Chordoma and chondroid neoplasms of the spheno-occiput. An immunohistochemical study of 41 cases with prognostic and nosologic implications

An experience in treatment of neurologically silent clival chordoma mimicking a nasopharyngeal tumor

Cranial chordoma is a rare neoplasm that is challenging to both diagnose and manage. We present our experience in treating a case of clival chordoma mimicking a nasopharyngeal mass without any signs of cranial deficits or intracranial insult. Management was comprised of endoscopic transnasal debulking surgery followed by radiotherapy. However, we failed to achieve an oncologic outcome due to the development of lethal central nervous system and respiratory infections 1 month after the surgery.

Efficacy and safety of carbon ion radiotherapy for chordomas: a systematic review and meta-analysis

OBJECTIVE

Carbon ion radiotherapy (C-ion RT) for chordomas has been gradually performed in several research centres. This study aimed to systematically review the results of clinical reports from these institutions and to evaluate the safety and efficacy of C-ion RT.

METHODS

In accordance with the PRISMA guidelines and set search strategies, we searched four databases for articles from their inception to February 11, 2023. These articles were screened, and data were extracted independently by two researchers. STATA 14.0 was used for statistical analysis of survival results.

RESULTS

A total of 942 related articles were retrieved, 11 of which were included. Regarding lesion location, 57% (n = 552) originated in the sacral region, 41% (n = 398) in the skull base, and 2% (n = 19) in the spine (upper cervical). The local control (LC) rates at 1, 2, 3, 5, 9, and 10 years in these studies were 96%, 93%, 83%, 76%, 71%, and 54%, respectively. The overall survival (OS) rates at 1, 2, 3, 5, 9, and 10 years in these studies were 99%, 100%, 93%, 85%, 76%, and 69%, respectively. Acute and late toxicities were acceptable, acute toxicities were mainly grade 1 to grade 2 and late toxicities were mainly grade 1 to grade 3.

CONCLUSION

C-ion RT has attractive clinical application prospects and is an important local treatment strategy for chordomas. Encouraging results were observed in terms of LC and OS. Meanwhile, the acute and late toxicities were acceptable. PROSPERO registration number: CRD42023398792.

Proton and carbon ion beam treatment with active raster scanning method in 147 patients with skull base chordoma at the Heidelberg Ion Beam Therapy Center-a single-center experience

BACKGROUND

This study aimed to compare the results of irradiation with protons versus irradiation with carbon ions in a raster scan technique in patients with skull base chordomas and to identify risk factors that may compromise treatment results.

METHODS

A total of 147 patients (85 men, 62 women) were irradiated with carbon ions (111 patients) or protons (36 patients) with a median dose of 66 Gy (RBE (Relative biological effectiveness); carbon ions) in 4 weeks or 74 Gy (RBE; protons) in 7 weeks at the Heidelberg Ion Beam Therapy Center (HIT) in Heidelberg, Germany. The median follow-up time was 49.3 months. All patients had gross residual disease at the beginning of RT. Compression of the brainstem was present in 38%, contact without compression in 18%, and no contact but less than 3 mm distance in 16%. Local control and overall survival were evaluated using the Kaplan-Meier Method based on scheduled treatment (protons vs. carbon ions) and compared via the log rank test. Subgroup analyses were performed to identify possible prognostic factors.

RESULTS

During the follow-up, 41 patients (27.9%) developed a local recurrence. The median follow-up time was 49.3 months (95% CI: 40.8-53.8; reverse Kaplan-Meier median follow-up time 56.3 months, 95% CI: 51.9-60.7). No significant differences between protons and carbon ions were observed regarding LC, OS, or overall toxicity. The 1‑year, 3‑year, and 5‑year LC rates were 97%, 80%, and 61% (protons) and 96%, 80%, and 65% (carbon ions), respectively. The corresponding OS rates were 100%, 92%, and 92% (protons) and 99%, 91%, and 83% (carbon ions). No significant prognostic factors for LC or OS could be determined regarding the whole cohort; however, a significantly improved LC could be observed if the tumor was > 3 mm distant from the brainstem in patients presenting in a primary situation.

CONCLUSION

Outcomes of proton and carbon ion treatment of skull base chordomas seem similar regarding tumor control, survival, and toxicity. Close proximity to the brainstem might be a negative prognostic factor, at least in patients presenting in a primary situation.

Metastatic chordoma with pancreatic disease and response to imatinib

A 45-year-old woman presented with a left-sided neck swelling following treatment a year prior for cervical spine chordoma. She had initially been managed surgically with a cervical vertebrectomy and a course of proton beam therapy. Although there had been a degree of residual tissue, her disease remained stable radiologically and clinically. Repeat MRI demonstrated an increasing left paravertebral mass and a head of pancreas metastasis, which shared pathological characteristics with chordoma. Given the advanced metastatic nature of her disease, imatinib was offered with a palliative intent. While waiting for treatment she developed a spinal cord compression, managed with radiotherapy. She commenced imatinib and her disease remained stable for 9 months before progressing clinically and radiologically. This case demonstrates an unusual pattern of metastatic chordoma and provides further rationale for imatinib in such patients.

Chordoma: Current status, problems, and future directions

Chordoma is a rare tumor that occurs along the axial spine in pediatrics and adults, with an incidence of approximately 350 cases per year in the United States. While typically described as slow-growing, many patients will eventually develop loco-regional relapse or metastatic disease with few treatment options. Despite numerous efforts over the last 10+ years, effective treatments for patients are lacking. As subtypes of chordoma are identified and described in more detail, further knowledge regarding the natural history of each type, tumor location, age differences, genomic variability, and an overall better understanding of chordoma may be the key to developing meaningful clinical trials and effective therapies for patients with chordoma.

Endoscope-Assisted Middle Fossa Approach: Optimizing the Surgical Corridor for the Resection of Multicompartmental Chordomas

Background  Skull base chordomas are a major therapeutic challenge. The surgical management involves selecting an approach that will offer the patient the best chance of largest/complete removal while minimizing morbidity and mortality. Methods  Medical records and imaging review of two skull base chordomas involving the middle fossa and posterior fossa that were successfully treated with an endoscope-assisted middle fossa approach. Results  The use of angled endoscopes provided better identification of anatomical landmarks and improved tumor resection when compared with the microscopic surgical exposure. The approach selection, anatomical landmarks, and technical aspects of the intraoperative setting of the endoscope-assisted approach are discussed. Conclusion  Endoscopic assistance in the middle fossa approach is a safe and valuable tool for maximizing the reach of the surgical corridor when treating skull base chordomas.

