Low-grade Chondrosarcoma Research Articles

Synovial Chondromatosis of the Hand and Wrist: A 35-Year Retrospective Case Review.

Background: Synovial chondromatosis is a condition that rarely occurs in the hand and wrist. Recurrence and malignant transformation are two potential complications of the disease. We set out to retrospectively review 35 years of practice within our sarcoma and tertiary hand unit and identify recurrence or malignant transformation. Methods: This is a retrospective analysis of patients with synovial chondromatosis seen at our sarcoma and tertiary hand unit for the past 35 years. Incidence of recurrence or malignant transformation was noted. Where possible, patients were clinically and radiologically reviewed with range of motion, grip strength and patient evaluation measures obtained. Results: Of 12 patients presenting to the practice, seven patients were followed up and, of these, two demonstrated recurrences. The recurrence was diagnosed based on patient-reported symptoms, clinical examination and the requisition of further imaging. Of the five who could not be followed up, two demonstrated recurrence and one had malignant transformation with a low-grade chondrosarcoma on histology. Conclusions: While a rare disease, we demonstrated recurrence within our small case series. Fusion to obliterate the joint is an option in the management of recurrence. For the diagnostically challenging, genetic testing may be beneficial, though genetic rearrangements are not seen in all cases. All patients should be counselled on symptoms to watch for as a small proportion may experience recurrence and a small percentage may undergo malignant transformation. Level of Evidence: Level IV (Therapeutic).

Two rare localizations of chondrosarcoma: cervical and thoracic spine

Chondrosarcoma is a primary malignant bone tumor, with spinal involvement being rare. Diagnosing this condition can be challenging and typically requires histological verification. Chondrosarcoma has the potential to invade locally and spread systemically. We report the case of 32 year-old women presenting with back pain and weight loss. Magnetic resonance imaging of the spine showed a bone growth at the low cervical spine which extends to the upper dorsal spine. Histological examination showed low-grade chondrosarcoma. Given the tumor proximity to the spinal cord, an incomplete surgical excision was performed followed by radiotherapy sessions. Clinical course was marked by partial regression of the tumor process with a stability of the radiological image of the tumor after a three years follow-up. Our case is original because of the bifocality of the chondrosarcoma in two adjacent segments of the spine.

Preoperative prediction of histopathological grading in patients with chondrosarcoma using MRI-based radiomics with semantic features

BackgroundDistinguishing high-grade from low-grade chondrosarcoma is extremely vital not only for guiding the development of personalized surgical treatment but also for predicting the prognosis of patients. We aimed to establish and validate a magnetic resonance imaging (MRI)-based nomogram for predicting preoperative grading in patients with chondrosarcoma.MethodsApproximately 114 patients (60 and 54 cases with high-grade and low-grade chondrosarcoma, respectively) were recruited for this retrospective study. All patients were treated via surgery and histopathologically proven, and they were randomly divided into training (n = 80) and validation (n = 34) sets at a ratio of 7:3. Next, radiomics features were extracted from two sequences using the least absolute shrinkage and selection operator (LASSO) algorithms. The rad-scores were calculated and then subjected to logistic regression to develop a radiomics model. A nomogram combining independent predictive semantic features with radiomic by using multivariate logistic regression was established. The performance of each model was assessed by the receiver operating characteristic (ROC) curve analysis and the area under the curve, while clinical efficacy was evaluated via decision curve analysis (DCA).ResultsUltimately, six optimal radiomics signatures were extracted from T1-weighted imaging (T1WI) and T2-weighted imaging with fat suppression (T2WI-FS) sequences to develop the radiomics model. Tumour cartilage abundance, which emerged as an independent predictor, was significantly related to chondrosarcoma grading (p < 0.05). The AUC values of the radiomics model were 0.85 (95% CI, 0.76 to 0.95) in the training sets, and the corresponding AUC values in the validation sets were 0.82 (95% CI, 0.65 to 0.98), which were far superior to the clinical model AUC values of 0.68 (95% CI, 0.58 to 0.79) in the training sets and 0.72 (95% CI, 0.57 to 0.87) in the validation sets. The nomogram demonstrated good performance in the preoperative distinction of chondrosarcoma. The DCA analysis revealed that the nomogram model had a markedly higher clinical usefulness in predicting chondrosarcoma grading preoperatively than either the rad-score or clinical model alone.ConclusionThe nomogram based on MRI radiomics combined with optimal independent factors had better performance for the preoperative differentiation between low-grade and high-grade chondrosarcoma and has potential as a noninvasive preoperative tool for personalizing clinical plans.

