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The accurate classification of bone tumours is crucial for guiding clinical decisions regarding treatment and follow-up. However, differentiating between various tumour types is challenging due to the rarity of certain entities, high intra-class variability, and limited training data in clinical practice. This study proposes a multimodal deep learning model that integrates clinical metadata and X-ray imaging to improve the classification of primary bone tumours. The dataset comprises 1,785 radiographs from 804 patients collected between 2000 and 2020, including metadata such as age, affected bone site, tumour position, and gender. Ten tumour types were selected, with histopathology or tumour board decisions serving as the reference standard. Methods: Our model is based on the NesT image classification model and a multilayer perceptron with a joint fusion architecture. Descriptive statistics included incidence and percentage ratios for discrete parameters, and mean, standard deviation, median, and interquartile range for continuous parameters. Results: The mean age of the patients was 33.62 ± 18.60 years, with 54.73% being male. Our multimodal deep learning model achieved 69.7% accuracy in classifying primary bone tumours, outperforming the Vision Transformer model by five percentage points. SHAP values indicated that age had the most substantial influence among the considered metadata. Conclusion: The joint fusion approach developed in this study, integrating clinical metadata and imaging data, outperformed state-of-the-art models in classifying primary bone tumours. The use of SHAP values provided insights into the impact of different metadata on the model's performance, highlighting the significant role of age. This approach has potential implications for improving diagnostic accuracy and understanding the influence of clinical factors in tumour classification. [ABSTRACT FROM AUTHOR]

Osteosarcoma is the most common malignant bone cancer in pediatric patients. Patients who respond poorly to chemotherapy experience worse clinical outcomes with a high mortality rate. The major challenge is the lack of effective drugs for these patients. To introduce new drugs for clinical approval, preclinical studies based on in vitro models must demonstrate the potency of the tested drugs, enabling the drugs to enter phase 1 clinical trials. Patient-derived cell culture is a promising testing platform for in vitro studies, as they more accurately recapitulate cancer states and genetic profiles compared to cell lines. In the present study, we established patient-derived osteosarcoma cells (PDC) from a patient who had previously been diagnosed with retinoblastoma. We identified a new variant of a germline mutation in the RB1 gene in the tissue of the patient. The biological effects of this PDC were studied to observe whether the cryopreserved PDC retained a feature of fresh PDC. The cryopreserved PDC preserved the key biological effects, including cell growth, invasive capability, migration, and mineralization, that define the conserved phenotypes compared to fresh PDC. From whole genome sequencing analysis of osteosarcoma tissue and patient-derived cells, we found that cryopreserved PDC was a minor population in the origin tissue and was selectively grown under the culture conditions. The cryopreserved PDC has a high resistance to conventional chemotherapy. This study demonstrated that the established cryopreserved PDC has the aggressive characteristics of osteosarcoma, in particular the chemoresistance phenotype that might be used for further investigation in the chemoresistant mechanism of osteosarcoma. In conclusion, the approach we applied for primary cell culture might be a promising method to generate in vitro models for functional testing of osteosarcoma. [ABSTRACT FROM AUTHOR]

Chordoma is an uncommon and malignant bone tumor that originates from remnants of the embryonic notochord. To date, only nine cases of lower cervical chordomas have been documented globally. This study aims to highlight an extraordinary case involving a 14-year-old female with chordoma affecting the fifth to seventh cervical vertebrae. [ABSTRACT FROM AUTHOR]

Abstract The accurate classification of bone tumours is crucial for guiding clinical decisions regarding treatment and follow-up. However, differentiating between various tumour types is challenging due to the rarity of certain entities, high intra-class variability, and limited training data in clinical practice. This study proposes a multimodal deep learning model that integrates clinical metadata and X-ray imaging to improve the classification of primary bone tumours. The dataset comprises 1,785 radiographs from 804 patients collected between 2000 and 2020, including metadata such as age, affected bone site, tumour position, and gender. Ten tumour types were selected, with histopathology or tumour board decisions serving as the reference standard. Methods Our model is based on the NesT image classification model and a multilayer perceptron with a joint fusion architecture. Descriptive statistics included incidence and percentage ratios for discrete parameters, and mean, standard deviation, median, and interquartile range for continuous parameters. Results The mean age of the patients was 33.62 ± 18.60 years, with 54.73% being male. Our multimodal deep learning model achieved 69.7% accuracy in classifying primary bone tumours, outperforming the Vision Transformer model by five percentage points. SHAP values indicated that age had the most substantial influence among the considered metadata. Conclusion The joint fusion approach developed in this study, integrating clinical metadata and imaging data, outperformed state-of-the-art models in classifying primary bone tumours. The use of SHAP values provided insights into the impact of different metadata on the model’s performance, highlighting the significant role of age. This approach has potential implications for improving diagnostic accuracy and understanding the influence of clinical factors in tumour classification.

