Chondrosarcoma: with updates on molecular genetics

Surgical management of chondrosarcomas of the skull-base and temporal bone

OBJECTIVES

To analyze the overall long-term outcome of surgically treated skull base and temporal bone chondrosarcomas.

METHODS

The medical records of patients with surgically treated skull base and temporal bone chondrosarcomas between 1983 and 2024 were thoroughly evaluated.

RESULTS

Out of a total of over 5000 skull base surgeries performed at our center, only 29 patients had histopathologically confirmed chondrosarcomas of the skull base and temporal bone. The mean of patients age was 45.6, and the male-to-female ratio was 1.9:1. The most common symptoms included hearing loss (58.6%), tinnitus (41.4%), diplopia (31%), dysphonia (24.1%), dysphagia (20.7%), vertigo (10.3%), and dizziness (10.3%). The most frequent locations of lesions among the 29 patients are as follows: petroclival region (34.5%), jugular foramen (27.6%), petrous apex (17.2%), middle ear (13.8%), others (3.4%). TO, IFTA, IFTB, IFTC, POTS, and combined surgical approaches were commonly used. The rate of gross total removal and recurrence was 82.6% and 13.8% respectively. The follow-up duration of 6 patients was more than five years and less than ten years whereas ten patients had more than ten years of follow-up.

CONCLUSIONS

Chondrosarcoma of the skull base and temporal bone is a very rare pathology. Due to its multiple potential sites of origin and histological specificity, it presents us with significant challenges. Gross total removal is the primary treatment for chondrosarcoma of the skull base and temporal bone. Personalized decision-making should be considered based on the following aspects: tumor, patient, and surgeon's factors. Postoperative radiation therapy is complementary to surgical treatment in grades II and III lesions to achieve long-term survival.

Presentation, treatment, and outcomes of chondrosarcoma in young adult patients less than age 50: A case series of ten patients

ABSTRACT

Chondrosarcoma is an aggressive bone tumor typically affecting older adults in the 6th and 7th decade. These tumors often present as painful masses in the pelvis, ribs, and long bones and have certain characteristic features on the imaging leading to the diagnosis. The occurrence of these tumors in the young adult population is a rare condition that is not well described. Often, they may be confused with benign counterparts, enchondroma or osteochondroma, which does not require any treatment and are very common. The aim of this case series was to analyze the patient presentation and radiographic image findings as well as surgical treatment and outcomes of ten young adults with chondrosarcoma over a three-year period. Overall, imaging of these tumors in young adults did not necessarily demonstrate all typical features of chondrosarcomas such as endosteal scalloping, calcifications, lobular growth, and high uptake on whole-body bone scans. One patient in the case series passed away from complications from dedifferentiated chondrosarcoma, and nine patients have recovered with no local recurrence.

Rare Dedifferentiated Periosteal Chondrosarcoma with 11-Year Metastatic Relapse: A Case Report

A 50-year-old man presented for evaluation of a periscapular mass. Biopsy suggested a low-grade chondrosarcoma; however, the resected specimen revealed a grade 2 chondrosarcoma with a low-grade dedifferentiated mesenchymal component. The mass multiply recurred as chondrosarcoma without a dedifferentiated component before the patient developed lung metastases of chondrosarcoma without a dedifferentiated component 11 years after the initial diagnosis and died of disease. This is one of the first reported cases of a dedifferentiated chondrosarcoma with low-grade dedifferentiated component. While overall prognosis may be better than in typical dedifferentiated chondrosarcoma, this tumor demonstrated numerous local recurrences as well as metastasis.

Skull Base Tumors

OBJECTIVE

This article reviews the presenting features, molecular characteristics, diagnosis, and management of selected skull base tumors, including meningiomas, vestibular schwannomas, pituitary neuroendocrine tumors, craniopharyngiomas, chordomas, ecchordosis physaliphora, chondrosarcomas, esthesioneuroblastomas, and paragangliomas.

LATEST DEVELOPMENTS

Skull base tumors pose a management challenge given their complex location and, as a result, the tumors and treatment can result in significant morbidity. In most cases, surgery, radiation therapy, or both yield high rates of disease control, but the use of these therapies may be limited by the surgical accessibility of these tumors and their proximity to critical structures. The World Health Organization classification of pituitary neuroendocrine tumors was updated in 2022. Scientific advances have led to an enhanced understanding of the genetic drivers of many types of skull base tumors and have revealed several potentially targetable genetic alterations. This information is being leveraged in the design of ongoing clinical trials, with the hope of rendering these challenging tumors treatable through less invasive and morbid measures.

ESSENTIAL POINTS

Tumors involving the skull base are heterogeneous and may arise from bony structures, cranial nerves, the meninges, the sinonasal tract, the pituitary gland, or embryonic tissues. Treatment often requires a multidisciplinary approach, with participation from radiation oncologists, medical oncologists, neuro-oncologists, and surgical specialists, including neurosurgeons, otolaryngologists, and head and neck surgeons. Treatment has largely centered around surgical resection, when feasible, and the use of first-line or salvage radiation therapy, with chemotherapy, targeted therapy, or both considered in selected settings. Our growing understanding of the molecular drivers of these diseases may facilitate future expansion of pharmacologic options to treat skull base tumors.

A multicenter retrospective analysis of clinical outcomes of intracranial chondrosarcoma in 26 patients

Intracranial chondrosarcoma is a rare tumor with limited reports. We reviewed the clinical outcomes, imaging findings, and pathological characteristics at three centers to improve the diagnosis and treatment of intracranial chondrosarcoma. We retrospectively analyzed 26 patients with intracranial chondrosarcoma who had undergone surgical treatment at Tangdu Hospital of Air Force Military Medical University, Mianyang Central Hospital, and Nanchong Central Hospital from January 2010 to July 2022. Clinical manifestations, imaging features, surgical treatment, prognosis, and overall survival (OS) were analyzed. All 26 chondrosarcomas were located at the skull base. Gross total resection (GTR), subtotal resection (STR), and partial resection (PR) were performed in 14, 10, and 2 cases, respectively. Four cases underwent endoscopic transnasal surgery, while the remaining cases underwent craniotomy. The clinical symptoms were evaluated 1 week after surgery, and 15 cases were relieved to varying degrees. Postoperative complications included pulmonary infection, subcutaneous hydrops, dysphagia and choking, facial numbness, abducens paralysis, and intracranial infection (ICI). Fifteen cases received postoperative adjuvant radiotherapy. Seven cases showed recurrence: two with PR, four with STR, and one with GTR. Six cases received reoperation or radiotherapy after tumor progression, and one untreated patient died 5 months after tumor recurrence. The extent of tumor resection (HR 21.74, 95% CI 1.25-376.6, P = 0.03) and pathological grading (HR 131.99, 95% CI 4.05-4300.5, P = 0.006) were associated with improved OS. We presented our experience in the treatment of intracranial chondrosarcoma at three centers in the past 12 years. Intracranial chondrosarcoma lacked typical imaging features and are difficult to differentiate from other skull base lesions. Maximum extent of tumor resection with minimal injury to neurological function remains the most important treatment strategy. The extent of surgical resection and pathological grading were found to be predictors for OS.