Case Study: Subclavicular Extraosseous Chondroma

Extraosseous chondroma is a rare soft tissue tumor composed of hyaline cartilage with no connection to bone or periosteum. Chondroid lesions present radiological aspects that are common for benign lesions and conventional low-grade chondrosarcomas. The differentiation is not always possible and should be considered a meticulous clinical and pathologic imaging. It can sometimes be misdiagnosed as a synovial cyst or a more serious condition such as synovial sarcoma. We present the case of a 14-year-old soccer player, presented to the trauma and orthopedic service of the Center of Medical Excellence in Height (CEMA by FIFA) with a history of 4 years ago with a solid abnormality characteristic located in the right subclavicular area. An ultrasound study was requested, which reported a lobulated, hypoechoic subcutaneous nodule, with acoustic reinforcement and without vascularity with Doppler. At radiographic level, normal soft tissue is shown, without nodular lesions. The nodule was surgically removed, then, was sent to histopathology study, which reported: Fibroadipose tissue of the periclavicular region with changes compatible with soft tissue chondroma -extra-skeletal- without lesion on the resection edges. In addition, a literature review was made focused on the search for subclavicular extraosseous chondromas, finding no case in the literature, for which this report was made, due to the strange location of the chondroma.

Study of two Cases of Laryngeal Chondrosarcomas: Presentation, Management, And Outcomes

Laryngeal chondrosarcomas are rare malignant tumors arising in the cartilage of the larynx, posing diagnostic and therapeutic challenges. This study presents two cases treated at Ibn Sina University Hospital in Rabat, Morocco, emphasizing clinical presentations, diagnostic approaches, treatment strategies, and outcomes. Case 1 involved a 56-year-old chronic smoker presenting with inspiratory dyspnea, leading to total laryngectomy. Histopathology confirmed low-grade chondrosarcoma. Case 2 featured a 67-year-old chronic smoker with dysphonia, leading to total laryngectomy with adjuvant radiotherapy for a moderately differentiated chondrosarcoma. Imaging, endoscopy, and histopathology played crucial roles in diagnosis. The discussion outlines the rarity of laryngeal chondrosarcomas, their typical clinical manifestations, and the importance of imaging and histopathology in confirming the diagnosis. Surgical resection remains the mainstay of treatment, with considerations for partial surgery in specific cases. Radiotherapy is limited, while chemotherapy has no curative role. Prognosis correlates with histological grade and the completeness of surgical resection, with a five-year survival rate ranging from 79% to 90%. Recurrences and metastases are infrequent after complete surgery. In conclusion, a multidisciplinary approach involving oncologists, surgeons, and radiotherapists is crucial for tailored management, ensuring optimal outcomes and quality of life for laryngeal chondrosarcoma patients.

An Unusual Presentation of Low-grade Chondrosarcoma of the First Metatarsal Bone requiring extensive Resection: A Case Report

Chondrosarcoma (CS) is one of the common malignant bone tumours arising from chondrocytes with variable degrees of malignancy. It is mainly noted in flat bones like the pelvis and scapula, and sometimes in long bones like the proximal femur. This case report describes a 40-year-old female who presented with pain over her right great toe for six months and swelling for four months. An open biopsy revealed low-grade CS. Subsequently, the patient underwent amputation of the first ray till the tarsometatarsal joint with meticulous dissection of the tumour mass. At eight years of follow-up, the patient had no recurrence and no functional disability. Therefore, in cases of low-grade CS, first ray amputation along with excision of the tumour mass helps avoid recurrence and metastasis, providing a satisfactory functional outcome.

