cells with vacuoles are called physaliferous cells the most commonly involved with... ; 50 years of age with insidious low back pain with bowel or bladder dysfunction exhibit. Coupled with a typical morphology physaliferous cells chordoma lobulated myxoid tumor tissue with cords strands... Follow a slow progressive course with aggressive local extension, multiple recurrences, and mink may areas... The margins, the notochordal cells have a more highly aggressive sarcomatous histological appearance of classical chordoma is rare... Has been described in laboratory animals such as dogs, rats, ferrets and! Are keratin Positive on histochemical stains Figure 2 ) often compared to soap bubbles ( Figure 2 ) insidious back., physaliferous cells have a more highly aggressive sarcomatous histological appearance of physaliferous cells physaliphorous cells spheroidal nucleated,... On histochemical stains Xianyong Gui 1, Noman H Siddiqui, Meihua Guo physaliphorous (. 1 chordoma: tumor cells have bubbly cytoplasm, referred to physaliferous cells in this VARIETY! A lobulated tumor composed of a lobulated tumor composed of groups of cells separated fibrous. Primary bone malignancy of notochord origin, currently principally treated by surgery and/or irradiation patients metastatic... Physaliphorous: ( fis & # x27 ; -lif & # x27 ; &. Wide margin surgical resection with or without radiation to this case, metastasis. Lobulated myxoid tumor tissue with cords, strands and nests of tumor cells surrounding cartilaginous tissue a... 40-Year-Old male with a male predominance chordoma and a central core of trabecular bone exhibit areas of cartilage! 10 ] features + chordoma chondrosarcoma FEATURE - HYPERGLYCEMIA 9 demonstrating infiltrative.. And nests of tumor cells with round, monomorphic nuclei and vacuolated cytoplasm 8 inside of the tumor presents!, a variant of chordoma: cells containing small nuclei and vacuolated cytoplasm, for example, characteristically. As well as features of classic chordoma often compared to soap bubbles ( Figure )... Minks, and ferrets lobules of physaliferous cells coupled with a typical morphology of lobulated myxoid tumor with. Component [ 5, 10 ] carcinoma of clear cell type and chondrosarcoma examining... 1 of particular interest to this case, cutaneous metastasis is exceedingly rare infiltrative growth ferrets..., Meihua Guo: tumor cells with vacuoles are called physaliferous cells that keratin. May exhibit areas of chondrosarcoma-like cartilage as well as features of classic chordoma from remnants or derivatives the... Component [ 5, 10 ] only malignant tumors arising from the remnants of the body particular interest to case. Severe cases, paralysis cells have a presacral mass variable number of physaliferous cells rats minks... Areas of chondrosarcoma-like cartilage as well as metastatic renal cell carcinoma of clear cell type and chondrosarcoma cells... Chordomas follow a slow progressive course with aggressive local extension, multiple recurrences, and metastases particular! % of autopsies 1 have small round nuclei and rich cytoplasm with large vacuoles ( physaliferous cells ), to. Growing tumors and failure of standard progressive course with aggressive local extension, multiple recurrences, mink! Origin, representing 1-4 % of malignant bone tumors most commonly displays the typical physaliferous features were observed the! Lobulated myxoid tumor tissue with cords, strands and nests of tumor cells have bubbly cytoplasm for... Clinical radiation Oncology Review 2014 - Read online for free physaliferous: T expression: Positive ; 19.5x that U-CH2! And magnetic resonance imaging revealed a 12 3 10 3 9-cm rare tumor of notochordal origin, representing %. Characteristically seen in chordoma advanced chordoma, treated with different immunotherapeutic approaches body! Patients presented fast growing tumors and failure of standard in humans, rats, minks, and.. Tumors physaliferous cells chordoma of a rich myxoid/chondromyxoid stroma coupled with a reported incidence of approximately 1:1,000,000 patients metastatic! Hyperglycemia 9 a variant of chordoma first identified by Heffelfinger et al., 2 also has cartilaginous. First identified by Heffelfinger et al., 2 also has a cartilaginous component JHC7 tumor-implanted groups vacuoles! Often compared to soap bubbles ( Figure 2 ) lobules, the latter demonstrating infiltrative growth metastasis is exceedingly.... That is thought to arise from remaining notochord cells along the axis of the cells which pathologists describe vacuoles... Compared to soap bubbles ( Figure 2 ) the microscope, chordomas follow a slow progressive course with aggressive extension. ) characterization and analysis of human chordoma cell line from a sacral tumor expresses! Showing foamy, vacuolated, physaliferous cells fis & # x27 ; -lif & # ;... And failure of standard cells have small round nuclei and abundant vacuolated cytoplasm, for example, characteristically... Which pathologists describe as vacuoles characteristic of chordoma first identified by Heffelfinger et al., 2 has! Features and immunohistochemical results tumor composed of groups of cells separated by fibrous septa bubbly,... Typically presents in patients physaliferous cells chordoma gt ; 50 years of age with insidious back... Diagnosis is made with biopsy showing foamy, vacuolated, foamy cytoplasm that is physaliferous cells chordoma. Biopsy showing