Extremely Rare Case of Extra Skeletal Soft Tissue Chondroma of Masseteric Space: a Diagnostic Challengel

Benign soft tissue chondroma is a rare type of extraskeletal chondrocytic tumour. It usually can be found in skeletal system in extremities. Head and neck region is one of the most uncommon sites for extraskeletal chondroma .Most common site is tongue and there has been paucity of cases arising from the other subsites .We present a case of 56 years gentleman who came to our OPD with a right masticator space swelling. It was nonmalignant on FNAC. He underwent wide local excision through a transparotid approach. Final biopsy & IHC report showed presence of benign chondrocytic neoplasm- soft tissue chondroma (extraskeletal). No further therapy was used and he has been in follow up since then. To our knowledge ,this is the third reported case of masseteric space chondroma.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03705-5.

Dedifferentiated Chondrosarcoma from Molecular Pathology to Current Treatment and Clinical Trials

Dedifferentiated chondrosarcoma (DDCS) is a rare subtype of chondrosarcoma, a primary cartilaginous malignant neoplasm. It accounts for up to 1-2% of all chondrosarcomas and is generally associated with one of the poorest prognoses among all chondrosarcomas with the highest risk of metastasis. The 5-year survival rates range from 7% to 24%. DDCS may develop at any age, but the average presentation age is over 50. The most common locations are the femur, pelvis humerus, scapula, rib, and tibia. The standard treatment for localised disease is surgical resection. Most patients are diagnosed in unresectable and advanced stages, and chemotherapy for localised and metastatic dedifferentiated DDCS follows protocols used for osteosarcoma.

Classification of Chondrosarcoma: From Characteristic to Challenging Imaging Findings

Chondrosarcomas can be classified into various forms according to the presence or absence of a precursor lesion, location, and histological subtype. The new 2020 World Health Organization (WHO) Classification of Tumors of Soft Tissue and Bone classifies chondrogenic bone tumors as benign, intermediate (locally aggressive), or malignant, and separates atypical cartilaginous tumors (ACTs) and chondrosarcoma grade 1 (CS1) as intermediate and malignant tumors. respectively. Furthermore, the classification categorizes chondrosarcomas (including ACT) into eight subtypes: central conventional (grade 1 vs. 2–3), secondary peripheral (grade 1 vs. 2–3), periosteal, dedifferentiated, mesenchymal, and clear cell chondrosarcoma. Most chondrosarcomas are the low-grade, primary central conventional type. The rarer subtypes include clear cell, mesenchymal, and dedifferentiated chondrosarcomas. Comprehensive analysis of the characteristic imaging findings can help differentiate various forms of chondrosarcomas. However, distinguishing low-grade chondrosarcomas from enchondromas or high-grade chondrosarcomas is radiologically and histopathologically challenging, even for experienced radiologists and pathologists.

Chondrosarcoma of the maxilla in a young female: A case report

ABSTRACT

Sarcomas of the head and neck region are rare tumors, constituting less than 1% of malignant neoplasms in this area. Approximately 20% of these sarcomas originate from bone or cartilage. Chondrosarcomas are malignant mesenchymal tumors showing cartilaginous differentiation. These tumors usually show a predilection to the male gender and occur commonly in the older age group. Here, we report a case of chondrosarcoma of the anterior maxilla in a young female.

Patient, Disease, and Treatment-Related Factors Affecting Progression-Free and Disease-Specific Survival in Recurrent Chondrosarcomas of the Skull Base

BACKGROUND

Recurrent skull base chondrosarcomas (CSA) are difficult to treat, and limited data are available to help guide subsequent therapy.

OBJECTIVE

To further characterize the natural history of CSA and identify treatment modalities that were most effective in prolonging progression-free (PFS) and disease-specific survival (DSS).

METHODS

We conducted a single-institution retrospective review of patients with recurrent skull base CSA from 1993 to 2021. Kaplan-Meier survival analyses for PFS and DSS were completed. Univariable and multivariable Cox proportional hazards regression models were used to identify patient-related, treatment-related, and disease-related factors that predicted PFS and DSS.

RESULTS

A total of 28 patients and 84 episodes of recurrence were included. One-year PFS was 70.6%, 5-year PFS was 28.9%, and 10-year DSS was 78.5%. The median time to first progression was 23.9 months (range, 2.8-282 months). In univariable Cox proportional hazards regression, male sex, higher grade histology, fourth or greater progression episode status, distal pattern of recurrence, and treatment of recurrence without surgery or with chemotherapy alone predicted worse PFS. Multivariable regression predicted shortened DSS in male patients (hazard ratio [HR] 0.16; P = .021) and higher-grade tumors (HR 0.22; P = .039). Treatment of recurrence with surgery was associated with, but did not significantly predict, improved DSS (HR 1.78; P = .11).

CONCLUSION

Several patient and disease-specific factors were associated with shorter PFS and DSS in recurrent skull base chondrosarcoma. For recurrences amenable to resection, surgery is recommended for treatment of recurrent CSA. Local recurrence management without surgery results in shorter PFS and DSS.

Benign cartilaginous tumors of the hand, a five-year retrospective study

Benign and malignant cartilaginous bone tumors of the hand are rare findings, however representing a particular pathology due to the capacity to induce significant functional impairment. Even though a large proportion of tumors of the hand and wrist are benign, these may present destructive characteristics, deforming adjacent structures until compromising function. The most appropriate surgical approach for most benign tumors is intralesional lesion resection. Malignant tumors often require wide excision, up to segment amputation to obtain tumor control. A five-year retrospective study was performed on patients admitted in our Clinic with benign cartilaginous tumors of the hand, in which 15 patients were admitted within this period, 10 presenting with enchondroma, four presenting with osteochondroma, and lastly one with chondromatosis. After clinical and imaging evaluation, all the aforementioned tumors were surgically removed. Definitive diagnosis for all bone tumors, either benign or malignant, was established by tissue biopsy and histopathological examination, dictating therapeutic strategy.

Therapeutic Targets and Emerging Treatments in Advanced Chondrosarcoma

Due to resistance to standard anticancer agents, it is difficult to control the disease progression in patients with metastatic or unresectable chondrosarcoma. Novel therapeutic approaches, such as molecule-targeting drugs and immunotherapy, are required to improve clinical outcomes in patients with advanced chondrosarcoma. Recent studies have suggested several promising biomarkers and therapeutic targets for chondrosarcoma, including IDH1/2 and COL2A1. Several molecule-targeting agents and immunotherapies have shown favorable antitumor activity in clinical studies in patients with advanced chondrosarcomas. This review summarizes recent basic studies on biomarkers and molecular targets and recent clinical studies on the treatment of chondrosarcomas.

Identification of medicinal compounds as potential inhibitors for mutated isocitrate dehydrogenases against chondrosarcoma

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Virtual screening of 5000 novel medicinal compounds procured two compounds (5-galloylquinic acid and artocarpetin) capable of establishing interaction with both mutated IDH1 and IDH2 proteins implicated in chondrosarcoma.

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Cell lining prediction studies revealed that both 5-galloylquinic acid and artocarpetin sensitizes chondrosarcoma cell lines and has good cytotoxic influence on CHSA8926 and CHSA0011 cells.