Oncology

The October 2023 Oncology Roundup360 looks at: Are pathological fractures in patients with osteosarcoma associated with worse survival outcomes?; Spotting the difference: how secondary osteosarcoma manifests in retinoblastoma survivors versus conventional cases; Accuracy of MRI scans in predicting intra-articular joint involvement in high-grade sarcomas around the knee; Endoprosthetic reconstruction for lower extremity soft-tissue sarcomas with bone involvement; Local relapse of soft-tissue sarcoma of the extremities or trunk wall operated on with wide margins without radiation therapy; 3D-printed, custom-made prostheses in patients who had resection of tumours of the hand and foot; Long-term follow-up for low-grade chondrosarcoma; Evaluation of local recurrence and diagnostic discordance in chondrosarcoma patients undergoing preoperative biopsy; Radiological scoring and resection grade for intraosseous chondrosarcoma.

Low-Grade Chondrosarcoma Mimicking Chondroid Chordoma: A Case Report

Chondrosarcomas and Chordomas account for the majority of primary skull base tumors, which are slow growing and locally aggressive. These tumors cause severe cranial nerve neuropathies. Both these tumors have similar clinical, radiological, and histological resemblances. Histopathology, along with immunohistochemistry, helps to differentiate these tumors. We are presenting a case of 39year old female who came with double vision, squint, headache, and tingling sensation over the right side of the face. Examination and investigations concluded a skull base tumor near the cavernous sinus. Surgical resection of the lesion was done and sent for histopathology. Microscopy showed hyaline cartilaginous islands, myxoid matrix, and individual cells with vacuolated cytoplasm and ovoid nucleus. Immunohistochemistry showed positive for S100. Final diagnosis of low-grade Chondrosarcoma was made. Keywords: Chondrosarcoma, Skull base tumors, Chordoma, S100

Brachial plexus block for the resection of a chondrosarcoma during COVID-19: A case report

A case report of a 35-year-old female with a large low-grade chondrosarcoma of the left humerus. Resection was performed under regional anaesthesia (interscalene brachial plexus block): this is a useful technique where there are limited resources and during the COVID-19 pandemic.

Oncology

The August 2023 Oncology Roundup360 looks at: Giant cell tumour of bone with secondary aneurysmal bone cyst does not have a higher risk of local recurrence; Is bone marrow aspiration and biopsy helpful in initial staging of extraskeletal Ewing’s sarcoma?; Treatment outcomes of extraskeletal Ewing’s sarcoma; Pathological complete response and clinical outcomes in patients with localized soft-tissue sarcoma treated with neoadjuvant chemoradiotherapy or radiotherapy; Long-term follow-up of patients with low-grade chondrosarcoma in the appendicular skeleton treated by extended curettage and liquid nitrogen; Cancer-specific survival after limb salvage versus amputation in osteosarcoma; Outcome after surgical treatment of dermatofibrosarcoma protuberans: does it require extensive follow-up, and what is an adequate resection margin?; Management of giant cell tumours of the distal radius: a systematic review and meta-analysis.

Is total-body MRI useful as a screening tool to rule out malignant progression in patients with multiple osteochondromas? Results in a single-center cohort of 319 adult patients.