The bone is the most common location of breast cancer metastasis. Bone metastasis causes pain and skeletal-related events (SREs), and affects the quality of life and survival of breast cancer patients. Bone-modifying agents, including bisphosphonates and denosumab, reduce the risk of SREs in these patients. Among bisphosphonates, zoledronic acid is preferred due to its higher efficacy. Denosumab is marginally more effective than zoledronic acid in reducing the frequency of SREs. Patients with renal impairment should receive zoledronic acid with caution due to nephrotoxicity, and denosumab is an alternative option in these patients. Osteonecrosis of the jaw is a rare but severe complication of both zoledronic acid and denosumab, and all patients should undergo dental examinations before and during treatment. Although these drugs can reduce the risk of SREs in bone metastasis, no significant improvement in survival has been noted. This study reviews the effects and adverse events of bone-modifying agents for the treatment of bone metastasis from breast cancer.

Chondroblastoma is a rare benign tumor, typically presenting in the first two decades. Systemic metastases in chondroblastoma are extremely rare and it is the rarity of these metastases which lead the World Health Organisation to re-classify this lesion from "intermediate" to "benign" in its updated classification of bone tumors in 2020. We present an unusual case of a 55 year-old male patient who presented with multiple FDG-avid bone lesions on a background of conventional chondroblastoma of the rib excised at another institution 11-years previously. Two of these lesions were also histologically-proven as conventional chondroblastoma at biopsy. This case highlights that, although rare, metastases can be seen in patients with chondroblastoma. To our knowledge, this is the only case with an unusual pattern of metastases limited to bone. [ABSTRACT FROM AUTHOR]

High-grade osteosarcoma, a primary malignant bone tumour, is experiencing a global increase in reported incidence with varied prevalence. Despite advances in management, which include surgery and neoadjuvant chemotherapy often an unsatisfactory outcome is found due to poor or heterogeneous response to chemotherapy. Our study delved into chemotherapy responses in osteosarcoma patients and associated molecular expressions, focusing on CD95 receptor (CD95R), interferon (IFN)-γ, catalase, heat-shock protein (Hsp)70, and vascular endothelial growth factor (VEGF). Employing immunohistochemistry and Huvos grading of post-chemo specimens, we analysed formalin-fixed paraffin-embedded (FFPE) osteosarcoma tissue of resected post-chemotherapy specimens from Dr. Soetomo General Academic Hospital in Surabaya, Indonesia (DSGAH), spanning from 2016 to 2020. Results revealed varied responses (poor 40.38%, moderate 48.08%, good 11.54%) and distinct patterns in CD95R, IFN-γ, catalase, Hsp70, and VEGF expression. Significant differences among response groups were observed in CD95R and IFN-γ expression in tumour-infiltrating lymphocytes. The trend of diminishing CD95R expression from poor to good responses, accompanied by an increase in IFN-γ, implied a reduction in the count of viable osteosarcoma cells with the progression of Huvos grading. Catalase expression in osteosarcoma cells was consistently elevated in the poor response group, while Hsp70 expression was highest. VEGF expression in macrophages was significantly higher in the good response group. In conclusion, this study enhances our understanding of immune-chemotherapy interactions in osteosarcoma and identifies potential biomarkers for targeted interventions. [ABSTRACT FROM AUTHOR]

Abstract Osteosarcoma is the most common malignant bone cancer in pediatric patients. Patients who respond poorly to chemotherapy experience worse clinical outcomes with a high mortality rate. The major challenge is the lack of effective drugs for these patients. To introduce new drugs for clinical approval, preclinical studies based on in vitro models must demonstrate the potency of the tested drugs, enabling the drugs to enter phase 1 clinical trials. Patient-derived cell culture is a promising testing platform for in vitro studies, as they more accurately recapitulate cancer states and genetic profiles compared to cell lines. In the present study, we established patient-derived osteosarcoma cells (PDC) from a patient who had previously been diagnosed with retinoblastoma. We identified a new variant of a germline mutation in the RB1 gene in the tissue of the patient. The biological effects of this PDC were studied to observe whether the cryopreserved PDC retained a feature of fresh PDC. The cryopreserved PDC preserved the key biological effects, including cell growth, invasive capability, migration, and mineralization, that define the conserved phenotypes compared to fresh PDC. From whole genome sequencing analysis of osteosarcoma tissue and patient-derived cells, we found that cryopreserved PDC was a minor population in the origin tissue and was selectively grown under the culture conditions. The cryopreserved PDC has a high resistance to conventional chemotherapy. This study demonstrated that the established cryopreserved PDC has the aggressive characteristics of osteosarcoma, in particular the chemoresistance phenotype that might be used for further investigation in the chemoresistant mechanism of osteosarcoma. In conclusion, the approach we applied for primary cell culture might be a promising method to generate in vitro models for functional testing of osteosarcoma.

Telangiectatic osteosarcoma is a rare variant of osteosarcoma histologically and clinically similar to hemangiosarcoma (HSA). This case series describes the imaging and cytologic features of four histologically confirmed telangiectatic osteosarcomas, including the use of cytochemical stains. Alkaline phosphatase (ALP) was applied to Wright–Giemsa‐stained cytology slides, and Factor VIII immunohistochemistry was evaluated. Cytologic characteristics included atypical mesenchymal cells with evidence of acute and chronic hemorrhage. Telangiectatic osteosarcoma cases had positive ALP cytochemical staining, while control HSA cases were negative. Factor VIII immunohistochemistry was negative in telangiectatic osteosarcoma and positive in HSA. Cytologic diagnosis of telangiectatic osteosarcoma with positive ALP cytochemical staining can help differentiate this neoplasm from HSA. [ABSTRACT FROM AUTHOR]

This technical report illustrates the technique to perform computed tomography (CT)-guided bone biopsies in the body and dens of the axis (C2 vertebra) through a posterior transpedicular approach with the use of preoperative contrast-enhanced scans to highlight the course of the vertebral artery. The technique is presented through two exemplification cases: a pediatric patient with osteoblastoma and secondary aneurysmal bone cyst and one adult patient with melanoma metastasis. This case highlights the potential of the CT-guided posterolateral/transpedicular approach for performing safe and effective biopsies in the body and dens of C2, even in pediatric patients.