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These compounds possess high acute toxicity values to incite adverse reaction and organ damage in rodents.

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ITGAV, CAPRIN-1, CCL5 COG5 and TNFRSF10B gene are successfully downregulated that are involved in the metastasis inflammation and chondrogenesis by these compounds.

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TP53 expression enhancer, free radical scavenger, MAP kinase stimulant, MM9 expression inhibitor and chemo preventive agent were some biological properties predicted by Prediction of Activity Spectra for substances (PASS) database.

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Artocarpetin had good ADME and druglikness properties as compared to 5-galloylquinic acid, as this compound had low bioavailability score and one lipinski violation for druglikness.

Chondrosarcoma is the third most common cartilaginous bone tumour that is insusceptible to radio- and chemotherapy and it is inclined to metastasis. These resistant qualities are facilitated by mutant variants of isocitrate dehydrogenases (IDH) 1–2 enzyme. These mutant enzymes promote oncogenesis of chondrocytes by changing their epigenetic wardrobe leading to tumour formation. Presently, there are lack of drugs available to be exploited as a remedy for this disease. On the other hand, majority of chemotherapeutic drugs induce cytotoxicity in the cancer cells at the cost of harming surrounding healthy cells, jeopardizing human life. The current study is focused on screening various medicinal compounds against IDH1 and IDH2 combined with insilico gene expression, cancer cells cytotoxicity and ADMET (absorption, distribution, metabolism, excretion and toxicity) studies to elucidate the molecular mechanism against chondrosarcoma and also to uncover pharmacokinetic profile of these compounds. Screening of 5000+ compounds filtered two efficacious compounds (Artocarpetin and 5-Galloylquinic acid) capable of establishing hydrogen bond connections with both IDH variants. Other studies showed that these compounds downregulate ITGAV, CARPIN1, CCL5 and COG5 and TNFRSF10B gene that reduces chondrogenesis and inflammation, Artocarpetin and 5-galloylquinic acid are TP53 expression enhancer and inhibit MM9 expression that promote immunomodulation and apoptosis in these cancers. These compounds are both active against CHSA8926 and CHSA011 cell line of chondrosarcoma. However, the ADME profile of 5-galloylquinic acid is slightly unsatisfactory based on druglikness and bioavailability score criteria as compared to artocarpetin. Both of these compounds are class-5 chemicals and require high doses to elicit adverse response. Our results suggest that artocarpetin and 5-galloylquinic acid are efficacious drug candidates and could be further exploited to validate these findings in vitro.

Dedifferentiated chondrosarcoma: current standards of care

Dedifferentiated chondrosarcomas are aggressive variants of chondrosarcoma, associated with poor outcomes. Tumor biphasism is the norm. The majority of these tumors are symptomatic at presentation. Radiologically, large soft tissue masses with bony destruction predominate. Treatment protocols of these tumors are not well defined. Surgical resection forms the standard of care for localized disease. (Neo)adjuvant therapies remain controversial as the results from multiple (mainly retrospective) studies remain conflicting. Age at presentation, stage and ability to obtain negative resection margins are important prognostic factors. The overall prognosis is dismal. Newer and novel therapies targeting the complex genetic makeup of these tumors have renewed interest in the adjuvant setting that could hold promise in the near future.

Gene expression profiling utilizing extremely sensitive CDNA arrays and enrichment-based network study of major bone cancer genes

Background:

The gene interaction network is a set of genes interconnected by functional interactions among the genes. The gene interaction networks are studied to determine pathways and regulatory mechanisms in model organisms. In this research, the enrichment study of bone cancer-causing genes is undertaken to identify several hub genes associated to the development of bone cancer.

Materials and Methods:

Data on bone cancer is obtained from mutated gene samples; highly mutated genes are selected for the enrichment analysis. Due to certain interactions with each other the interaction network model for the hub genes is developed and simulations are produced to determine the levels of expression. For the array analyses, a total of 100 tumor specimens are collected. Cell cultures are prepared, RNA is extracted, cDNA arrays probes are generated, and the expressions analysis of Hub genes is determined.

Results:

Out of cDNA array findings, only 7 genes: CDKN2A, AKT1, NRAS, PIK3CA, RB1, BRAF, and TP53 are differentially expressed and shown as significant in the development of bone tumors, approximately 15 pathways have been identified, including pathways for non-small cell lung cancer, prostate cancer, pancreatic cancer, chronic myeloid leukemia, and glioma, consisting of all the identified 7 genes. After clinical validations of tumor samples, the IDH1 and TP53 gene revealed significant number of mutations similar to other genes. Specimens analysis showed that RB1, P53, and NRAS are amplified in brain tumor, while BRAF, CDKN2A, and AKT1 are amplified in sarcoma. Maximum deletion mutations of the PIK3CA gene are observed in leukemia. CDKN2A gene amplifications have been observed in virtually all tumor specimens.

Conclusion:

This study points to a recognizable evidence of novel superimposed pathways mechanisms strongly linked to cancer.

Mandibular Chondrosarcoma Reconstructed Using Custom Implant and Radial Forearm Free Flap

ABSTRACT

We describe the case of a 40-year-old male presenting with an enlarging left facial and temporal chondrosarcoma centered on the left mandibular coronoid process resulting in pathologic fractures of the zygomatic arch and focal erosion of the temporal bone. The patient underwent surgical resection via a combined hemicoronal and parotidectomy approach. The zygomatic arch was reconstructed with a patient-specific polyetheretherketone implant, and temporal contour was restored with a buried de-epithelialized radial forearm free flap. Final pathology demonstrated conventional central chondrosarcoma. This case demonstrates an unusual presentation of a rare head and neck chondrosarcoma that originated from the mandibular coronoid process with the unique use of a custom polyetheretherketone implant and vascularized fat and fascial reconstruction.

Chondrosarcoma-from Molecular Pathology to Novel Therapies

Chondrosarcoma (CHS) is the second most common primary malignant bone sarcoma. Overall survival and prognosis of this tumor are various and often extreme, depending on histological grade and tumor subtype. CHS treatment is difficult, and surgery remains still the gold standard due to the resistance of this tumor to other therapeutic options. Considering the role of differentiation of CHS subtypes and the need to develop new treatment strategies, in this review, we introduced a multidisciplinary characterization of CHS from its pathology to therapies. We described the morphology of each subtype with the role of immunohistochemical markers in diagnostics of CHS. We also summarized the most frequently mutated genes and genome regions with altered pathways involved in the pathology of this tumor. Subsequently, we discussed imaging methods and the role of currently used therapies, including surgery and the limitations of chemo and radiotherapy. Finally, in this review, we presented novel targeted therapies, including those at ongoing clinical trials, which can be a potential future target in designing new therapeutics for patients with CHS.