To evaluate the results of total-body (TB) MRI used as a screening tool for assessment or exclusion of malignant transformation in patients with hereditary multiple osteochondromas (HMO). In a single-institute cohort of MO patients, 366 TB-MRI examinations, including T1-weighted and STIR images, were performed for screening and follow-up purposes to rule out the malignant transformation, and retrospectively analyzed. In each patient, the presence and location of osteochondromas in the axial and appendicular bones were recorded. Forty-seven patients underwent a second TB surveillance in this period. STIR sequences were used to identify sites of increased signal intensity that could represent suspicious thickened cartilage caps or indeterminate reactive changes related to osteochondromas. In 82% of patients, one or more OC locations were determined in one or more flat bones. In 366 exams, nine OC (2,5 %) with suspicious imaging features were identified. These proved to be peripheral chondrosarcomas after targeted MRI and resection were performed. All nine malignant lesions were in flat bones (pelvis 5, ribs 3, scapula 1). Three of these patients were 19 years of age. In 12 patients who had peripheral or intraosseous low-grade chondrosarcoma in their history, before their first TB-MRI, no new lesions were identified. Twenty-three additional TB-MRI exams, demonstrating focal high T2 signal intensity, also gave rise to performing additional targeted MRI. One OC of the distal femur was excised and appeared benign. No suspicious cartilage caps were depicted on the remaining 22 targeted MRI exams but instead increased T2 signal was clarified by reactive changes (frictional bursitis, soft tissue edema) in close relation with benign osteochondromas. No malignant lesions were found in 47 patients who had a second TB surveillance (mean interval between exams 3.2 years, range 2-5 years). TB-MRI can identify malignant transformation of osteochondromas in HMO patients. All peripheral chondrosarcomas occurred in flat bones (ribs, scapula, pelvis) in our study. TB-MRI might assist in triage between higher risk patients with a high burden of OC, including the location of OC in main flat bones vs lower risk patients without OC of the flat bones.

Distinguishing enchondroma from low-grade chondrosarcoma using a multi-stage deep learning model for patient radiographs and histopathology.

e23500 Background: Enchondroma and low-grade (grade 1) chondrosarcoma are cartilaginous tumors of the peripheral bone. Enchondroma is benign, requiring only routine clinical monitoring. Chondrosarcoma is malignant, demanding prompt and aggressive treatment to prevent metastasis. Despite drastically different treatment protocols, these tumors are histologically and radiographically similar, making them difficult to tell apart. Even specialized treatment, years of experience, and access to both imaging modalities, pathologists and radiologists have reported low reliability in distinguishing between these two tumors. Better diagnostic and grading strategies are needed for these lesions. In this study, we propose a two-stage computer vision framework for distinguishing enchondroma from low-grade chondrosarcoma using deep learning. Methods: Our team compiled a ground truth dataset of radiographic and histological images from the annotated records of Dr. Henry Jaffe, a pioneering authority in musculoskeletal pathology. From his records, 55 cases of low-grade chondrosarcoma and 19 cases of enchondroma containing both radiology and histology imaging were identified and included. Radiographs and histology samples corresponding to the same individual were paired together to create 290 paired images of enchondroma and 318 paired images of low-grade chondrosarcoma (pair = 1 histology + 1 radiograph). These image pairings were randomly split into training (~80%) or validation (~20%) groups, excepting minimal reallocations to prevent leakage between training and validation data. All images were preprocessed and augmented for improved model training. Image pairings (one histology image, one radiograph) corresponding to the same patient case were passed through separate VGG16 models pre-trained on ImageNet weights. These models produced two feature vectors as outputs, which were concatenated and subsequently passed through a second-stage binary classification network to predict tumor identity. Results: After 17 epochs, the model recorded training loss and accuracy of 0.6723 and 0.7583, and validation loss and accuracy of 0.7362 and 0.7373, respectively – an improvement upon diagnostic accuracies reported in previous studies. Conclusions: We have created a two-stage deep learning model that predicts whether patient radiographs and histology show enchondroma or low-grade chondrosarcoma. The trained model’s validation accuracy of 73.7% improves upon past reported methods. This suggests that computer vision methods that utilize multiple imaging modalities might augment physicians' capability to discriminate between these two tumor types.

A rare case of chondrosarcoma at the posterior costovertebral junction: a case report.