This technical report illustrates the technique to perform computed tomography (CT)-guided bone biopsies in the body and dens of the axis (C2 vertebra) through a posterior transpedicular approach with the use of preoperative contrast-enhanced scans to highlight the course of the vertebral artery. The technique is presented through two exemplification cases: a pediatric patient with osteoblastoma and secondary aneurysmal bone cyst and one adult patient with melanoma metastasis. This case highlights the potential of the CT-guided posterolateral/transpedicular approach for performing safe and effective biopsies in the body and dens of C2, even in pediatric patients. [ABSTRACT FROM AUTHOR]

Summary: Background: Atypical cartilaginous tumour (ACT) and high-grade chondrosarcoma (CS) of long bones are respectively managed with active surveillance or curettage and wide resection. Our aim was to determine diagnostic performance of X-rays radiomics-based machine learning for classification of ACT and high-grade CS of long bones. Methods: This retrospective, IRB-approved study included 150 patients with surgically treated and histology-proven lesions at two tertiary bone sarcoma centres. At centre 1, the dataset was split into training (n = 71 ACT, n = 24 high-grade CS) and internal test (n = 19 ACT, n = 6 high-grade CS) cohorts, respectively, based on the date of surgery. At centre 2, the dataset constituted the external test cohort (n = 12 ACT, n = 18 high-grade CS). Manual segmentation was performed on frontal view X-rays, using MRI or CT for preliminary identification of lesion margins. After image pre-processing, radiomic features were extracted. Dimensionality reduction included stability, coefficient of variation, and mutual information analyses. In the training cohort, after class balancing, a machine learning classifier (Support Vector Machine) was automatically tuned using nested 10-fold cross-validation. Then, it was tested on both the test cohorts and compared to two musculoskeletal radiologists' performance using McNemar's test. Findings: Five radiomic features (3 morphology, 2 texture) passed dimensionality reduction. After tuning on the training cohort (AUC = 0.75), the classifier had 80%, 83%, 79% and 80%, 89%, 67% accuracy, sensitivity, and specificity in the internal (temporally independent) and external (geographically independent) test cohorts, respectively, with no difference compared to the radiologists (p ≥ 0.617). Interpretation: X-rays radiomics-based machine learning accurately differentiates between ACT and high-grade CS of long bones. Funding: AIRC Investigator Grant.

ABSTRACT Chondrosarcoma, an unusual malignant neoplasm, develops in cartilaginous tissue and presents low rate of metastasis, mainly affecting the axial skeleton from the adult to senile dogs. In the face of unusual occurrence of chondrosarcoma in the long bones of young dogs, the present report aimed to describe it in the right humerus of a two-and-a-half-year-old Siberian Husky, attended at the Veterinary Hospital of the University of Franca, with limping of the right thoracic limb, for 20 days. The radiographic examination of the humerus showed bone lysis and periosteal proliferation. In the incisional biopsy, proliferation of atypical chondrocytes with diffuse distribution, interspersed with compact bone matrix, was observed. The amputation of the limb was performed, and the fragment histopathological analysis showed grade I chondrosarcoma. Periodic returns were made for neoplastic staging, and at 240 days after surgery lung metastases were detected, however, the tutor did not authorize chemotherapy and radiotherapy for financial reasons and due to the absence of respiratory symptoms so far (410 days after surgery). Although uncommon, chondrosarcoma can affect the long bones of young dogs, with clinical signs similar to other bone neoplasms, and, even with the radical limb amputation, can demonstrate systemic metastasis.

Background: The artery of Adamkiewicz (AKA) is vital for spinal cord blood supply. Its role in embolization procedures for bone metastases can cause serious complications. We explored its prevalence, anatomical variation, and effect on spinal embolization using N-butyl cyanoacrylate (NBCA) in patients with bone metastases. Purpose: To understand the impact and variability of AKA in spinal embolizations in cases of bone metastases to reduce complications and improve patient outcomes. Material and Methods: We examined data from 454 patients who underwent spinal embolization with NBCA between 2009 and 2018. The presence, anastomoses, and tumor features of AKA were assessed via pre-procedure imaging and angiography. Complications were classified per the CIRSE Classification System. Results: AKA was found in 22.8% of patients, predominantly left-sided and originating from T8 to L1. Direct and indirect anastomoses were present in 66.6% and 33.4% of patients, respectively. Extra-compartmental invasion was linked with direct anastomosis (P = 0.004). High-grade complications were rare but included one instance of bilateral lower limb paralysis. Partial embolization was necessary in 22.8% of cases due to AKA. Conclusion: The study underscores the need for rigorous preoperative evaluation of AKA origin and anastomoses in patients undergoing spinal embolization for bone metastases. Given the significant presence of AKA and related anastomoses, especially with renal extra-compartmental tumors, caution is advised to reduce complications and optimize patient outcomes. Further research is required for best practice guidelines involving bone metastases and AKA. [ABSTRACT FROM AUTHOR]