Surgery of the lateral skull base: a 50-year endeavour

Disregarding the widely used division of skull base into anterior and lateral, since the skull base should be conceived as a single anatomic structure, it was to our convenience to group all those approaches that run from the antero-lateral, pure lateral and postero-lateral side of the skull base as “Surgery of the lateral skull base”. “50 years of endeavour” points to the great effort which has been made over the last decades, when more and more difficult surgeries were performed by reducing morbidity. The principle of lateral skull base surgery, “remove skull base bone to approach the base itself and the adjacent sites of the endo-esocranium”, was then combined with function preservation and with tailoring surgery to the pathology. The concept that histology dictates the extent of resection, balancing the intrinsic morbidity of each approach was the object of the first section of the present report. The main surgical approaches were described in the second section and were conceived not as a step-by-step description of technique, but as the highlighthening of the surgical principles. The third section was centered on open issues related to the tumor and its treatment. The topic of vestibular schwannoma was investigated with the current debate on observation, hearing preservation surgery, hearing rehabilitation, radiotherapy and the recent efforts to detect biological markers able to predict tumor growth. Jugular foramen paragangliomas were treated in the frame of radical or partial surgery, radiotherapy, partial “tailored” surgery and observation. Surgery on meningioma was debated from the point of view of the neurosurgeon and of the otologist. Endolymphatic sac tumors and malignant tumors of the external auditory canal were also treated, as well as chordomas, chondrosarcomas and petrous bone cholesteatomas. Finally, the fourth section focused on free-choice topics which were assigned to aknowledged experts. The aim of this work was attempting to report the state of the art of the lateral skull base surgery after 50 years of hard work and, above all, to raise questions on those issues which still need an answer, as to allow progress in knowledge through sharing of various experiences. At the end of the reading, if more doubts remain rather than certainties, the aim of this work will probably be achieved.

Prognostic Implications of Gadolinium Enhancement of Skull Base Chordomas

BACKGROUND AND PURPOSE

Skull base chordomas often demonstrate variable MR imaging characteristics, and there has been limited prior research investigating the potential clinical relevance of this variability. The purpose of this retrospective study was to assess the prognostic implications of signal intensity on standard imaging techniques for the biologic behavior of skull base chordomas.

MATERIALS AND METHODS

Medical records were retrospectively reviewed for 22 patients with pathologically confirmed skull base chordomas. Clinical data were recorded, including the degree of surgical resection, the presence or absence of radiation therapy, and time to progression/recurrence of the tumor or time without progression/recurrence of the tumor following initial treatment. Pretreatment imaging was reviewed for the presence or absence of enhancement and the T2 signal characteristics. Tumor-to-brain stem signal intensity ratios on T2, precontrast T1, and postcontrast T1 spin-echo sequences were also calculated. Statistical analysis was then performed to assess correlations between imaging characteristics and tumor progression/recurrence.

RESULTS

Progression/recurrence of skull base chordomas was seen following surgical resection in 11 of 14 (78.6%) patients with enhancing tumors and in zero of 8 patients with nonenhancing tumors. There was a statistically significant correlation between skull base chordoma enhancement and subsequent tumor progression/recurrence (P < .001), which remained significant after controlling for differences in treatment strategy (P < .001). There was also a correlation between postcontrast T1 signal intensity (as measured by postcontrast T1 tumor-to-brain stem signal intensity ratios) and recurrence/progression (P = .02). While T2 signal intensity was higher in patients without tumor progression (median tumor-to-brain stem signal intensity ratios on T2 = 2.27) than in those with progression (median tumor-to-brain stem signal intensity ratios on T2 = 1.78), this association was not significant (P = .12).

CONCLUSIONS

Enhancement of skull base chordomas is a risk factor for tumor progression/recurrence following surgical resection.

Four-Level Vertebrectomy for En Bloc Resection of a Cervical Chordoma

BACKGROUND

Chordomas are locally aggressive tumors that can involve multiple levels of the spine and are difficult to resect. We present our technique for 4-level en bloc cervical spondylectomy for a locally aggressive chordoma.

CASE DESCRIPTION

A 37-year-old woman presented with a 6-month history of dysphagia and a large indurated cervical mass. Imaging showed an enhancing lesion involving C3-6. Needle biopsy confirmed the diagnosis of chordoma. En bloc resection was chosen to maximize her chances of disease-free survival. A 360° approach was deemed necessary. We posteriorly disconnected the vertebral bodies and skeletonized the bilateral vertebral arteries and nerve roots. The interspinous and yellow ligaments and the spinous processes were spared to maintain a solid posterior tension band, as previously described approaches that had sacrificed these elements had a high rate of instrumentation failure. After posterior instrumentation, a wide anterior approach enabled us to resect the tumor attached to the vertebral bodies of C3-6 as 1 specimen. A 4-level corpectomy cage and plate were used for anterior instrumentation. The patient tolerated the surgery well. She needed a temporary gastrostomy, and she had a right C5 palsy that progressively recovered. Follow-up imaging showed no tumor recurrence and good bony fusion.

CONCLUSIONS

En bloc resection as part of a multidisciplinary team approach remains the mainstay of spinal chordoma treatment. Modern instrumentation and careful dissection can provide good results even in locally advanced cases.

Gamma Knife Management of Skull Base Chordomas: Is it a Choice?

Background:

Skull base chordomas are locally invasive tumors which able to extend in different directions with skull base invasion. Although they are histologically benign, they have invasive nature makes total resection virtually impossible to achieve in most cases and this lead to residual tumors after surgery. To decrease postoperative surgical resection morbidity of these tumors, gamma knife radiosurgery (GKRS) was performed as alternative management for these residual chordomas to evaluate its safety and efficacy.

Materials and Methods:

A retrospective study was made on eight residual skull base chordomas treated with GKRS between 2011 and 2015. The mean patient age was 49 years (range 30–73 years). Four patients harboring chordoma were male, and four patients were females with 1:1 ratio. All patients had undergone one prior surgery. Patients were treated with peripheral dose ranged between 12–15 gray (Gy) (mean 13.75 Gy) usually at 35% to 50% isodose curve (mean 38.8%). The maximum dose to the adjacent brain stem area ranged between 10 and 12 Gy. All patients were followed up from 8 to 39 months (mean 18 months).

Results:

The tumor control rate was 50% and 25% after 18 and 36 months, respectively, but we found that their wasdeclined in the tumor control rate with long follow-up time. Four tumors were stable in their size just for 18 months, and then there two of these tumors were progressed in their size, the other four patients showed progression in their tumors in their 1^st year of treatment without sign of central tumor necrosis.