The authors present a case of a 47-year-old female with a complaint of chronic pain in the right posterior upper chest, dyspnea, and episodes of dizziness.The diagnosis of low-grade chondrosarcoma at the posterior costovertebral junction was made by video-assisted thoracic surgery and computed tomography.The surgical management included resection of the tumor and parts of adjacent ribs. Chondrosarcoma is chemotherapy and radiotherapy-resistant. The total surgical excision of the tumor with sufficient margins is usually curative. A follow-up is necessary because of the potential for recurrence.

Curettage or Resection? A Review on the Surgical Treatment of Low-Grade Chondrosarcomas.

Introduction Low-grade chondrosarcomas (LG-CS), including atypical cartilaginous tumors (ACT), are locally aggressive lesions. The focus of the discussion sits on the differential diagnosis between benign lesions or aggressive cartilaginous tumors and on their treatment: intralesional curettage or wide resection. This study presents the results obtained in the surgical treatment of 21 cases of LG-CS. Methods This retrospective study includes 21 consecutive patients from a single center with LG-CS who underwent surgery from 2013 to 2021. Fourteen were located in the appendicular skeleton, and seven in the axial (shoulder blade, spine, or pelvis). Mortality rate, recurrence, metastatic disease, overall survival, recurrence-free survival, and metastatic disease-free survival were analyzed for each type of procedure and each disease location. Operative complications and residual tumors were also recorded in cases where resection was performed. Survival was calculated using the Kaplan-Meier method. Results Thirteen patients underwent intralesional curettage (11 appendicular and 2 axial lesions), and eight underwent wide resection (5 axial and 3 appendicular). There were six recurrences during the follow-up, 43% of the axial lesions recurred, rising to 100% in axial curetted ones. Appendicular LG-CS recurred in 21% of cases, and only 18% of curetted appendicular lesions were not eradicated. The overall survival for the entire follow-up is 90.5%, and the 5-year survival rate is 83% (12 patients have adequate follow-up). Recurrence-free and metastasis-free survival were higher in resection cases, with 75% and 87.5%, vs. curettage 69.2% and 76.9%, respectively. In 9% of cases, the preoperative biopsy was inconsistent with the pathology of the surgical specimen. Discussion LG-CS and ACT are described as having high survival and low potential for metastatic disease. For this reason, these lesions are subject to a change in treatment philosophy to reflect these characteristics. Intra-lesional curettage is advocated as a less invasive technique for eradicating atypical cartilage tumors and has fewer and less severe complications, which was in accordance with our findings. Diagnosis, however, is challenging; misgrading is frequent and should be considered. Because of this risk of under-treating higher-grade lesions, some authors still defend wide-resection as the treatment of choice. We observed a trend towards longer survival, less recurrence, and metastatic disease with wide resection. Metastatic disease was higher than expected, present in 19% of cases, and always associated with local recurrence. Conclusion LG-CS is still a diagnostic and treatment challenge; patient selection is fundamental. Overall survival is high, independent of treatment choice or lesion location. We found a higher rate of metastatic disease than described in the literature; this, coupled with a misgrading rate of 9%, reflects the difficulty of preoperative diagnosis and the risk of treating high-grade chondrosarcomas as a low-grade lesion. More studies should be carried out with larger samples to obtain statistically robust results.

Low-grade chondrosarcoma and atypical cartilaginous tumor

Central atypical cartilaginous tumor (ACT)/chondrosarcoma, grade 1 (CS1) is a locally aggressive chondrogenic tumor, as the 5th WHO Classification of Tumors (2020) listed. These lesions, that need for a resection as management, can resemble to enchondroma that is a fully benign lesion. This last is simply followed on the imaging to avoid the risk of possible complications. We will review the clinical and imaging features that allow to the radiologist to make a differential diagnosis among these lesions in order to choose for each lesion the most appropriate diagnostic/therapeutical management.