Simple Summary: OFC (Osteitis Fibrosa Cystica) and Brown Tumours, skeletal lesions commonly found in chronic kidney disease (CKD) patients, are influenced by various risk factors, such as age, sex, medications affecting calcium metabolism, and vitamin D deficiency. The primary cause is secondary hyperparathyroidism, leading to imbalances in calcium and phosphorus levels and osteoclast activation. Other factors, like RAAS hyperactivity and chronic inflammation, may also contribute to their development. The recently described involvement of KRAS mutations turned Brown Tumours from reactive lesions to potentially neoplastic lesions. To manage these conditions, pharmacologic treatments like bisphosphonates, calcimimetics, vitamin D supplementation, and denosumab can help by reducing hyperparathyroidism, restoring calcium levels, and preventing OFC occurrence. Brown Tumours, being rare, lack sufficient understanding regarding their manifestation and treatment. However, considering their impact on CKD patients' quality of life, it is crucial for nephrologists and medical practitioners working with dialysis patients to be aware of various diagnostic and treatment options. Osteitis fibrosa cystica (OFC) and Brown Tumours are two related but distinct types of bone lesions that result from the overactivity of osteoclasts and are most often associated with chronic kidney disease (CKD). Despite their potential consequences, these conditions are poorly understood because of their rare prevalence and variability in their clinical manifestation. Canonically, OFC and Brown Tumours are caused by secondary hyperparathyroidism in CKD. Recent literature showed that multiple factors, such as hyperactivation of the renin–angiotensin–aldosterone system and chronic inflammation, may also contribute to the occurrence of these diseases through osteoclast activation. Moreover, hotspot KRAS mutations were identified in these lesions, placing them in the spectrum of RAS–MAPK-driven neoplasms, which were until recently thought to be reactive lesions. Some risk factors contributed to the occurrence of OFC and Brown Tumours, such as age, gender, comorbidities, and certain medications. The diagnosis of OFC and Brown Tumours includes clinical symptoms involving chronic bone pain and laboratory findings of hyperparathyroidism. In radiological imaging, the X-ray and Computed tomography (CT) scan could show lytic or multi-lobular cystic alterations. Histologically, both lesions are characterized by clustered osteoclasts in a fibrotic hemorrhagic background. Based on the latest understanding of the mechanism of OFC, this review elaborates on the manifestation, diagnosis, and available therapies that can be leveraged to prevent the occurrence of OFC and Brown Tumours. [ABSTRACT FROM AUTHOR]

CT-guided bone biopsies are currently the diagnostic tool of choice for histopathological (and microbiological) diagnoses of skeletal lesions. Several research works have well-demonstrated their safety and feasibility in almost all skeletal regions. This comprehensive review article aims at summarizing the general concepts in regard to bone biopsy procedures, current clinical indications, the feasibility and the diagnostic yield in different skeletal sites, particularly in the most delicate and difficult-to-reach ones. The choice of the correct imaging guidance and factors affecting the diagnostic rate, as well as possible complications, will also be discussed. Since the diagnostic yield, technical difficulties, and complications risk of a CT-guided bone biopsy significantly vary depending on the different skeletal sites, subdivided analyses of different anatomical sites are provided. The information included in the current review article may be useful for clinicians assisting patients with possible bone neoplasms, as well as radiologists involved in the imaging diagnoses of skeletal lesions and/or in performing bone biopsies. [ABSTRACT FROM AUTHOR]

Abstract Background Limb salvage reconstruction for pelvic tumors, especially periacetabular tumors, is challenging. We combined the use of dual mobility bearing and 3D-printed hemipelvic prosthesis to improve function and reduce the probability of complications after hemi-pelvic resection in patients with primary acetabular malignancy. The purpose of this study was to evaluate the efficacy and safety of this combination. Methods Between October 2011 and May 2021, 11 patients with malignancies involving the acetabulum received hemipelvic replacement with a 3D-printed prosthesis and dual mobility bearing. Follow‐up of postoperative survival, complications, and Musculoskeletal Tumor Society 93 (MSTS-93) lower limb functional scores were carried out. A finite element model of the postoperative pelvis was developed and input into the finite element analysis software. The Von Mises equivalent stress formula was used to analyze the stress distribution of each part of the pelvis under one gait cycle and the stress distribution at different angles of the hip joint. Results By the last follow-up, 9 of the 11 patients (81.8%) were still alive, and 2 patients had local tumor recurrence. The complications including 1 deep infection and 1 dislocation of the artificial joint. Excluding 1 amputation patient, the average score of the remaining 8 patients at the last follow-up was 21.4/30 (71.3%) on the MSTS-93. In the reconstructed pelvis, stress distributions were concentrated on the junction between hemipelvic prosthesis and screw and iliac bone on the resected side, and between femoral prosthesis stem and femoral bulb, while the stress of polyethylene lining was small. Before impact, the polyethylene lining will rotate at a small angle, about 3°. The inner stress of polyethylene liner is greater than the outer stress in all conditions. The polyethylene liner has no tendency to slide out. Conclusion Pelvic tumor resection and reconstruction using 3D-printed hemipelvic prosthesis combined with dual mobility bearing was an effective treatment for pelvic tumors. Our patients achieved good early postoperative efficacy and functional recovery. The dual mobility bearing is beneficial to prevent dislocation, and the mechanical distribution and wear of the prosthesis are acceptable.