Conclusion:

Skull base chordoma patients complained from symptoms due to tumor mass effect which were not prospected to respond to GKRS alone as the aim of this type of treatment was the local tumor control, the tumor control rate declined with long follow-up time and this correlated with radioresistant nature of skull base chordoma. We advise a gross total resection to decrease the tumor volume, and this making gamma knife a reasonable treatment modality.

Chordoma of the Head and Neck: A Review

Chordoma is a rare malignant bone tumor that can arise anywhere along the central neural axis and many involve head and neck sites, most commonly the skull base. The relative rarity of these tumors, combined with the complex anatomy of the head and neck, pose diagnostic challenges to pathologists. This article describes the pertinent clinical, pathologic, and molecular features of chordomas and describes how these features can be used to aid in formulating a differential diagnosis. Emphasis is placed on key diagnostic pitfalls and the importance of incorporating immunohistochemical information into the diagnosis.

Multidisciplinary management of clival chordomas; long-term clinical outcome in a single-institution consecutive series

OBJECTIVE

Chordomas of the skull base have high recurrence rates even after radical resection and adjuvant radiotherapy. We evaluate the long-term clinical outcome using multidisciplinary management in the treatment of clival chordomas.

METHODS

Between 1984 and 2015, 22 patients diagnosed with an intracranial chordoma were treated at the Karolinska University Hospital, Stockholm, Sweden. Sixteen of 22 were treated with Gamma Knife radiosurgery (GKRS) for tumour residual or progression during the disease course. Seven of 22 received adjuvant fractionated radiotherapy and 5 of these also received proton beam radiotherapy.

RESULTS

Fifteen of 22 (68%) patients were alive at follow-up after a median of 80 months (range 22-370 months) from the time of diagnosis. Six were considered disease free after >10-year follow-up. The median tumour volume at the time of GKRS was 4.7 cm³, range 0.8-24.3 cm³. Median prescription dose was 16 Gy, range 12-20 Gy to the 40-50% isodose curve. Five patients received a second treatment with GKRS while one received three treatments. After GKRS patients were followed with serial imaging for a median of 34 months (range 6-180 months). Four of 16 patients treated with GKRS were in need of a salvage microsurgical procedure compared to 5/7 treated with conventional or proton therapy.

CONCLUSION

After surgery, 7/22 patients received conventional and/or photon therapy, while 15/22 were treated with GKRS for tumour residual or followed with serial imaging with GKRS as needed upon tumour progression. With this multidisciplinary management, 5- and 10-year survivals of 82% and 50% were achieved, respectively.

Distinctive Head and Neck Bone and Soft Tissue Neoplasms

Benign and malignant primary bone and soft tissue lesions of the head and neck are rare. The uncommon nature of these tumors, combined with the complex anatomy of the head and neck, pose diagnostic challenges to pathologists. This article describes the pertinent clinical, radiographic, and pathologic features of selected bone and soft tissue tumors involving the head and neck region, including angiofibroma, glomangiopericytoma, rhabdomyosarcoma, biphenotypic sinonasal sarcoma, chordoma, chondrosarcoma, and osteosarcoma. Emphasis is placed on key diagnostic pitfalls, differential diagnosis, and the importance of correlating clinical and radiographic information, particularly for tumors involving bone.

Update From The 4th Edition of the World Health Organization Classification of Head and Neck Tumours: Nasopharynx

The current WHO classification system for tumors of the head and neck has made few changes from the previous edition with regards to tumors of the nasopharynx. The classification system is discussed here with particular attention to nasopharyngeal carcinoma, nasopharyngeal papillary adenocarcinoma, salivary gland anlage tumor, hairy polyp, juvenile angiofibroma, and other tumors.

Whole-transcriptome analysis of chordoma of the skull base

Fourteen skull base chordoma specimens and three normal specimens were microdissected from paraffin-embedded tissue. Pools of RNA from highly enriched preparations of these cell types were subjected to expression profiling using whole-transcriptome shotgun sequencing. Using strict criteria, 294 differentially expressed transcripts were found, with 28 % upregulated and 72 % downregulated. The transcripts were annotated using NCBI Entrez Gene and computationally analyzed with the Ingenuity Pathway Analysis program. From these significantly changed expressions, the analysis identified 222 cancer-related transcripts. These 294 differentially expressed genes and non-coding RNA transcripts provide here a set to specifically define skull base chordomas and to identify novel and potentially important targets for diagnosis, prognosis, and therapy of this cancer. Significance Genomic profiling to subtype skull base chordoma reveals potential candidates for specific biomarkers, with validation by IHC for selected candidates. The highly expressed developmental genes T, LMX1A, ZIC4, LHX4, and HOXA1 may be potential drivers of this disease.

Long term outcomes of patients with skull-base low-grade chondrosarcoma and chordoma patients treated with pencil beam scanning proton therapy

PURPOSE

To evaluate the long term tumor control and toxicity of skull base tumors treated with pencil beam scanning proton therapy (PT).

MATERIALS AND METHODS

PT was delivered to 151 (68%) and 71 (32%) chordoma and chondrosarcoma (ChSa) patients, respectively. Mean age of patients was 40.8±18.4years and the male to female ratio was 0.53. The postoperative tumor was abutting the brainstem or optic apparatus in 71 (32.0%) patients. The postoperative mean gross tumor volume (GTV) was 35.7±29.1cm(3). The delivered mean PT dose was 72.5±2.2GyRBE.

RESULTS

After a mean follow-up of 50 (range, 4-176) months, 35 local (15.8%) failures were observed between 10.9 and 85.4months. The estimated 7-year LC rate for chordoma (70.9%; CI95% 61.5-81.8) was significantly lower compared to the LC rate for ChSa patients (93.6%; 95%CI 87.8-99.9; P=0.014). The estimated 7-year distant metastasis-free- and overall survival rate was 91.6% (95%CI 91.6-98.6) and 81.7% (95%CI 74.7-89.5), respectively. On multivariate analysis, optic apparatus and/or brainstem compression, histology and GTV were independent prognostic factors for LC and OS. The 7-year high grade toxicity-free survival was 87.2 (95%CI 82.4-92.3).

CONCLUSIONS

PBS PT is an effective treatment for skull base tumors with acceptable late toxicity. Optic apparatus and/or brainstem compression, histology and GTV allow independent prediction of the risk of local failure and death in skull base tumor patients.