Differentiated chondrosarcoma, variants of transformation of the sarcomatous component of the tumor

Introduction. It is generally accepted that dedifferentiated chondrosarcomas are a result of transformation of low-grade (grade I and II) malignant chondrosarcomas into sarcoma with marked signs of cellular and tissue anaplasia with more aggressive clinical progression. Morphological examination of dedifferentiated chondrosarcomas allows to detect presence of pre-existent low-grade malignant chondrosarcoma tissue. Dedifferentiated chondrosarcomas comprise about 10 % of all chondrosarcomas. Most frequently, this tumor is located in the femur, pelvic bones, and humerus. A common clinical complication of dedifferentiated chondrosarcomas is pathological fracture. This disease is characterized by more aggressive progression with unfavorable prognosis compared to conventional types of chondrosarcomas.Aim. To study in detail the data of laboratory, clinical, radiological and morphological examinations of patients with different chondrosarcoma types for refinement of the algorithm of dedifferentiated chondrosarcoma examination and diagnosis.Materials and methods. Between 2008 and 2022, data of 160 patients with chondrosarcomas of varying locations and differentiation were analyzed. Diagnosis of “cartilaginous tumor” was made in all patients after clinical and radiological exams, as well as preoperative biopsy. Diagnosis of “dedifferentiated chondrosarcoma” was made in 30 patients. Radiological exam included several methods (X-ray, X-ray computed tomography, and magnetic resonance imaging) and modes of patient examination. Morphological diagnosis included routine techniques of histological analysis with gentle decalcification and subsequent immunohistochemical (PD-L1, PU-1, CD8, CD20, Ki67, CD34) and genetic analyses (IDH1/IDH2).Results. Among 160 patients, preoperative biopsy verified the diagnosis of “dedifferentiated chondrosarcoma” only in 6 patients. In 4 patients, the possibility of chondrosarcoma transformation into poorly differentiated sarcoma of non-cartilaginous structure was suspected. At the stage of postoperative material examination, diagnosis of “dedifferentiated chondrosarcoma” was confirmed in 4 patients with suspicion of more malignant tumor transformation and newly made in 20 more patients. Female patients were a little more common (19/11). Mean patient age was 59 years. Pathological fracture at the preoperative stage was observed in 6 patients. In almost one third of the cases (36 %), decreased differentiation of chondrosarcoma compared to preoperative biopsy was observed. It is important for management of these patients that in approximately 13 % of chondrosarcoma cases, recurrence with decreased tumor differentiation is observed.Conclusion. Radical surgical resection remains the standard treatment of chondrosarcoma as the effectiveness of radio- and chemotherapy is limited though it remains important in dedifferentiated type of the disease. These circumstances lead to the use of tumor immunotherapy targeted at the search for potential use of the immune response for recognition and killing of various malignant cells including dedifferentiated chondrosarcoma. Consequently, a promising research direction is determination of the significance of tumor-associated macrophages, as well as tumor-infiltrating lymphocytes as antitumor factors and biomarkers affecting clinical and morphological characteristics of oncological diseases.

Suivi à long terme de patients atteints de chondrosarcome de bas grade du squelette appendiculaire traités par curetage prolongé et azote liquide

BackgroundChondrosarcoma is the second most common sarcoma of bone, accounting for about 25% of primary bone tumors. Histological grading is the single most important determinant of local recurrence and metastases, where low-grade chondrosarcoma (grade 1: atypical cartilaginous lesion) is associated with 10 years survival rate 79-100%. There has been always a debate about the need for wide resection in managing low-grade chondrosarcoma, where several reports describe successful management with intralesional curettage and adjuvant therapy, minimizing the need for complex reconstructive procedures and improving the expected outcomes. HypothesisGrade 1 chondrosarcoma of the appendicular skeleton can be successfully treated through extended curettage and liquid nitrogen with favorable oncological and functional outcomes. Patients and methodsWe retrospectively assessed 113 patients with low-grade chondrosarcoma in the appendicular skeleton, who were treated by extended curettage, adjuvant therapy using liquid nitrogen, reconstruction using polymethyl methacrylate and prophylactic fixation. Patients were assessed regarding incidence of recurrence, incidence of non-oncological complications and functional outcome. ResultsThe mean follow up period was 110 months. In three patients (2.7%), local recurrence occurred. Five point three percent of the patients got non-oncological complications that were successfully managed. The mean MSTS score was 95%, with no evidence of distant metastases or disease related mortality. ConclusionGrade 1 chondrosarcoma in the appendicular skeleton can be effectively treated using extended curettage, liquid nitrogen as adjuvant and cement as filler. Prophylactic fixation is required to avoid pathological fractures. When done properly, excellent functional outcome is expected. Level of evidenceIV, case series (retrospective comparative study).