Abstract The phase III clinical study of adjuvant liposomal muramyl tripeptide (MTP-PE) in resected high-grade osteosarcoma (OS) documented positive results that have been translated into regulatory approval, supporting initial promise for innate immune therapies in OS. There remains, however, no new approved treatment such as MTP-PE for either metastatic or recurrent OS. Whilst the addition of different agents, including liposomal MTP-PE, to surgery for metastatic or recurrent high-grade osteosarcoma has tried to improve response rates, a mechanistic hiatus exists in terms of a detailed understanding the therapeutic strategies required in advanced disease. Here we report a Bayesian designed multi-arm, multi-centre, open-label phase II study with randomisation in patients with metastatic and/or recurrent OS, designed to investigate how patients with OS might respond to liposomal MTP-PE, either given alone or in combination with ifosfamide. Despite the trial closing because of poor recruitment within the allocated funding period, with no objective responses in eight patients, we report the design and feasibility outcomes for patients registered into the trial. We demonstrate the feasibility of the Bayesian design, European collaboration, tissue collection with genomic analysis and serum cytokine characterisation. Further mechanistic investigation of liposomal MTP-PE alone and in combination with other agents remains warranted in metastatic OS.

ABSTRACT A two-year old mare was referred to the veterinary hospital because of an increase in the volume of the head on the frontal and left side as well as dyspnoea. Radiographic examination showed an osseous radiopaque spherical mass, with a granular aspect, affecting the left frontal, maxillary, and nasal bones. A frontal sinusotomy was performed, and the frontal sinus was found to be totally obliterated by a granular, yellowish, and hard mass containing multiple spicules. Histologically, it was a multilobulated osseous neoplasia diagnosed as a multilobular osseous tumour. Because of poor prognosis, the animal was euthanized. Necropsy showed that the left nasal cavity was totally effaced as were the nasal sinuses and that the nasal turbinate disappeared because of the hard, yellowish, and granular mass measuring 20 × 14 × 14 cm that surrounded the molar teeth and extended to the cribriform plate. This tumour, which was described only once in horses, is more frequently observed in older dogs’ skulls, and must be considered as a differential diagnosis in horses with sinonasal diseases.

Background: The purpose of this study was to evaluate the implant survival, functional score and complications of intercalary endoprostheses implanted for metastatic involvement of the femoral and humeral diaphysis. Methods: The selected group covered patients with bone metastasis who were surgically treated with an intercalary endoprosthesis between 2012 and 2021. The functional outcome was evaluated with the Musculoskeletal Tumor Society (MSTS) scoring system, and complications were evaluated by using the failure classification for prosthetics designed by Henderson. Results: The mean follow-up was 29.8 months. In our group of 25 patients with 27 intercalary endoprostheses (18 femurs, 9 humeri), there were 7 implant-related complications (25.9%), which were more common on the humerus (4 cases, 44.4%) than on the femur (3 cases, 16.7%). Only type II failure—aseptic loosening (5 cases, 18.5%)—and type III failure—structural failure (2 cases, 7.4%)—occurred. There was a significantly higher risk of aseptic loosening of the endoprosthesis in the humerus compared with that in the femur (odds ratio 13.79, 95% confidence interval 1.22–151.05, p = 0.0297). The overall cumulative implant survival was 92% 1 year after surgery and 72% 5 years after surgery. The average MSTS score was 82%. The MSTS score was significantly lower (p = 0.008) in the humerus (75.9%) than in the femur (84.8%). Conclusions: The resection of bone metastases and replacement with intercalary endoprosthesis has excellent immediate functional results with an acceptable level of complications in prognostically favourable patients.

Intraosseous epidermoid cyst is a rare nonneoplastic lesion. It's usually caused by a trauma which places the epidermal fragments inside the bone. 31-year-old female patient was presented with a mass in the distal phalanx of the 3rd digit of the right hand. The histological examination following the excision of the cyst revealed intraosseous epidermoid cyst. Histopathological features, patient demographics, history, treatment, and prognosis of this rare case are presented.