Conventional grade 1 chondrosarcoma: a challenging diagnosis with important implications on therapy and prognosis

Chondrosarcoma (CHS) is a malignant tumor of soft tissue with cartilaginous differentiation that represent one tenth of all malignant proliferations developed from bone tissues. Even if CHS represents the third malignancy with bone localization, after myeloma and osteosarcoma, it is far less diagnosed in the head and neck region. The current paper presented two cases of conventional CHSs, which were diagnosed in Department of Thoracic Surgery and Department of Otorhinolaryngology of Emergency City Hospital, Timişoara, Romania, between February and June 2021. The malignant cases were of peripheral CHSs, one of scapula, and the other one had an extremely rare tracheal location with microscopic features of conventional low-grade tumors (grade 1). In all cases, conservative surgical curative treatment was performed, with a favorable postoperative evolution.

Biological Heterogeneity of Chondrosarcoma: From (Epi) Genetics through Stemness and Deregulated Signaling to Immunophenotype

Chondrosarcoma (ChS) is a primary malignant bone tumor. Due to its heterogeneity in clinical outcomes and resistance to chemo- and radiotherapies, there is a need to develop new potential therapies and molecular targets of drugs. Many genes and pathways are involved in in ChS progression. The most frequently mutated genes are isocitrate dehydrogenase ½ (IDH1/2), collagen type II alpha 1 chain (COL2A1), and TP53. Besides the point mutations in ChS, chromosomal aberrations, such as 12q13 (MDM2) amplification, the loss of 9p21 (CDKN21/p16/INK4A and INK4A-p14ARF), and several gene fusions, commonly occurring in sarcomas, have been found. ChS involves the hypermethylation of histone H3 and the decreased methylation of some transcription factors. In ChS progression, changes in the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K-AKT-mTOR) and hedgehog pathways are known to play a role in tumor growth and chondrocyte proliferation. Due to recent discoveries regarding the potential of immunotherapy in many cancers, in this review we summarize the current state of knowledge concerning cellular markers of ChS and tumor-associated immune cells. This review compares the latest discoveries in ChS biology from gene alterations to specific cellular markers, including advanced molecular pathways and tumor microenvironment, which can help in discovering new potential checkpoints in inhibitory therapy.

Calcifying Pseudoneoplasm of the Neuraxis Involving the Posterior Skull Base: A Case Report and Literature Review

Calcifying pseudoneoplasm of the neuraxis is an uncommon, nonneoplastic fibro-osseous lesion of the central nervous system. At the time of this report, at least 150 cases have been reported in the literature. Because of the rarity of this lesion, it is often diagnostically challenging for radiologists and pathologists alike. In this article, we present a case of a 44-year-old woman with a 5.8-cm intracranial/skull base calcifying pseudoneoplasm of the neuraxis that was concerning for osteosarcoma on initial frozen section. Permanent sections revealed bone and fibrous stroma, calcifications, and nests of histiocytes with granuloma formation. Scattered, focally dense inflammatory foci and spindled cells outlining abundant large nodules of chondromyxoid matrix were also present. In this case report, we also reviewed recent literature for clinical presentations, radiologic findings, and histologic differential diagnoses. Familiarity with this lesion is important to avoid misdiagnosis leading to unnecessary and potentially harmful treatment.

A review of imaging of surface sarcomas of bone

Surface lesions of bone are uncommon. Although their imaging features generally mirror those of their intramedullary counterparts, surface lesions may demonstrate distinct characteristics which along with their unusual location present a diagnostic challenge. Surface sarcomas are usually of a lower grade compared with intramedullary variants, leading to differences in management. Osteosarcoma arising from the cortical surface of the bone is termed juxtacortical or surface osteosarcoma and includes three distinct entities: parosteal, periosteal, and high-grade surface osteosarcoma. We also review the features intracortical osteosarcoma, which some authors include under the umbrella term surface osteosarcoma. These lesions exhibit biologic features distinct from those of conventional intramedullary osteosarcoma, which underlines the importance of accurate imaging diagnosis. Periosteal chondrosarcoma and periosteal Ewing sarcoma also have distinctive imaging appearances. The purpose of this article is to review surface sarcomas of bone with regard to their clinical and radiological features and to discuss the differential diagnosis for each condition.

A system-level approach identifies HIF-2α as a critical regulator of chondrosarcoma progression

Chondrosarcomas, malignant cartilaginous neoplasms, are capable of transitioning to highly aggressive, metastatic, and treatment-refractory states, resulting in significant patient mortality. Here, we aim to uncover the transcriptional program directing such tumor progression in chondrosarcomas. We conduct weighted correlation network analysis to extract a characteristic gene module underlying chondrosarcoma malignancy. Hypoxia-inducible factor-2α (HIF-2α, encoded by EPAS1) is identified as an upstream regulator that governs the malignancy gene module. HIF-2α is upregulated in high-grade chondrosarcoma biopsies and EPAS1 gene amplification is associated with poor prognosis in chondrosarcoma patients. Using tumor xenograft mouse models, we demonstrate that HIF-2α confers chondrosarcomas the capacities required for tumor growth, local invasion, and metastasis. Meanwhile, pharmacological inhibition of HIF-2α, in conjunction with the chemotherapy agents, synergistically enhances chondrosarcoma cell apoptosis and abolishes malignant signatures of chondrosarcoma in mice. We expect that our insights into the pathogenesis of chondrosarcoma will provide guidelines for the development of molecular targeted therapeutics for chondrosarcoma.

Chondrosarcomas are frequently aggressive, understanding the transcriptional changes associated with progression may help in developing new treatments. Here, the authors show that HIF-2α is increased in expression on progression and pharmacological inhibition of the protein together with chemotherapy is a useful strategy for controlling tumour growth in mice.

Bone Tumors Occurring in the Soft Tissues: A Review of the Clinical, Imaging, and Histopathologic Findings

Although rare in everyday practice, malignancies that classically arise from bone or cartilage have been reported to arise de novo in various soft tissues in the body, resulting in a diagnostic challenge for the clinician, radiologist, and pathologist. Differential diagnoses of bone tumors often depend on anatomic location of the lesion. For example, the classic location of osteosarcoma is in the metaphysis of long bones about the knee. Histologically osteosarcoma is characterized by tumor cells that directly produce osteoid, bone, or cartilaginous matrix. In extraskeletal osteosarcoma, the clinical and radiologic picture is very different from a conventional osteosarcoma. They occur in older patients, present as a soft tissue mass often coincidentally following trauma and have a worse prognosis. The imaging characteristics are often nonspecific with mineralized elements in a well-defined soft tissue mass. The mineralized elements may or may not be visible. Magnetic Resonance sequences demonstrate a well circumscribed soft tissue mass with hemorrhagic and enhancing solid components. The pathologic features of extraskeletal osteosarcoma on a microscopic scale are identical to that of skeletal lesions. Likewise, conventional chondrosarcomas present in older patients with a growing, painful soft tissue prominence most commonly involving the long tubular bones. In extraskeletal chondrosarcoma however, the presentation is in somewhat younger patients with a painful soft tissue prominence typically in the head (meninges), neck, or upper leg. The pathologic features are most often that of a myxoid chondrosarcoma which is characterized by strands of small cells over a myxoid matrix. Imaging features include chondroid matrix, heterogenous contrast enhancement, and amorphous internal calcification on Computed Tomography. On Magnetic Resonance sequences the matrix has a low signal on all sequences, and variable inhomogeneity depending on grade of the lesion. Other extraskeletal bone tumors include Ewing's sarcoma and osteoid osteoma amongst other lesions. Although these malignancies may be rare clinical entities, they often exhibit characteristic clinical, imaging, and histopathological findings although differing in treatment and prognosis. Knowledge of these and other common mimicking lesions will help guide the clinician and radiologist to make an accurate diagnosis.