Outcome of surgical interventions for solitary enchondromas of the hand : Controversial issues.

Enchondromas are the most common primary bone tumors of the hand and are benign cartilaginous tumors. This study evaluated the clinical and radiologic results of patients who underwent surgical interventions for isolated hand enchondromas with aminimum follow-up of 1 year and focused on controversial issues. Aretrospective study included 66patients with solitary hand enchondromas with follow-up >12months who underwent surgical interventions between January 2014 and July 2020. Patients with multiple enchondromas, low-grade chondrosarcoma, or who missed follow-up were excluded. All patients underwent thorough curettage with or without filling. Follow-up visits were done at 6 weeks, 3months, 6months, and annually. Demographic characteristics, clinical presentation, surgical details, final histologic examination, rehabilitation program, complications, and recurrences were recorded. The range of movement of the affected hand was compared to the contralateral one. Radiological evaluation of defect filling using the modified Neer classification was done. Of the patients 25were male and 41were female (38right hand affection, 28left hand affection), the mean age was 30.4 ± 11.9years. Indications for surgery were local pain, swelling, and pathological fractures. The mean follow-up period was 28.8 ± 12.9months (range 12-67months). The mean MSTS score was 28.73 ± 1.6 (range 24-30). The middle finger was most frequently affected (18cases, 27.3%) and the proximal phalanx was the most common location (37cases, 56.1%). The mean length of lesions was 18.9 ± 6.67 mm and the mean width was 12.3 ± 4.1 mm. According to the modified Neer classification, 50cases were classified as grade1(healed), 16cases as grade2 (healed with defects), and no case presented as persistent or recurrent lesions. Solitary hand enchondroma can be effectively treated with adequate curettage, with or without autologous bone grafting, with positive functional and radiological outcomes. When compared to grafting from the iliac crest, harvesting bone from the distal radius provides ashorter hospital stay and reduced complication rates.

Comparative analysis of miRNA expression in dedifferentiated and well-differentiated components of dedifferentiated chondrosarcoma

Dedifferentiated chondrosarcoma (DDCS) is a rare malignant cartilage tumor arising out of a low-grade chondrosarcoma, whereby the well-differentiated and the dedifferentiated components coexist in the same localization. DDCS has a massively increased metastatic potential in comparison to low-grade chondrosarcoma. So far, the underlying mechanisms of DDCS development and the increased malignancy are widely unknown. Targeted DNA sequencing revealed no genetic differences between both tissue components. Besides genetic events, alterations in epigenetic control may play a role in DDCS development. In this preliminary study, we have analyzed the differential miRNA expression in paired samples of both components of four primary DDCS cases and a rare lung metastasis with both components using the nCounter MAX analysis system from NanoString technologies. We identified 21 upregulated and two downregulated miRNAs in the dedifferentiated components of the primary cases. Moreover, three miRNAs were also significantly deregulated in the dedifferentiated component of the lung metastasis, supporting their possible role in DDCS development. Additionally, validated targets of the 23 deregulated miRNAs are involved in signaling pathways, like PI3K/Akt, Wnt/β-catenin, and TGF-β, as well as in cellular processes, like cell cycle regulation, apoptosis, and dedifferentiation. Further investigations are necessary to confirm and understand the role of the identified miRNAs in DDCS development.

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.