A cynomolgus macaque presented with an osteolytic lesion of the left femur. Histopathology was consistent with well‐differentiated chondrosarcoma. No metastasis was found in chest radiographs out to 12 months. This case suggests survival out to 1 year without metastasis following amputation may be possible in NHPs with this condition. [ABSTRACT FROM AUTHOR]

Background: Limb salvage reconstruction for pelvic tumors, especially periacetabular tumors, is challenging. We combined the use of dual mobility bearing and 3D-printed hemipelvic prosthesis to improve function and reduce the probability of complications after hemi-pelvic resection in patients with primary acetabular malignancy. The purpose of this study was to evaluate the efficacy and safety of this combination.Methods: Between October 2011 and May 2021, 11 patients with malignancies involving the acetabulum received hemipelvic replacement with a 3D-printed prosthesis and dual mobility bearing. Follow-up of postoperative survival, complications, and Musculoskeletal Tumor Society 93 (MSTS-93) lower limb functional scores were carried out. A finite element model of the postoperative pelvis was developed and input into the finite element analysis software. The Von Mises equivalent stress formula was used to analyze the stress distribution of each part of the pelvis under one gait cycle and the stress distribution at different angles of the hip joint.Results: By the last follow-up, 9 of the 11 patients (81.8%) were still alive, and 2 patients had local tumor recurrence. The complications including 1 deep infection and 1 dislocation of the artificial joint. Excluding 1 amputation patient, the average score of the remaining 8 patients at the last follow-up was 21.4/30 (71.3%) on the MSTS-93. In the reconstructed pelvis, stress distributions were concentrated on the junction between hemipelvic prosthesis and screw and iliac bone on the resected side, and between femoral prosthesis stem and femoral bulb, while the stress of polyethylene lining was small. Before impact, the polyethylene lining will rotate at a small angle, about 3°. The inner stress of polyethylene liner is greater than the outer stress in all conditions. The polyethylene liner has no tendency to slide out.Conclusion: Pelvic tumor resection and reconstruction using 3D-printed hemipelvic prosthesis combined with dual mobility bearing was an effective treatment for pelvic tumors. Our patients achieved good early postoperative efficacy and functional recovery. The dual mobility bearing is beneficial to prevent dislocation, and the mechanical distribution and wear of the prosthesis are acceptable. [ABSTRACT FROM AUTHOR]

Simple Summary: Giant cell tumor of bone (GCTB) is an intermediate bone neoplasm which consists of several cell populations, including the neoplastic "stromal" cells. These cells harbor a mutation in one of the histone H3.3 genes (H3F3A), and are therefore considered as the driving component of GCTB. This mutation causes changes in the epigenetic landscape, leading to aberrant gene expression patterns that may drive tumor growth. Surgery is currently the only curative treatment option because contemporary systemic therapies cannot remove the neoplastic cells from GCTB lesions, leading to re-outgrowth of the tumor when the treatment is discontinued. Therefore, the aim of this study was to explore whether therapeutic targeting of the epigenome can eliminate the neoplastic cells from GCTB lesions. The findings from this study indicate that histone deacetylase (HDAC) inhibitors may represent such a treatment strategy, which could improve the quality of life of GCTB patients who currently require life-long treatment. The neoplastic "stromal" cells in giant cell tumor of bone (GCTB) harbor a mutation in the H3F3A gene, which causes alterations in the epigenome. Current systemic targeted therapies, such as denosumab, do not affect the neoplastic cells, resulting in relapse upon treatment discontinuation. Therefore, this study examined whether targeting the epigenome could eliminate the neoplastic cells from GCTB. We established four novel cell lines of neoplastic "stromal" cells that expressed the H3F3A p.G34W mutation. These cell lines were used to perform an epigenetics compound screen (n = 128), which identified histone deacetylase (HDAC) inhibitors as key epigenetic regulators in the neoplastic cells. Transcriptome analysis revealed that the neoplastic cells expressed all HDAC isoforms, except for HDAC4. Therefore, five HDAC inhibitors targeting different HDAC subtypes were selected for further studies. All GCTB cell lines were very sensitive to HDAC inhibition in both 2D and 3D in vitro models, and inductions in histone acetylation, as well as apoptosis, were observed. Thus, HDAC inhibition may represent a promising therapeutic strategy to eliminate the neoplastic cells from GCTB lesions, which remains the paramount objective for GCTB patients who require life-long treatment with denosumab. [ABSTRACT FROM AUTHOR]

Introduction: We aimed to identify imaging‐based findings that can differentiate between spinal subchondral bone metastasis with focal pathologic endplate fracture and oedematous Schmorl's nodes that have been histopathologically confirmed. Methods: Between March 2010 and April 2016, 11 patients who had undergone spinal magnetic resonance (MR) imaging or computed tomography (CT) with final radiologic reports that included 'subchondral bone metastasis with focal pathologic endplate fracture' or 'edematous Schmorl's node' and had also undergone percutaneous imaging‐guided spinal biopsies were included. Two radiologists retrospectively evaluated the following imaging features in consensus: size, location, presence of sclerotic margin, presence of intralesional or perilesional enhancement and opposite endplate enhancement of the involved disc, presence of disc height loss and presence of metabolic uptake at a corresponding lesion on nuclear medicine imaging. Results: A total of 11 patients, including six patients with spinal subchondral bone metastasis with focal pathologic endplate fracture and five patients with oedematous Schmorl's nodes, were included in this study (median age, 58 years; range, 50–63 years; six men). Sclerotic margin (P = 0.002) and enhancement on the opposite endplate of the involved disc (P = 0.047) were significantly different between oedematous Schmorl's node and subchondral bone metastasis with focal pathologic endplate fracture. Conclusion: Sclerotic margin and enhancement on the opposite endplate of the involved disc suggest oedematous Schmorl's node rather than subchondral bone metastasis with focal pathologic endplate fracture. Decreased disc height is likely to be an oedematous Schmorl's node rather than subchondral bone metastasis with focal pathologic endplate fracture. [ABSTRACT FROM AUTHOR]