Chordoma: The Quest for Better Treatment Options

Chordoma is an extremely rare cancer, with an incidence of about one case per million persons per year in the USA and Europe (about 300 and 450 cases per year, respectively). The estimated median overall survival of patients with chordoma is approximately 6–7 years, yielding a rough estimate of chordoma prevalence at about 2000 in the USA and 3000 in Europe. Primary tumor develops along the axial spine between the clivus and sacrum and develops from the residual embryonic notochord. Brachyury (T), a transcription factor required for normal embryonic development, is expressed in the notochord and overexpressed in almost all cases of chordoma. The primary treatment for chordoma is surgical excision with wide local margins, when possible. Radiotherapy also plays a significant role in the adjuvant setting and when surgery is not possible. Unfortunately, in the advanced and/or metastatic setting, where the role of surgery and/or radiation is less clear, treatment options are very limited. To date, there have been no randomized, controlled trials in chordoma that have resulted in defined agents of clinical benefit for systemic treatment. This review briefly describes the natural history and initial treatment of chordoma and focuses on treatment options for advanced disease and potential avenues of research that may lead to improved treatment options in the future.

Paediatric Chordomas

Paediatric chordomas are rare malignant tumours arising from primitive notochordal remnants with a high rate of recurrence. Only 5 % of them occur in the first two decades such less than 300 paediatric cases have been reported so far in the literature. In children, the average age at diagnosis is 10 years with a male-to-female ratio closed to 1. On the opposite to adults, the majority of paediatric chordomas are intracranial, characteristically centered on the sphenooccipital synchondrosis. Metastatic spread seems to be the prerogative of the under 5-year-old children with more frequent sacro-coccygeal locations and undifferentiated histology. The clinical presentation depends entirely on the tumour location. The most common presenting symptoms are diplopia and signs of raised intracranial pressure. Sacrococcygeal forms may present with an ulcerated subcutaneous mass, radicular pain, bladder and bowel dysfunctions. Diagnosis is suspected on computerised tomography showing the bone destruction and with typically lobulated appearance, hyperintense on T2-weighted magnetic resonance imaging. Today, treatment relies on as complete surgical resection as possible (rarely achieved because of frequent invasiveness of functional structures) followed by adjuvant radiotherapy by proton therapy. The role of chemotherapy has not been proven. Prognosis is better than in adults and depends on the extent of surgical resection, age and histology subgroup. Biological markers are still lacking to improve prognosis by developing targeted therapy.

Nuances in the treatment of malignant tumors of the clival and petroclival region

Introduction Malignancies of the clivus and petroclival region are mainly chordomas and chondrosarcomas. Although a spectrum of malignancies may present in this area, a finite group of commonly encountered malignant pathologies will be the focus of this review, as they are recognized to be formidable pathologies due to adjacent critical neurovascular structures and challenging surgical approaches.

Objectives The objective is to review the literature regarding medical and surgical management of malignant tumors of the clival and petroclival region with a focus on clinical presentation, diagnostic identification, and associated adjuvant therapies. We will also discuss our current treatment paradigm using endoscopic, open, and combined approaches to the skull base.

Data Synthesis A literature review was conducted, searching for basic science and clinical evidence from PubMed, Medline, and the Cochrane Database. The selection criteria encompassed original articles including data from both basic science and clinical literature, case series, case reports, and review articles on the etiology, diagnosis, treatment, and management of skull base malignancies in the clival and petroclival region.

Conclusions The management of petroclival malignancies requires a multidisciplinary team to deliver the most complete surgical resection, with minimal morbidity, followed by appropriate adjuvant therapy. We advocate the combination of endoscopic and open approaches (traditional or minimally invasive) as required by the particular tumor followed by radiation therapy to optimize oncologic outcomes.

Chordoma: the entity

Chordomas are malignant tumors of the axial skeleton, characterized by their locally invasive and slow but aggressive growth. These neoplasms are presumed to be derived from notochordal remnants with a molecular alteration preceding their malignant transformation. As these tumors are most frequently observed on the skull base and sacrum, patients suffering from a chordoma present with debilitating neurological disease, and have an overall 5-year survival rate of 65%. Surgical resection with adjuvant radiotherapy is the first-choice treatment modality in these patients, since chordomas are resistant to conventional chemotherapy. Even so, management of chordomas can be challenging, as chordoma patients often present with recurrent disease. Recent advances in the understanding of the molecular events that contribute to the development of chordomas are promising; the most novel finding being the identification of brachyury in the disease process. Here we present an overview of the current paradigms and summarize relevant research findings.

Skull base chondroid chordoma: atypical case manifesting as intratumoral hemorrhage and literature review

OBJECTIVE

Chondroid chordoma (CC) is a rare but commonest subtype of chordoma with little reported clinical information. The present study summarizes and updates present knowledge of CC.

METHODS

Literature search for demographic data and clinical appearance of cranial CCs except for those entirely confined to the sinonasal region.

RESULTS

A total of 48 English language papers published from 1968-2013 were retrieved describing 132 CCs as skull base tumors. The male-to-female ratio was 1:1. The mean age at diagnosis was 43 years, predisposing to the third to fifth decades of life. The clival (34%) and spheno-occipital (29%) regions were the most frequent sites of origin followed by the sellar (12%) and sphenoid (5%) regions. Intratumoral calcification and bony erosion were identified as the characteristic neuroimaging findings. Surgical resection by the transcranial, transsphenoidal, transnasal, transpharyngeal, or transpalatal route with or without adjuvant radiotherapy was the main treatment option. The initial treatment outcome was satisfactory in 82% of cases with considerably better prognosis compared with typical chordomas.

CONCLUSION

CC is a distinct entity to be discriminated from the typical type of chordoma. There are no distinguishing features on magnetic resonance imaging between CC and typical chordoma. Intratumoral calcification and concurrent bony erosion on neuroimaging should suggest the possibility of CC. Extensive surgical resection and adjuvant radiotherapy can achieve satisfactory outcome.

[Chordoma]

PURPOSES

To review in the literature, all the epidemiological, clinical, radiological, histological and therapeutic data regarding chordomas as well as various notochordal entities: ecchordosis physaliphora, intradural and intraparenchymatous chordomas, benign notochordal cell tumors, parachordomas and extra-axial chordomas. To identify different types of chordomas, including familial forms, associations with tuberous sclerosis, Ollier's disease and Maffucci's syndrome, forms with metastasis and seeding. To assess the recent data regarding molecular biology and progress in targeted therapy. To compare the different types of radiotherapy, especially protontherapy and their therapeutic effects. To review the largest series of chordomas in their different localizations (skull base, sacrum and mobile spine) from the literature.

MATERIALS

The series of 136 chordomas treated and followed up over 20 years (1972-2012) in the department of neurosurgery at Lariboisière hospital is reviewed. It includes: 58 chordomas of the skull base, 47 of the craniocervical junction, 23 of the cervical spine and 8 from the lombosacral region. Similarly, 31 chordomas in children (less than 18 years of age), observed in the departments of neurosurgery of les Enfants-Malades and Lariboisière hospitals, are presented. They were observed between 1976 and 2010 and were located intracranially (n=22 including 13 with cervical extension), 4 at the craniocervical junction level and 5 in the cervical spine.