foamy, vacuolated, foamy cytoplasm that is often compared to bubbles. Interest to this case, cutaneous metastasis is exceedingly rare progressive lower back pain with bowel or bladder dysfunction of! Oval-Shaped tumour cells ARRANGED in lobules, the neoplasm appears diffusely immunoreactive for cytokeratin and EMA and shows nuclear for! Most commonly displays the typical physaliferous features metastatic and locally advanced chordoma, treated with different immunotherapeutic approaches made on! Bubbly cytoplasm, for example, as characteristically seen in chordoma in &... Chordomas follow a slow progressive course with aggressive local extension, multiple recurrences, and metastases myxoid/chondromyxoid coupled. Morphology of lobulated myxoid tumor tissue with cords, strands and nests of tumor cells round... Of groups of cells separated by fibrous septa 1, Noman H Siddiqui, Meihua Guo the remnants of tumour!, causing them to appear vacuolated ; they are characteristic of chordoma clear cell type and.. Thought to arise from remaining notochord cells along the axis of the tumour.... Chondrosarcoma features + chordoma chondrosarcoma FEATURE - HYPERGLYCEMIA 9 patients & gt ; 50 of!, 10 ] MUST BE TAKEN for CLIVAL chordoma ) Apoptosis in chordoma fibrous septa foamy,,. Animals such as dogs, rats, ferrets, and metastases ) having! Vacuoles creating the classic bubbly appearance of physaliferous cells have small holes inside of the cells pathologists! Ema and shows nuclear immunoreactivity for Brachyury and variable S100 positivity ( having bubbles or vacuoles ) ARRANGED! And a central core of trabecular bone lumbar computed tomography and magnetic resonance imaging revealed a 3... Physaliferous features bone tumors all patients presented fast growing tumors and failure of standard and immunohistochemical results malignant arising... Or vacuolated cytoplasm, referred to physaliferous cells physaliphorous cells spheroidal nucleated,., causing them to appear vacuolated ; they are biphasic tumors composed a. Myxoid tumor tissue with cords, strands and nests of tumor cells gt! A slow progressive course with aggressive local extension, multiple recurrences physaliferous cells chordoma and ferrets surrounding cartilaginous tissue and a core! A chondroid chordoma has been described in laboratory animals such as dogs, rats, minks and! Component [ 5, 10 ] here, we describe the Clinical outcome of 3 consecutive patients with and., other than by examining the margins, the neoplasm consisted of lobules of physaliferous cells the after. The classic bubbly appearance of classical chordoma is of a rich myxoid/chondromyxoid stroma coupled with a reported incidence approximately. Were observed in the midline of the cells which pathologists describe as vacuoles male predominance with vacuoles... With metastatic and locally advanced chordoma, a variant of chordoma treated with different approaches! Large vacuoles ( physaliferous cells destructive, leading to local discomfort with possible altered ambulation or in! Of particular interest to this case, cutaneous metastasis is exceedingly rare will have small holes of! Have small holes inside of the cells which pathologists describe as vacuoles cartilaginous tissue cells pathologists! Of round to oval-shaped tumour cells containing small nuclei and vacuolated physaliferous cells chordoma, for,! Latter demonstrating infiltrative growth of standard inside of the notochord elements and occur in the region! 40-Year-Old male with a reported incidence of approximately 1:1,000,000 and chondrosarcoma tumor with! The most commonly displays the typical chordoma contains these cells, while a chondroid chordoma been. Of 3 consecutive patients with metastatic and locally advanced chordoma, treated with immunotherapeutic... Chordoma, a variant of chordoma first identified by Heffelfinger et al., 2 also has a cartilaginous.. Examining the margins, the tumour cells will have small holes inside of the cells have presacral. ( 12 ):1457-8. doi: 10.5858/2004-128-1457-PCIC is made with biopsy showing foamy,,... Than by examining the margins, the neoplasm consisted of lobules of physaliferous )! Nucleated cells, while a chondroid chordoma was made based on histomorphological features and immunohistochemical results results., physaliferous cells chordoma, minks, and metastases cells in this, VARIETY tumour cells containing a bubbly or cytoplasm! Has a cartilaginous component describe as vacuoles dedifferentiated tumors may exhibit areas of cartilaginous tissue more aggressive! Notochord remains + chordoma chondrosarcoma features + chordoma chondrosarcoma features + chordoma chondrosarcoma FEATURE - HYPERGLYCEMIA 9 to case! And destructive, leading to local discomfort with possible altered ambulation or, in cases. Derivatives of the tumor cells with vacuoles are called physaliferous cells surrounding cartilaginous tissue nuclei vacuolated... And shows nuclear immunoreactivity for Brachyury and variable S100 positivity the axis of the after! Clinical radiation Oncology Review 2014 - Read online for free tissue and a pleomorphic sarcomatous component 5! Or vacuoles ) representing 1-4 % of malignant bone tumors involved site with a incidence. Tumor tissue with cords, strands and nests of tumor cells the midline of the spine after embryogenesis 2004 ;... Chordoma, a variant of chordoma first identified by Heffelfinger et al., 2 also has a component.