Introduction: Bone neoplasms represent a diverse group of malignancies that significantly impact morbidity and mortality. These tumors primarily affect the appendicular skeleton and, while less common than other malignancies, are particularly notable due to their prevalence in adolescents and young adults. Given their potential for rapid growth and high metastatic potential, these neoplasms can be life-threatening. This study aims to explore the relative frequencies, age, and sex distributions, as well as the anatomical and clinico-pathological characteristics of bone tumors in a tertiary care hospital., Materials and Methods:  This retrospective cross-sectional study was conducted in the histopathology section of the Department of Pathology at a tertiary care medical college in Western India over 18 months (January 2023 to June 2024). All histopathologically confirmed cases of bone tumors, both benign and malignant, were analyzed based on the WHO's recent fifth-edition classification. Clinical data, including age, sex, and anatomical site, along with radiological investigations, were also reviewed for final diagnosis., Results:  A total of 63 patients, ranging from three months to 66 years old, with a mean age of 25.8 years, were included in the study. Of these, 34 (53.9%) were male and 29 (46.03%) were female, resulting in a male-to-female ratio of 1.17:1. The highest incidence of primary bone tumors occurred in the 11-20 years age group. Benign tumors accounted for 36 cases (57.11%), while 27 cases (42.85%) were malignant. Giant cell tumors (GCTs) were the most common, with 12 cases (19.04%), followed by osteochondroma with 11 cases (17.46%). Among malignant tumors, osteosarcoma was the most frequent, with 11 cases (17.46%), followed by Ewing's sarcoma with 10 cases (15.87%)., Conclusion:  The majority of tumors in this cohort were benign, with a slight male predominance, particularly among young adults. The diagnosis of bone tumors requires a comprehensive approach, including clinical evaluation, radiological correlation, and histopathological examination (HPE). In certain cases, immunohistochemistry is essential for an accurate diagnosis, staging, and the development of an effective treatment plan., Competing Interests: Human subjects: Consent for treatment and open access publication was obtained or waived by all participants in this study. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Mohapatro et al.)

CT-guided bone biopsies are currently the diagnostic tool of choice for histopathological (and microbiological) diagnoses of skeletal lesions. Several research works have well-demonstrated their safety and feasibility in almost all skeletal regions. This comprehensive review article aims at summarizing the general concepts in regard to bone biopsy procedures, current clinical indications, the feasibility and the diagnostic yield in different skeletal sites, particularly in the most delicate and difficult-to-reach ones. The choice of the correct imaging guidance and factors affecting the diagnostic rate, as well as possible complications, will also be discussed. Since the diagnostic yield, technical difficulties, and complications risk of a CT-guided bone biopsy significantly vary depending on the different skeletal sites, subdivided analyses of different anatomical sites are provided. The information included in the current review article may be useful for clinicians assisting patients with possible bone neoplasms, as well as radiologists involved in the imaging diagnoses of skeletal lesions and/or in performing bone biopsies.

Objectives: The purpose of the study was to compare clinical and radiological outcomes of autografts obtained from the iliac crest (IC) and distal radius (DR) and to evaluate their superiority for surgical treatment of solitary finger enchondromas. Methods: Twenty-five patients for whom curettage and autografting were carried out for finger enchondroma were retrospectively analyzed. DR autograft was used in eight patients and IC autograft was used in 17 patients. Data on pre-operative total active motion (TAM), disabilities of the arm, shoulder, and hand (DASH) score, and pain visual analog scale (VAS) scores of the involved finger, duration of surgery, amount of bleeding during the operation, length of hospital stay, presence of complications related to anesthesia, and post-operative donor site morbidity were obtained. Pre-operative and post-operative 12th month radiographies were evaluated for pre-operative tumor volume, post-operative remnant volume, and Tordai radiologic evaluation grade. Results: No statistically significant difference could be identified between post-operative TAM (p=0.154), DASH (p=0.458), pain VAS scores (p=0.571), remnant volume (p=0.496), Tordai radiologic evaluation grade (p=0.522), duration of surgery (p=0.288), and amount of bleeding (p=0.114) between DR and IC groups. However, mean hospital stay duration was shorter for the DR group (p=0.0001). Recurrence was observed in one patient in the DR group and three patients in the IC group (p=0.996). Conclusion: The clinical and radiological outcomes of grafting from the DR and IC were similar in the treatment of hand enchondromas. However, grafting from the DR may result in shorter hospital stay compared to IC grafting. [ABSTRACT FROM AUTHOR]