METHODS

In the entire Lariboisière series and in the different groups of localization, different parameters were analyzed: the delay of diagnosis, of follow-up, of occurrence of metastasis, recurrence and death, the number of primary patients and patients referred to us after progression or recurrence and the number of deaths, recurrences and metastases. The influence of the quality of resection (total, subtotal and partial) on the prognosis is also presented. Kaplan-Meier actuarial curves of overall survival and disease free survival were performed in the entire series, including the different groups of localization based on the following 4 parameters: age, primary and secondary patients, quality of resection and protontherapy. In the pediatric series, a similar analysis was carried-out but was limited by the small number of patients in the subgroups.

RESULTS

In the Lariboisière series, the mean delay of diagnosis is 10 months and the mean follow-up is 80 months in each group. The delay before recurrence, metastasis and death is always better for the skull base chordomas and worse for those of the craniocervical junction, which have similar results to those of the cervical spine. Similar figures were observed as regards the number of deaths, metastases and recurrences. Quality of resection is the major factor of prognosis with 20.5 % of deaths and 28 % of recurrences after total resection as compared to 52.5 % and 47.5 % after subtotal resection. This is still more obvious in the group of skull base chordomas. Adding protontherapy to a total resection can still improve the results but there is no change after subtotal resection. The actuarial curve of overall survival shows a clear cut in the slope with some chordomas having a fast evolution towards recurrence and death in less than 4 years and others having a long survival of sometimes more than 20 years. Also, age has no influence on the prognosis. In primary patients, disease free survival is better than in secondary patients but not in overall survival. Protontherapy only improves the overall survival in the entire series and in the skull base group. Total resection improves both the overall and disease free survival in each group. Finally, the adjunct of protontherapy after total resection is clearly demonstrated. In the pediatric series, the median follow-up is 5.7 years. Overall survival and disease free survival are respectively 63 % and 54.3 %. Factors of prognosis are the histological type (atypical forms), localization (worse for the cervical spine and better for the clivus) and again it will depend on the quality of resection.

CONCLUSIONS

Many different pathologies derived from the notochord can be observed: some are remnants, some may be precursors of chordomas and some have similar features but are probably not genuine chordomas. To-day, immuno-histological studies should permit to differentiate them from real chordomas. Improving knowledge of molecular biology raises hopes for complementary treatments but to date the quality of surgical resection is still the main factor of prognosis. Complementary protontherapy seems useful, especially in skull base chordomas, which have better overall results than those of the craniocervical junction and of the cervical spine. However, we are still lacking an intrinsic marker of evolution to differentiate the slow growing chordomas with an indolent evolution from aggressive types leading rapidly to recurrence and death on which more aggressive treatments should be applied.

Chondrosarcomas of the head and neck

Chondrosarcoma represents approximately 11% of all primary malignant bone tumors. It is the second most common sarcoma arising in bone after osteosarcoma. Chondrosarcomas of the head and neck are rare and may involve the sinonasal tract, jaws, larynx or skull base. Depending on the anatomical location, the tumor can produce a variety of symptoms. Computed tomography and magnetic resonance imaging are the preferred imaging modalities. The histology of conventional chondrosarcoma is relatively straightforward; major challenges are the distinction between grade I chondrosarcomas and chondromas, and the differential diagnosis with chondroblastic osteosarcoma and chondroid chordoma. Surgery alone or followed by adjuvant radiotherapy is the treatment of choice. Radiotherapy alone has also been reported to be effective and can be considered if mutilating radical surgery is the only curative alternative. The 5-year survival for chondrosarcoma reaches 80%; distant metastases and/or local recurrences significantly worsen prognosis. The present review aims to summarize the current state of information about the biology, diagnosis and management of these rare tumors.

Clival chordomas: A pathological, surgical, and radiotherapeutic review

BACKGROUND

The purpose of this study was to discuss the optimal management of patients with clival chordomas and provide an up-to-date review of the field.

METHODS

A schematic description of the anatomy of the clivus and its surrounding structures is provided based on the modular classification of the surgical corridors used in endoscopic skull base surgery. Postoperative radiotherapy (RT) techniques are described.

RESULTS

The optimal treatment is gross total resection. Recent advances in endoscopic endonasal skull base surgery have allowed very high rates of macroscopic and radiographic complete tumor resection in spite of the challenging location of these lesions. When the tumor location or extension is too lateral or inferior to be effectively resected with an endoscopic approach, an open approach or a combination of endoscopic and open approaches in stages should be considered. Postoperative RT is usually indicated because the likelihood of recurrence is high in spite of complete surgical resection. The main site of recurrence is local and late recurrences are relatively common. The probability of cure is approximately 50% at 10 years and significantly increases when complete tumor resection has been achieved.

CONCLUSION

The preferred treatment for patients with clival chordoma is gross total resection (via endoscopic endonasal surgery when possible) followed by postoperative RT. Treatment at experienced multidisciplinary cranial base centers is key to minimize complications and to enhance the probability of total removal of the tumors.

Skull base chordoma presenting as nasopharyngeal mass with lymph node metastasis

Spheno-occipital chordomas can rarely present as nasopharyngeal mass. Metastases occur only in advanced disease. They can pose a diagnostic dilemma when information about diagnosis of the primary tumor is not available. We present cytological findings in upper cervical lymph node of a case of nasopharyngeal chordoma and discuss possible differential in such a location.

A comparison of cell-cycle markers in skull base and sacral chordomas

OBJECTIVE

Despite refinement of surgical techniques and adjuvant radiotherapy, the prognosis for patients with a chordoma remains poor. Identification of prognostic factors related to tumor biology might improve this assessment and result in molecular markers for targeted therapy. Limited studies have been performed to unravel the impact of cell-cycle markers in chordoma, and those performed have shown inconclusive results. In the current study, we aimed to discover the impact of cyclin-dependent kinase 4 (CDK4) expression and its relation to prognosis and other cell-cycle markers in chordoma.

METHODS

Twenty-five human formalin-fixed, paraffin-embedded chordoma specimens were examined by immunohistochemistry for the expression of CDK4, protein 53 (p53), and murine double minute 2 (MDM2). The MIB-1 labeling index and mitotic index were used for the examination of proliferation. We collected detailed demographic and clinical data.

RESULTS

Overexpression of CDK4, p53, and MDM2 was found in five (20%), seven (28%), and 14 (56%) of the cases, respectively. All three cell-cycle markers showed a significant correlation with MIB1 labeling index. Expression of CDK4 (P = 0.02) and p53 (P < 0.01) were both significantly correlated with poor overall survival. Also, histologically observed necrosis (P < 0.05) and a dedifferentiated tumor subtype (P < 0.01) were related to adverse patient outcome.