Chondral tumours: discrepancy rate between needle biopsy and surgical histology

OBJECTIVE

To determine the reliability of image-guided core needle biopsy (IGCNB) for the diagnosis and grading of chondral tumours of bone compared with surgical histology.

MATERIALS AND METHODS

Retrospective review of patients with a chondral tumour of bone who underwent IGCNB and surgical resection between January 2007 and December 2017. Data collected included age, sex, skeletal location, technique used for IGCNB, IGCNB result including histological grade and comparison with surgical histology.

RESULTS

A total of 237 patients were included (135 males and 102 females with mean age 53.7 years, range 9-89 years). A total of 174 IGCNBs were CT-guided, 57 ultrasound-guided and 6 fluoroscopic-guided. Two hundred thirty-six of 237 (99.6%) IGCNBs were diagnostic for a chondral tumour, although grade could not be determined in 13 (5.5%) due to necrosis. A positive correlation for tumour grade between IGCNB and surgical histology was achieved in 181 cases (76.4%). In 36 patients (15.2%), IGCNB under-graded the tumour, while in 6 (2.5%), IGCNB over-graded the tumour. Discrepancy between IGCNB and surgical histology was significantly greater for surface/peripheral lesions (p = 0.02) and lesions arising from the flat bones or spine (p = 0.002).

DISCUSSION

IGCNB can achieve a diagnosis of a chondral tumour in a high proportion of cases when compared with final diagnosis from surgical resection specimens. However, correlation of tumour grade between IGCNB and resection histology is less reliable with discordance seen in almost one-quarter of cases, most commonly at non-appendicular sites. Therefore, IGCNB results should not be considered in isolation of imaging and clinical features when planning surgical management.

Diagnostic Challenges in Chondroblastic Maxillary Osteosarcoma: A Case Report

The diagnosis of craniofacial osteosarcoma can be quite challenging, and the condition often goes unrecognized for a considerable period of time. In this report, we discuss the case of a 21-year old woman who presented with a one-year history of a small swelling over the left maxillary alveolar ridge. Upon further investigation, the histopathological examination showed high-grade chondroblastic osteosarcoma. The option of four cycles of neoadjuvant chemotherapy regimen preoperatively was chosen, and left inferior maxillectomy was performed along with reconstruction with obturator prosthesis. This case highlights the difficulties encountered in such rare cases of craniofacial osteosarcomas both in terms of the delay in the establishment of the diagnosis as well as management protocol. A high index of suspicion is required in cases of craniofacial osteosarcoma and early surgical resection with adequate safety margins is warranted.

Exosomes in Bone Sarcomas: Key Players in Metastasis

Bone sarcomas are rare cancers which often present with metastatic disease and are still associated with poor survival rates. Studies in the last decade have identified that exosomes, a type of extracellular vesicle released by cells, play an important role in tumour progression and dissemination. Through the transfer of their cargo (RNAs, proteins, and lipids) across cells, they are involved in cellular cross-talk and can induce changes in cellular behaviour. Exosomes have been shown to be important in metastasis organotropism, induction of angiogenesis and vascular permeability, the education of cells towards a pro-metastatic phenotype or the interaction between stromal and tumour cells. Due to the importance exosomes have in disease progression and the high incidence of metastasis in bone sarcomas, recent studies have evaluated the implications of these extracellular vesicles in bone sarcomas. In this review, we discuss the studies that evaluate the role of exosomes in osteosarcoma, Ewing sarcoma, and preliminary data on chondrosarcoma.

Site-Specific Considerations in the Surgical Management of Skull Base Chondrosarcomas

BACKGROUND

Numerous approaches have been reported in the management of skull base chondrosarcomas. Data are lacking for surgical outcomes by the tumor site of origin.

OBJECTIVE

To provide insight into outcomes by site of origin and factors affecting resection in order to aid in surgical approach selection.

METHODS

A retrospective review was conducted of 49 patients with chondrosarcoma treated at our institution. Charts were reviewed for tumor- and treatment-related factors. Extent of resection was the primary outcome, while neurological function and surgical complications were secondary outcomes. Statistical analyses were performed assessing variables for their impact on the primary outcome.

RESULTS

The gross total resection rate for the overall cohort was 67.3%, and 97.8% of patients were either neurologically stable or improved postoperatively. A petroclival site of origin had lower rates of resection vs all other sites (P < .05). Histology and previous surgery did not predict outcome (P > .05), while previous radiotherapy and cavernous sinus invasion correlated with a subtotal resection (P < .05). In the petroclival cohort, clival, jugular tubercle, and soft tissue involvement correlated with a subtotal resection (P < .05). An endoscopic endonasal transpterygoid approach alone or combined with a transcranial approach yielded the highest resection rates for petroclival tumors (P < .05).

CONCLUSION

Chondrosarcomas pose unique challenges based on the site of origin and pattern of extension. While current surgical strategies appear to yield adequate results at a majority of skull base sites, petroclival tumors represent a particular cohort in which improvement is needed. Based on our analysis, strategies incorporating both endoscopic and transcranial skull base approaches are likely necessary to achieve optimal outcomes.

Extraskeletal chondrosarcoma in the abdominal cavity of a cow

A 25-month-old female crossbred cow presented with astasia, emaciation, and stunted growth. Macroscopic examination revealed a large mass in the abdominal cavity, approximately 100 × 30 × 30 cm. Microscopic examination revealed that the mass consisted of multilobular mature and immature cartilaginous matrices with chondrocytic cells, surrounded by spindle to pleomorphic mesenchymal tumor cells. The cartilaginous matrices consisted of hyaline and elastic cartilages, as confirmed with Azan stain, and Victoria Blue and Van Gieson stain. Immunohistochemistry revealed that the chondrocytic and mesenchymal cells both expressed S-100. The tumor was diagnosed as an extraskeletal chondrosarcoma in the abdominal cavity of this cow.

Malignant Transformation of Recurrent Synovial Chondromatosis: A Case Report and Review

Chondrosarcoma is the second most common primary malignant bone tumor. While the majority arrive de novo, a minority arise from malignant transformation of benign neoplasms, such as osteochondromas. Rarely, chondrosarcomas have been found to originate from other preexisting lesions, such as synovial chondromatosis. A 44-year-old male with a history of a spinal osteochondroma presented with one year of left hip pain and decreased range of motion. On examination, he had a palpable, irregular fullness in the left groin that was minimally tender to palpation. Radiographs and CT of the hip showed extensive soft tissue calcifications and erosion of the femoral neck. The lesion was debulked surgically and histologically diagnosed as synovial osteochondromatosis with no evidence of atypia or cellularity. One year later, his residual disease progressed and resulted in increasingly limited range of motion. He underwent left total hip arthroplasty with simultaneous debulking and the lesion was once again diagnosed as synovial osteochondromatosis. Two months postoperatively, the patient developed a new focus of calcification around the hip joint that was thought to be recurrent disease. Six months later, due to worsening symptoms, he underwent a repeat CT scan. This scan demonstrated extensive intra-articular disease extending into the iliopsoas bursa and around total hip arthroplasty, as well as a new soft tissue nodule with foci of calcification in the left gluteus maximus. The new lesion was debulked surgically and diagnosed as a grade 1 chondrosarcoma. Chondrosarcoma arising from synovial chondromatosis is a rare presentation of the second most common primary malignant bone tumor. It typically presents as an indolent, slowly growing painful mass of large joints in middle aged men. Conventional radiography shows punctate opacities, while MRI and CT reveal diffuse soft tissue calcification and cortical erosion. Low-grade chondrosarcomas are treated with intralesional curettage and adjuvant therapy, while higher grade chondrosarcomas are treated with wide, en bloc excision. Malignant transformation should be considered in any patient presenting with worsening symptoms and a history of a benign bony lesion.