CONCLUSION

Our results show that the expression of CDK4 and p53 are related to cell proliferation capacity and worse outcome in patients with chordoma.

Skull base chordomas: clinical features, prognostic factors, and therapeutics

Chordomas of the skull base are one of the rarest intracranial malignancies that arise from ectopic remnants of embryonal notochod. The proximity of many chordomas to neurovascular structures makes gross total resection difficult, and the tendency for recurrence leads to the routine use of adjuvant postoperative radiation. Several surgical approaches are used ranging from extensive craniotomies to minimally invasive endonasal endoscopic approaches. In this review, the histopathology and epidemiology, imaging characteristics, surgical approaches, adjuvant therapies, prognostic factors, and molecular biology of chordomas are described.

Chordoma: current concepts, management, and future directions

Chordoma is a rare bone cancer that is aggressive, locally invasive, and has a poor prognosis. Chordomas are thought to arise from transformed remnants of notochord and have a predilection for the axial skeleton, with the most common sites being the sacrum, skull base, and spine. The gold standard treatment for chordomas of the mobile spine and sacrum is en-bloc excision with wide margins and postoperative external-beam radiation therapy. Treatment of clival chordomas is unique from other locations with an enhanced emphasis on preservation of neurological function, typified by a general paradigm of maximally safe cytoreductive surgery and advanced radiation delivery techniques. In this Review, we highlight current standards in diagnosis, clinical management, and molecular characterisation of chordomas, and discuss current research.

Chordomas of the skull base and cervical spine: clinical outcomes associated with a multimodal surgical resection combined with proton-beam radiation in 40 patients

Previous studies of chordoma have focused on either surgery, radiotherapy, or particular tumor locations. This paper reviewed the outcomes of surgery and proton radiotherapy with various tumor locations. Between 2001 and 2008, 40 patients with chordomas of the skull base and cervical spine had surgery at our hospital. Most patients received proton therapy. Their clinical course was reviewed. Age, sex, tumor location, timing of surgery, extent of resection, and chondroid appearance were evaluated in regard to the progression-free survival (PFS) and overall survival (OS). The primary surgery (PS) group was analyzed independently. The extensive resection rate was 42.5%. Permanent neurological morbidity was seen in 3.8%. Radiotherapy was performed in 75% and the mean dose was 68.9 cobalt gray equivalents. The median follow-up was 56.5 months. The 5-year PFS and OS rates were 70% and 83.4%, respectively. Metastasis was seen in 12.5%. The tumor location at the cranio-cervical junction (CCJ) was associated with a lower PFS (P = 0.007). In the PS group, a younger age and the CCJ location were related to a lower PFS (P = 0.008 and P < 0.001, respectively). The CCJ location was also related to a lower OS (P = 0.043) and it was more common in young patients (P = 0.002). Among the survivors, the median of the last Karnofsky Performance Scale score was 80 with 25.7% of patients experiencing an increase and 11.4% experiencing a decrease. Multimodal surgery and proton therapy thus improved the chordoma treatment. The CCJ location and a younger age are risks for disease progression.

A retrospective clinicopathological study of 37 patients with chordoma: a danish national series

Purpose. There are, in general, few published series on chordoma. It is a rare disease and further data are still needed.

Patients/methods. The data of 37 patients with chordoma were retrospectively analyzed. Treatment was surgical excision in 11, radical radiotherapy in 9 and a combination of the two in 16 cases. The male to female ratio was 2.7 : 1. Median age was 59 years (range 1–89 years).

Results. The most common symptoms at diagnosis were pain (98%), neurological disturbances (42%) and incontinence (33%). The tumours were located in the sacro-coccygeal region in 68%, the spheno-occipital region in 16% and the vertebrae in 16% of the patients. Median tumour.size was 7 cm (range 1–30 cm). Local recurrence occurred in 21/36 treated cases and distant metastases developed in eight patients (23%). The median time to recurrence/progression after primary treatment was 2 years (range 1–10 years). The actuarial 5-year rates of overall, progression-free and symptom-free survival were 40%, 31% and 20%, respectively. The corresponding 10-year rates were 26%, 21% and 14%, respectively. At the time of analysis, seven patients were alive, six without evidence of disease. Four of the six patients without active disease were symptom free. A univariate analysis showed that age, sex, tumour size, histopathology, surgical safety margin, treatment modality and radiation dose did not significantly affect overall, progression-free or symptom-free survival. Only turnout site had a prognostic value with turnouts in the spheno-occipital region carrying the worst prognosis.

Discussion. We conclude that effective treatment against chordomas is still lacking and a prospective multi-institutional registration study may provide more information on the optimal work-up and treatment of this rare disease.

A comprehensive analysis of intracranial chordoma and survival: a systematic review

OBJECTIVE

Despite the published information on cranial chordoma, most of the data regarding survival in these patients has come from a single institution. Here, we perform a systematic review of the literature to evaluate across multiple institutions the overall survival after treatment for intracranial chordoma.

MATERIALS AND METHODS

We systematically analysed every study published in English and found a total of over 2000 patients being treated for intracranial chordoma. The overall 5-year and 10-year survivals in these patients were stratified according to the age (<5 years vs. >5 years and  <40 years vs. >40 years), treatment (surgery and radiation vs. surgery alone) and histological findings (chondroid vs. typical). Data were analysed via Pearson chi-square test and student t-test when appropriate.

RESULTS

A total of 560 non-duplicated patients treated for cranial chordoma met inclusion criteria for this systematic analysis. The survival rate among these patients was 63% (299 patients) and 16% (176 patients) for 5-year and 10-year survivals, respectively. There was no difference in overall survival between the two groups when a cut-off age of 40 years was used (<40 years = 50% vs.  >40 years = 51% at 5-year survival; p = 0.1), but when 5 years was used as the cut-off age, then survival was better for patients in the group older than 5 years of age (<5 years = 14% vs.  >5 years = 66%; p = 0.001). There was no difference between 5-year survival in patients with chordoma with histological chondroid features and those with chordoma possessing typical histology (45% vs. 67%; p = 0.06). When patients who only received surgery were compared to those patients who were treated with surgical intervention in combination with adjuvant radiation treatment, no difference in survival rate was found (54% vs. 56% at 5 years; p = 0.8).

CONCLUSION

The results of our systematic study provide data to predict the survival of intracranial chordoma patients across multiple institutions. Our data suggest that patients younger than 5 years of age may be associated with a worse prognosis, and adjuvant radiation therapy and histological type were not associated with the improvement of survival rates.

Intrasellar chondroid chordoma: a case report

Chordomas are tumors derived from cells that are remnants of the notochord, particularly from its proximal and distal extremes, they are mainly midline and represent approximately 1% of all malignant bone tumors and 0.1 to 0.2% of intracranial neoplasms. Chordomas involving the sellar region are rare. Herein, we describe a 57-year-old male patient presenting with a history of retro-orbital headache, progressive loss of vision, and clinical features of hypopituitarism, for over 2 months. During evaluation, the CT scan revealed a large contrast-enhancing intrasellar tumor with a 3.6-cm largest diameter. The patient underwent transsphenoidal partial resection of the tumor, and histological examination was consistent with the diagnosis of chondroid chordoma. Although chordomas are rare, they may be considered to constitute a differential diagnostic of pituitary adenomas, especially if a calcified intrasellar tumor with bone erosion is diagnosed.

Adjuvant radiation therapy and chondroid chordoma subtype are associated with a lower tumor recurrence rate of cranial chordoma

Cranial chordomas are rare tumors that have been difficult to study given their low prevalence. Individual case series with decades of data collection provide some insight into the pathobiology of this tumor and its responses to treatment. This meta-analysis is an attempt to aggregate the sum experiences and present a comprehensive review of their findings. We performed a comprehensive review of studies published in English language literature and found a total of over 2,000 patients treated for cranial chordoma. Patient information was then extracted from each paper and aggregated into a comprehensive database. The tumor recurrences in these patients were then stratified according to age (<21 vs. >21 years), histological findings (chondroid vs. typical) and treatment (surgery and radiation vs. surgery only). Data was analyzed via Pearson chi-square and t-test. A total of 464 non-duplicated patients from 121 articles treated for cranial chordoma met the inclusion criteria. The recurrence rate among all patients was 68% (314 patients) with an average disease-free interval of 45 months (median, 23 months). The mean follow-up time was 39 months (median, 27 months). The patients in younger group, patients with chordoma with chondroid histologic type, and patients who received surgery and adjuvant radiotherapy had significantly lower recurrence rate than their respective counterparts. The results of our systematic analysis provide useful data for practitioners in objectively summarizing the tumor recurrence in patients with cranial chordomas. Our data suggests that younger patients with chondroid type cranial chordoma treated with both surgery and radiation may have improved rates of tumor recurrence in the treatment of these tumors.

A systematic review of intracranial chondrosarcoma and survival

Most data regarding survival in patients with chondrosarcoma are limited to case studies and small series performed at single institutions. A systematic review was performed to study the relationship between potential prognostic factors and survival. The survival rates were analyzed according to modality of treatment, treatment history, histological subtype, and histological grade. A total of 560 patients with intracranial chondrosarcoma were analyzed. Median follow-up time was 60 months. The 5-year mortality among all patients was 11.5% with median survival of 24 months. Mortality at 5 years was significantly greater for patients with tumors of higher grade, or of the mesenchymal subtype, or who had received surgical resection alone. The results of our systematic review provide useful data in predicting survival among intracranial chondrosarcoma patients.

Brachyury, SOX-9, and podoplanin, new markers in the skull base chordoma vs chondrosarcoma differential: a tissue microarray-based comparative analysis

The distinction between chondrosarcoma and chordoma of the skull base/head and neck is prognostically important; however, both have sufficient morphologic overlap to make delineation difficult. As a result of gene expression studies, additional candidate markers have been proposed to help in separating those entities. We sought to evaluate the performance of new markers: brachyury, SOX-9, and podoplanin alongside the more traditional markers glial fibrillary acid protein, carcinoembryonic antigen, CD24, and epithelial membrane antigen. Paraffin blocks from 103 skull base/head and neck chondroid tumors from 70 patients were retrieved (1969-2007). Diagnoses were made based on morphology and/or whole-section immunohistochemistry for cytokeratin and S100 protein yielding 79 chordomas (comprising 45 chondroid chordomas and 34 conventional chordomas), and 24 chondrosarcomas. A tissue microarray containing 0.6 mm cores of each tumor in triplicate was constructed using a manual array (MTA-1; Beecher Instruments). For visualization of staining, the ImmPRESS detection system (Vector Laboratories) with 2-diaminobenzidine substrate was used. Sensitivities and specificities were calculated for each marker. Core loss from the microarray ranged from 25 to 29% yielding 66-78 viable cases per stain. The classic marker, cytokeratin, still has the best performance characteristics. When combined with brachyury, accuracy improves slightly (sensitivity and specificity for detection of chordoma 98 and 100%, respectively). Positivity for both epithelial membrane antigen and AE1/AE3 had a sensitivity of 90% and a specificity of 100% for detecting chordoma in this study. SOX-9 is apparently common to both notochordal and cartilaginous differentiation, and is not useful in the chordoma-chondrosarcoma differential diagnosis. Glial fibrillary acid protein, carcinoembryonic antigen, CD24, and epithelial membrane antigen did not outperform other markers, and are less useful in the diagnosis of chordoma vs chondrosarcoma. Podoplanin still remains the only positive marker for chondrosarcoma, though its accuracy is less than previously reported.

Tumor-biology and current treatment of skull-base chordomas

Chordomas are rare, slow growing tumors of the axial skeleton, which derive from the remnants of the fetal notochord. They can be encountered anywhere along the axial skeleton, most commonly in the sacral area, skull base and less commonly in the spine. Chordomas have a benign histopathology but exhibit malignant clinical behavior with invasive, destructive and metastatic potential. Genetic and molecular pathology studies on oncogenesis of chordomas are very limited and there is little known on mechanisms governing the disease. Chordomas most commonly present with headaches and diplopia and can be readily diagnosed by current neuroradiological methods. There are 3 pathological subtypes of chordomas: classic, chondroid and dedifferentiated chordomas. Differential diagnosis from chondrosarcomas by radiology or pathology may at times be difficult. Skull base chordomas are very challenging to treat. Clinically there are at least two subsets of chordoma patients with distinct behaviors: some with a benign course and another group with an aggressive and rapidly progressive disease. There is no standard treatment for chordomas. Surgical resection and high dose radiation treatment are the mainstays of current treatment. Nevertheless, a significant percentage of skull base chordomas recur despite treatment. The outcome is dictated primarily by the intrinsic biology of the tumor and treatment seems only to have a secondary impact. To date we only have a limited understanding this biology; however better understanding is likely to improve treatment outcome. Hereby we present a review of the current knowledge and experience on the tumor biology, diagnosis and treatment of chordomas.