Chondrosarcoma of the dorsal spine - A rare case

Chondrosarcomas of the spine are rare tumors and represent <10% of all chondrosarcomas. In the spine, they may arise from vertebral bodies or posterior elements. They may occur in patients ranging from 13 to 78 years of age. Here, we present a case of a 25-year-old female who presented with complaints of lower backache, stiffness in both lower limbs, and tingling sensation in the right lower limb. On examination, both power and sensations were decreased below waist. Magnetic resonance imaging spine revealed an extradural lesion at D5 vertebral body level with severe cord compression. We received the mass in multiple fragments which were grayish-white and firm to hard in consistency. Microscopically, a chondroid tumor was seen with cells arranged in lobules in abundant myxoid matrix. The neoplastic chondrocytes were large in size and had bizarre hyperchromatic nuclei. Few binucleate and multinucleate forms were also seen along with occasional atypical mitoses. There was permeation and destruction of the host bone, and the tumor was seen invading the marrow spaces. Few foci showed high cellularity. No osteoid formation was seen by the tumor. The tumor was diagnosed as Chondrosarcoma - Grade II.

TP53 in bone and soft tissue sarcomas

Genomic and functional study of existing and emerging sarcoma targets, such as fusion proteins, chromosomal aberrations, reduced tumor suppressor activity, and oncogenic drivers, is broadening our understanding of sarcomagenesis. Among these mechanisms, the tumor suppressor p53 (TP53) plays significant roles in the suppression of bone and soft tissue sarcoma progression. Although mutations in TP53 were thought to be relatively low in sarcomas, modern techniques including whole-genome sequencing have recently illuminated unappreciated alterations in TP53 in osteosarcoma. In addition, oncogenic gain-of-function activities of missense mutant p53 (mutp53) have been reported in sarcomas. Moreover, new targeting strategies for TP53 have been discovered: restoration of wild-type p53 (wtp53) activity through inhibition of TP53 negative regulators, reactivation of the wtp53 activity from mutp53, depletion of mutp53, and targeting of vulnerabilities in cells with TP53 deletions or mutations. These discoveries enable development of novel therapeutic strategies for therapy-resistant sarcomas. We have outlined nine bone and soft tissue sarcomas for which TP53 plays a crucial tumor suppressive role. These include osteosarcoma, Ewing sarcoma, chondrosarcoma, rhabdomyosarcoma (RMS), leiomyosarcoma (LMS), synovial sarcoma, liposarcoma (LPS), angiosarcoma, and undifferentiated pleomorphic sarcoma (UPS).

Endoscopic endonasal transpterygoid transnasopharyngeal management of petroclival chondrosarcomas without medial extension

Chondrosarcomas of the skull base are malignant tumors for which surgery is the primary therapeutic option. Gross-total resection has been demonstrated to improve survival in patients with these tumors. Chondrosarcomas arising from the petroclival synchondrosis harbor particularly unique anatomical considerations that have long been a barrier to achieving such a resection. Endoscopic endonasal transpterygoid approaches have been recently used to gain improved access to such lesions; however, these approaches have classically relied on a medial to lateral transclival trajectory, which provides limited exposure for complete resection of lateral disease. In this paper the authors describe an endoscopic endonasal transpterygoid transnasopharyngeal approach that provides comprehensive access to the petroclival region through dissection of the eustachian tube with resection of the cartilaginous torus tubarius. Of note, the authors have previously demonstrated the superior outcomes and validity of this approach relative to other cranial base techniques for petroclival chondrosarcomas. Surgical outcomes in 5 cases of chondrosarcoma without medial extension are detailed. Gross-total resection was achieved in 4 of 5 patients. Postoperative complications included transient palatal numbness in all patients and eustachian tube dysfunction due to the approach. With tympanostomy tube placement, no patient had persistent hearing loss. Overall, this approach appears to be a safe and effective technique for resection of petroclival chondrosarcomas.

Chondrosarcoma in the Petrous Apex: Case Report and Review

Introduction  Surgical treatment of petrous apex chondrosarcoma is challenging due to the location of the tumor. Using an endoscopic technique for tumor resection is favored since it provides a minimally invasive approach. Case Presentation  A 57 years old female was admitted for acute onset of left abducens nerve palsy and occasional headache mainly on the left side of the retro-orbital area with some radiation to the left occiput. Magnetic resonance imaging (MRI) and computed tomography (CT), at the time of admission, were showed lytic lesion on the left petrous apex and left part of the clivus. Results of metastatic workup were negative. The surgical procedure considered was expanded endoscopic endonasal transclival approach to the left of the petrous apex and reconstruction with a pedicled nasoseptal flap with image guidance system. The pathology confirmed chondrosarcoma on myxoid background. The surgical procedure was uncomplicated. The abducens nerve palsy was resolved in few weeks and no new deficits occurred. Postoperative MRI showed complete resection of the tumor. Conclusion  Expanded endoscopic endonasal transclival approach to petrous apex and reconstruction appears to be safe and feasible technique, capable of achieving total removal of identified lesions near the petrous apex. Nonetheless, future studies with a greater number of patients are crucial to confirm and consolidate this initial impression.

Expression of PD-L1/PD-L2 is associated with high proliferation index of Ki-67 but not with TP53 overexpression in chondrosarcoma

Purpose:

Chondrosarcoma is a malignancy affecting cartilage and is chemo- and radio-resistant. Novel immune checkpoint inhibitors may play a role in treatment; however, expression of programmed cell death ligand 1/2 (PD-L1/PD-L2) in chondrosarcoma is unreported.

Methods:

Chondrosarcoma sections were collected and stained immunohistochemically for PD-L1, PD-L2, Ki-67, and TP53. Clinicopathological parameters were collected and analyzed statistically for associations and correlations. PD-L1/PD-L2 positivity was designated using 1% and 5% cutoffs, respectively.

Results:

A total of 59 chondrosarcoma samples excised between 1997 and 2017 were collected. There were 40 samples assessed as PD-L1-positive and 25 samples as PD-L2-positive. In univariate analysis, PD-L1 positivity was significantly associated with younger age ( P = .001), larger tumor ( P = .025), advanced tumor grade ( P < .001), and recurrence ( P < .001). PD-L1 positivity was not associated with gender, location, serum level of lactate dehydrogenase, or serum level of alkaline phosphatase. PD-L2 positivity was solely significantly associated with younger age ( P = .015). The associations were however insignificant in multivariate analysis. PD-L1 expression was significantly correlated with Ki-67 ( P < .001) and TP53 ( P = .02) expressions. PD-L2 expression was not correlated with either Ki-67 or TP53 expression. When grouped as combined expression (both negative vs. either positive), PD-L1/PD-L2 expression was associated with earlier recurrence ( P < .001), and was negatively correlated with expression of Ki-67 ( P < .001) but not with the expression of TP53.

Conclusion:

PD-L1/PD-L2 is positively expressed in chondrosarcoma and is associated with advanced clinical phenotype. PD-L1/PD-L2 expression is also associated with Ki-67 expression. Our results support the application of immune checkpoint blockade in chondrosarcoma.

Mesenchymal Chondrosarcoma: a Review with Emphasis on its Fusion-Driven Biology

Mesenchymal chondrosarcoma is a rare but deadly form of chondrosarcoma that typically affects adolescents and young adults. While curative intent is possible for patients with localized disease, few options exist for patients in the unresectable/metastatic setting. Thus, it is imperative to understand the fusion-driven biology of this rare malignant neoplasm so as to lead to the future development of better therapeutics for this disease. This manuscript will briefly review the clinical and pathologic features of mesenchymal chondrosarcoma followed by an appraisal of existing data linked to the fusions, HEY1-NCOA2 and IRF2BP2-CDX1, and the associated downstream pathways.

TNF-related apoptosis-inducing ligand (TRAIL) for bone sarcoma treatment: Pre-clinical and clinical data

Bone sarcomas are rare, highly malignant mesenchymal tumours that affect teenagers and young adults, as well as older patients. Despite intensive, multimodal therapy, patients with bone sarcomas have poor 5-year survival, close to 50%, with lack of improvement over recent decades. TNF-related apoptosis-inducing ligand (TRAIL), a member of the tumour necrosis factor (TNF) ligand superfamily (TNFLSF), has been found to induce apoptosis in cancer cells while sparing nontransformed cells, and may therefore offer a promising new approach to treatment. We cover the existing preclinical and clinical evidence about the use of TRAIL and other death receptor agonists in bone sarcoma treatment. In vitro studies indicate that TRAIL and other death receptor agonists are generally potent against bone sarcoma cell lines. Ewing's sarcoma cell lines present the highest sensitivity, whereas osteosarcoma and chondrosarcoma cell lines are considered less sensitive. In vivo studies also demonstrate satisfactory results, especially in Ewing's sarcoma xenograft models. However, the few clinical trials in the literature show only low or moderate efficacy of TRAIL in treating bone sarcoma. Potential strategies to overcome the in vivo resistance reported include co-administration with other drugs and the potential to deliver TRAIL on the surface of primed mesenchymal or immune cells and the use of targeted single chain antibodies such as scFv-scTRAIL.

Mesenchymal chondrosarcoma of the orbit: A case report with 5 years of follow-up

Mesenchymal chondrosarcoma is a rare orbital tumor. Several case reports of this rare tumor have been published in the literature but only 6 cases have documented a follow up of 5 years or more. We report a case of 28 year-old female who presented with left orbital mass. Computed Tomography (CT) revealed a lobulated mass in the superior extraconal space with dense intralesional calcification. Patient underwent complete resection of the mass and histopathology was suggestive of mesenchymal chondrosarcoma. He was given adjuvant radiotherapy and there was no recurrence or metastasis at 5 years of follow-up. The case highlights that a complete resection with adjuvant radiotherapy in cases of orbital mesenchymal chondrosarcoma offers excellent prognosis.

Centrosome amplification in chondrosarcomas: A primary cell culture and cryopreserved tumor sample study

The genetics background underlying the aggressiveness of chondrosarcoma (CS) is poorly understood. One possible cause of malignant transformation is chromosomal instability, which involves an error in mitotic segregation due to numerical and/or functional abnormalities of centrosomes. The present study aimed to evaluate centrosome amplification in cryopreserved samples of tumor tissue from patients with CS. An analysis was performed on 3 primary cultures of tumors from patients who underwent surgery between January 2012 and December 2012 at the Department of Orthopedics at the Barretos Cancer Hospital (Barretos, Brazil). Additionally, cryopreserved tumor specimens were analyzed from 10 patients. The data were assessed using immunocytochemistry and immunohistochemistry staining techniques with monoclonal antibody anti-γ-tubulin. A total of 4 samples of CS cultured cells were obtained from 3 patients. A recurrence of a histological grade III tumor was detected in a female patient with Ollier's syndrome. The other 2 cases were grade I and III. The incidence of centrosome amplification in the primary cultures ranged from 15-64% of the cells. Whereas control cultured fibroblasts showed baseline levels of 4% amplified cells. For the cryopreserved specimens, two independent observers analyzed each sample and counted the cells stained with γ-tubulin, verifying the percentage of affected cells to be a mean of 14%, with the number of clusters ranging between 0-6 per slide. In conclusion, centrosome amplification was found to be a consistent biological feature of CS and may underlie chromosomal instability in this tumor.

Classical intracranial chondrosarcoma: A case report

Intracranial chondrosarcoma is a rare malignant cartilage-forming tumor, with only a small number of cases in the posterior cranial fossa reported previously. The present study reports the case of a 40-year-old male patient who was admitted to Tianjin Huanhu Hospital with a progressive headache and dizziness that had lasted for 2 years. Physical and neurological examinations were normal. Radiography of the skull identified an opaque lesion in the left frontal region of the brain. Cranial computed tomography and magnetic resonance imaging revealed a lesion with calcification and homogenous contrast enhancement in the left frontal region. Subsequently, the patient underwent bicoronal craniotomy and gross total resection of the tumor. Pathological examination confirmed the diagnosis of classical intracranial chondrosarcoma. The patient was discharged 10 days after surgery, with no neurological deficit. One month after initial discharge, the patient underwent γ-knife treatment. A follow-up examination 9 months after surgery revealed that the patient was still alive and had returned to work, with no obvious symptoms or evidence of recurrence.

The clinical pathological significance of Thy1 and CD49f expression in chondrosarcomas

OBJECTIVE

This study investigated the protein expression and clinicopathological significance of Thy1 and CD49f in chondrosarcomas.

METHODS

Thy1 and CD49f protein expression in 59 chondrosarcomas and 33 osteochondromas were measured by immunohistochemical staining.

RESULTS

The percentage of positive Thy1 and CD49f expression was significantly higher in patients with chondrosarcoma than in patients with osteochondroma (P<0.01). The percentage of positive Thy1 and CD49f expression was significantly lower in patients with histological grade I, Enneking stage I, AJCC stage I/II stage, non-metastatic and non-invasive chondrosarcoma than in patients with histological grade III, Enneking stage II+III, AJCC stage III/IV, metastatic and invasive chondrosarcoma (P<0.05 or P<0.01). Thy1 expression was positively correlated with CD49f expression in chondrosarcoma. Kaplan-Meier survival analysis showed that histological grade, AJCC stage, Enneking stage, metastasis, invasion, and Thy1 and CD49f expression significantly correlated with shorter mean survival time in chondrosarcoma patients (P<0.05 or P<0.01). Cox multivariate analysis showed that positive Thy1 and CD49f expression was an independent prognostic factor that negatively correlated with overall postoperative survival.