Evaluation of 1p36 markers and clinical outcome in a skull base chordoma study

Chordomas are rare embryogenetic tumors, arising from remnants of the notochord, characterized by local invasiveness and variable tendency for recurrence. No molecular markers are currently used in a clinical setting to distinguish chordomas with an indolent or an aggressive pattern. Among the genetic lesions observed in this tumor, one of the most commonly detected is 1p loss. In a previous study we observed 1p36 loss of heterozygosity (LOH) in 85% of the analyzed chordomas. We studied a group of 16 homogeneously treated skull base chordomas (SBCs), reporting 1p36 LOH in 75% of them and determining the expression pattern of eight apoptotic genes mapped at 1p36. No tumors shared a common expression profile with nucleus pulposus, which is considered the only adult normal tissue deriving from notochord. In particular, tumor necrosis factor receptor superfamily genes TNFRSF8, TNFRSF9, and TNFRSF14 were differently expressed compared with control in a higher percentage of tumors (40%-53%) than were the remaining analyzed genes, suggesting that the deregulation of these three genes might have a role in chordoma tumorigenesis. The presence/absence of LOH and the expression/nonexpression of each apoptotic gene were studied in a survival analysis. Our results suggest that the lack of 1p36 LOH or the presence of TNFRSF8 expression might be associated with a better prognosis in patients with SBCs.

Chordomas of the skull base: surgical management and outcome

OBJECT

The goal of this study was to report on the surgical management of skull base chordomas and to evaluate both the short- and long-term treatment outcomes.

METHODS

The authors retrospectively studied data from 49 patients who had undergone consecutive surgeries at a single institution. They also analyzed patterns of chordoma extension. Complications and surgery-related morbidity were recorded. A Kaplan-Meier analysis was performed to determine survival rates in patients 5 and 10 years after their first surgery. Operative approaches were selected on the basis of the predominant tumor extension.

RESULTS

The approach used most frequently was the transethmoidal in 36.3%, followed by the pterional in 23.4% and the retrosigmoid in 23.4%. The tumor was totally removed in 49.4% and subtotally in 50.6%. The rate of total removal was highest at initial surgery (78%) and progressively declined thereafter. In 11.8% of cases a new neurological deficit developed, while the preoperative deficit remained unchanged. In 20% of cases the preoperative deficits improved, but new deficits also appeared. The 5- and 10-year survival rates are 65 and 39%, respectively.

CONCLUSIONS

With an individually tailored surgical approach, total tumor removal in 78% of the cases was achieved at the initial surgery. Radical surgery appears to increase slightly the surgical morbidity, but at the same time prolongs the recurrence-free interval. Chordomas cannot be regarded as surgically curable tumors given the 5- and 10-year survival rates in patients harboring such lesions.

Synovial sarcoma of the sellar region

Primary sarcomas of the sellar region are uncommon, although a wide variety have been reported. To date, no cases of primary synovial sarcoma have been described as occurring at this site. We report an immunohistochemically and molecular genetically confirmed primary synovial sarcoma involving the sellar/parasellar region and cavernous sinus in an adult male. Subtotal resection and radiosurgery proved to be efficacious. The spectrum of primary sellar region sarcomas is summarized.

Skull base chordoma mimicking a preauricular neoplasm in a child: clinicopathological features and biological behaviour

INTRODUCTION

The extreme rarity of chordomas in childhood, the slow growing nature of these tumours and the diverse symptoms may cause many diagnostic problems.

PATIENT

A 9-year-old girl presented with an unusual manifestation of a skull base chordoma. The clinical and pathological features were analysed.

RESULT

In the present case, the initial symptoms of the skull base tumour were completely misleading. The otodynia, the masticatory difficulties and the mass in the preauricular region were not characteristic of skull base chordomas. The female sex, the young age, the large tumour size and the atypical histological pattern of the tumour all indicated a very poor prognosis.

CONCLUSION

The rarity of this tumour in childhood and the atypical lateral and intracranial spread resulted in a serious delay of the diagnosis and in a fatal outcome.

D2-40 functions as an effective chondroid marker distinguishing true chondroid tumors from chordoma

Chordomas and low-grade chondrosarcomas of the central nervous system share many histological features, generating, at times, considerable diagnostic difficulty and, not infrequently, requiring immunohistochemical analysis for appropriate classification. While both chordomas and chondrosarcomas stain positively for S100, only chordomas typically express epithelial antigens like cytokeratins and epithelial membrane antigen. Positive or negative staining with these latter two markers currently represents the only immunohistochemical technique that effectively distinguishes chordomas from chondrosarcomas. A marker that is reliably positive in chondrosarcomas and negative in chordomas has, to date, not been reported. D2-40 is a monoclonal antibody initially developed against M2A, a fetal testis-related antigen now known as podoplanin (aggrus), which has been found to stain a diverse collection of both benign and malignant tissues. In this study, we systematically investigated D2-40 immunoreactivity in a series of 22 chordomas, 20 chondrosarcomas, and 12 enchondromas, in conjunction with cytokeratin and S100 immunostaining. We found that D2-40 robustly and reliably immunostains low-grade chondroid neoplasms (100% of enchondromas and 94% of grades I and II chondrosarcomas), but not chordomas. By contrast, we observed generally strong and diffuse cytokeratin positivity in all cases of chordoma, but not in cases of enchondroma or low-grade chondrosarcoma. Thus, we show that D2-40 behaves as a chondroid marker differentiating true chondroid neoplasms from chordoma. We also demonstrate D2-40 immunoreactivity in two cases of chordoid meningioma and, in doing so, tentatively provide a means to distinguish this tumor from chordoma.

Diagnosing an extra-axial chordoma of the proximal tibia with the help of brachyury, a molecule required for notochordal differentiation

Chordomas are rare malignant bone tumours considered to arise from notochordal remnants that persist in the axial skeleton. Although their morphology can resemble that of a carcinoma, chondrosarcoma or malignant melanoma, the axial location and their well-defined immunophenotype, including expression of cytokeratins (CK7/20/8/18/19) and S100, generally allow the diagnosis to be made with confidence once the possibility is considered. In contrast, making a robust diagnosis of an extra-axial chordoma has been difficult in the absence of specific markers for chordomas. We have recently shown in gene expression microarray and immunohistochemistry studies that brachyury, a transcription factor crucial for notochordal development, is a specific and sensitive maker for chordomas. We now present a case of an intracortical tibial tumour, with detailed report of the imaging, and morphological features consistent with a chordoma, where notochordal differentiation was demonstrated with an antibody to brachyury. The tumour cells were also positive for cytokeratins, including CK19, and S100, CEA, EMA and HMBE1, findings which support the diagnosis of chordoma. Brachyury can be employed as a marker of notochordal differentiation and help identify confidently, for the first time, extra-axial bone and soft tissue chordomas, and tumours which may show focal notochordal differentiation.