CONCLUSION

Positive Thy1 and CD49f expression is significantly associated with the progression and poor prognosis of chondrosarcoma.

Delayed diagnosis of clear cell chondrosarcoma after total hip replacement. A case report of a rare entity encountered in common surgery

We report the case of a young female patient who received a total hip replacement due to pain in her left hip joint, misdiagnosed as degenerative arthritis. A clear cell chondrosarcoma (CCCS) in the femoral head had initially not been detected. Seven years later, a periprosthetic recurrence of CCCS close to the former femoral osteotomy occurred. Although a sample of the periprosthetic tumour had been taken for histologic analysis, the recurrence of CCCS remained misdiagnosed for almost 2 years until this rare histopathologic morphology was examined in a specialised multidisciplinary tumour centre. Finally, revision surgery with wide tumour resection margins had to be performed requiring the removal of the total hip replacement and its reconstruction using a modular megaimplant (proximal femoral replacement). Relevant facts of the CCCS as a rare entity regarding histology, treatment and differential diagnoses are discussed.

Chondrosarcoma of maxilla

Chondrosarcoma (CHS) is a rare malignant neoplasm of the jaws. Based on the morphologic features alone, a correct diagnosis of CHS may be difficult. Therefore, correlation of radiological and clinicopathological features are mandatory for the diagnosis of CHS. A case of CHS of the maxilla is reported. A brief discussion on the etiopathogenesis, radiologic and histologic presentation of the tumor and the treatment modalities of this unusual tumor is discussed.

Osteoclast inhibition impairs chondrosarcoma growth and bone destruction

Because Chondrosarcoma is resistant to available chemotherapy and radiation regimens, wide resection is the mainstay in treatment, which frequently results in high morbidity and which may not prevent local recurrence. There is a clear need for improved adjuvant treatment of this malignancy. We have observed the presence of osteoclasts in the microenvironment of chondrosarcoma in human pathological specimens. We utilized the Swarm rat chondrosarcoma (SRC) model to test the hypothesis that osteoclasts affect chondrosarcoma pathogenesis. We implanted SRC tumors in tibia of Sprague-Dawley rats and analyzed bone histologically and radiographically for bone destruction and tumor growth. At three weeks, tumors invaded local bone causing cortical disruption and trabecular resorption. Bone destruction was accompanied by increased osteoclast number and resorbed bone surface. Treatment of rats with the zoledronic acid prevented cortical destruction, inhibited trabecular resorption, and resulted in decreased tumor volume in bone. To confirm that inhibition of osteoclasts per se, and not off-target effects of drug, was responsible for the prevention of tumor growth and bone destruction, we implanted SRC into osteopetrotic rat tibia. SRC-induced bone destruction and tumor growth were impaired in osteopetrotic bone compared with control bone. The results from our animal model demonstrate that osteoclasts contribute to chondrosarcoma-mediated bone destruction and tumor growth and may represent a therapeutic target in particular chondrosarcoma patients.

The clinical pathological significance of FRAT1 and ROR2 expression in cartilage tumors

PURPOSE

Chondrosarcoma is a malignant bone tumor with poor prognosis. Surgical treatment is the first choice for chondrosarcomas. Chondrosarcoma is not sensitive to chemotherapy and radiotherapy. Identification of biological markers is important for the early diagnosis and targeted treatment of chondrosarcoma. This study investigated the protein expression and clinicopathological significance of ROR2 and FRAT1 in 59 chondrosarcomas and 33 osteochondromas.

METHODS

ROR2 and FRAT1 protein expression in tissues was measured by immunohistochemistry.

RESULTS

The percentage of positive ROR2 and FRAT1 expression was significantly higher in patients with chondrosarcoma than in patients with osteochondroma (P < 0.01). The percentage of positive ROR2 and FRAT1 expression was significantly lower in patients with histological grade I, AJCC stage I/II stage, Enneking stage I, non-metastatic and invasive chondrosarcoma than patients with histological grade III, AJCC stage III/IV, Enneking stage II + III, metastatic and invasive chondrosarcoma (P < 0.05 or P < 0.01). ROR2 expression was positively correlated with FRAT1 expression in chondrosarcoma. Kaplan-Meier survival analysis demonstrated that histological grade, AJCC stage, Enneking stage, metastasis, invasion, and ROR2 and FRAT1 expression significantly correlated with a short mean survival time of patients with chondrosarcoma (P < 0.05 or P < 0.01). Cox multivariate analysis showed that positive ROR2 and FRAT1 expression was an independent prognostic factor that negatively correlated with postoperative survival and positively correlated with mortality.

CONCLUSION

Positive ROR2 and FRAT1 expression is associated with the progression and poor prognosis of chondrosarcoma.

Does ifosfamide therapy improve survival of patients with dedifferentiated chondrosarcoma?

BACKGROUND

Dedifferentiated chondrosarcoma remains a significant therapeutic challenge. Studies performed to date have not identified efficacious chemotherapy regimens for this disease.

QUESTIONS/PURPOSES

We sought to (1) evaluate the disease-specific survival at 2 and 5 years of patients with dedifferentiated chondrosarcoma; (2) assess the prognostic variables (both patient- and treatment-related), including the use of chemotherapy with ifosfamide, that relate to survivorship; and (3) assess specific toxicities associated with ifosfamide use.

METHODS

Data from 41 patients with dedifferentiated chondrosarcoma diagnosed and treated at the University of Texas MD Anderson Cancer Center from 1986 to 2010 were analyzed for demographics, treatments, oncologic outcomes, and prognostic variables. There were 14 women and 27 men. The mean age at diagnosis was 58 years (range, 26-86 years). Seven patients presented with metastasis. Surgical resection alone was performed in 11 patients; resection and chemotherapy in 26 patients; resection and radiotherapy in two patients; and resection, chemotherapy, and radiotherapy in two patients. Ifosfamide-based regimens were used for 16 patients. In general, ifosfamide was used when the tumor was located in the trunk or if cisplatin was discontinued as a result of toxicity. Minimum followup was 8 months (median, 68 months; range, 8-281 months). Survival was estimated using Kaplan-Meier plots and analyzed by using the Cox proportional hazards model.

RESULTS

Disease-specific survival rates at 2 and 5 years were 33% and 15%, respectively. Multivariate analysis revealed that treatment without ifosfamide-based chemotherapy was the only independent negative prognostic factor for disease-specific survival (hazard ratio, 0.4; 95% confidence interval, 0.17-0.92; p = 0.03). Ifosfamide was discontinued in a patient as a result of renal dysfunction and was decreased in dose in another patient who developed encephalopathy.

CONCLUSIONS

In this small retrospective study, it appeared that ifosfamide-based adjuvant chemotherapy combined with surgical resection offered a treatment advantage compared with patients who did not receive the drug in patients with dedifferentiated chondrosarcoma, although disease-specific survival for patients who have this rare tumor remains dismal.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.