The phase III clinical study of adjuvant liposomal muramyl tripeptide (MTP-PE) in resected high-grade osteosarcoma (OS) documented positive results that have been translated into regulatory approval, supporting initial promise for innate immune therapies in OS. There remains, however, no new approved treatment such as MTP-PE for either metastatic or recurrent OS. Whilst the addition of different agents, including liposomal MTP-PE, to surgery for metastatic or recurrent high-grade osteosarcoma has tried to improve response rates, a mechanistic hiatus exists in terms of a detailed understanding the therapeutic strategies required in advanced disease. Here we report a Bayesian designed multi-arm, multi-centre, open-label phase II study with randomisation in patients with metastatic and/or recurrent OS, designed to investigate how patients with OS might respond to liposomal MTP-PE, either given alone or in combination with ifosfamide. Despite the trial closing because of poor recruitment within the allocated funding period, with no objective responses in eight patients, we report the design and feasibility outcomes for patients registered into the trial. We demonstrate the feasibility of the Bayesian design, European collaboration, tissue collection with genomic analysis and serum cytokine characterisation. Further mechanistic investigation of liposomal MTP-PE alone and in combination with other agents remains warranted in metastatic OS. [ABSTRACT FROM AUTHOR]

(1) Background: The purpose of this study is to evaluate the impact of an augmented reality navigation system (SIRIO) for percutaneous biopsies and ablative treatments on bone lesions, compared to a standard CT-guided technique. (2) Methods: Bioptic and ablative procedures on bone lesions were retrospectively analyzed. All procedures were divided into SIRIO and Non-SIRIO groups and in 2 cm groups. Number of CT-scans, procedural time and patient’s radiation dose were reported for each group. Diagnostic accuracy was obtained for bioptic procedures. (3) Results: One-hundred-ninety-three procedures were evaluated: 142 biopsies and 51 ablations. Seventy-four biopsy procedures were performed using SIRIO and 68 under standard CT-guidance; 27 ablative procedures were performed using SIRIO and 24 under standard CT-guidance. A statistically significant reduction in the number of CT-scans, procedural time and radiation dose was observed for percutaneous procedures performed using SIRIO, in both 2 cm groups. The greatest difference in all variables examined was found for procedures performed on lesions

Background: The purpose of this study was to evaluate the implant survival, functional score and complications of intercalary endoprostheses implanted for metastatic involvement of the femoral and humeral diaphysis. Methods: The selected group covered patients with bone metastasis who were surgically treated with an intercalary endoprosthesis between 2012 and 2021. The functional outcome was evaluated with the Musculoskeletal Tumor Society (MSTS) scoring system, and complications were evaluated by using the failure classification for prosthetics designed by Henderson. Results: The mean follow-up was 29.8 months. In our group of 25 patients with 27 intercalary endoprostheses (18 femurs, 9 humeri), there were 7 implant-related complications (25.9%), which were more common on the humerus (4 cases, 44.4%) than on the femur (3 cases, 16.7%). Only type II failure—aseptic loosening (5 cases, 18.5%)—and type III failure—structural failure (2 cases, 7.4%)—occurred. There was a significantly higher risk of aseptic loosening of the endoprosthesis in the humerus compared with that in the femur (odds ratio 13.79, 95% confidence interval 1.22–151.05, p = 0.0297). The overall cumulative implant survival was 92% 1 year after surgery and 72% 5 years after surgery. The average MSTS score was 82%. The MSTS score was significantly lower (p = 0.008) in the humerus (75.9%) than in the femur (84.8%). Conclusions: The resection of bone metastases and replacement with intercalary endoprosthesis has excellent immediate functional results with an acceptable level of complications in prognostically favourable patients. [ABSTRACT FROM AUTHOR]

In this study, the effect of heterozygous germline mutations in the heparan sulfate (HS) glycosaminoglycan chain co-polymerases EXT1 and EXT2 on glomerular barrier function and the endothelial glycocalyx in humans is investigated. Heparan sulfate (HS) glycosaminoglycans are deemed essential to the glomerular filtration barrier, including the glomerular endothelial glycocalyx. Animal studies have shown that loss of HS results in a thinner glycocalyx. Also, decreased glomerular HS expression is observed in various proteinuric renal diseases in humans. A case report of a patient with an EXT1 mutation indicated that this could result in a specific renal phenotype. This patient suffered from multiple osteochondromas, an autosomal dominant disease caused by mono-allelic germline mutations in the EXT1 or EXT2 gene. These studies imply that HS is indeed essential to the glomerular filtration barrier. However, loss of HS did not lead to proteinuria in various animal models. We demonstrate that multiple osteochondroma patients do not have more microalbuminuria or altered glycocalyx properties compared to age-matched controls (n = 19). A search for all Dutch patients registered with both osteochondroma and kidney biopsy (n = 39) showed that an EXT1 or EXT2 mutation does not necessarily lead to specific glomerular morphological phenotypic changes. In conclusion, this study shows that a heterozygous mutation in the HS backbone elongating enzymes EXT1 and EXT2 in humans does not result in (micro)albuminuria, a specific renal phenotype or changes to the endothelial glycocalyx, adding to the growing knowledge on the role of EXT1 and EXT2 genes in pathophysiology. [ABSTRACT FROM AUTHOR]

Osteoid osteoma is a benign osteoblastic tumour constituting 10-20% of all benign tumours. It is rarely seen in the foot and accounts for approximately 4% of all cases. The present case was of a 23-years old male with an osteoid osteoma in the lateral cortex of his medial cuneiform at the articulating surface. He was misdiagnosed for nine-months with initial radiographs and Magnetic Resonance Imaging (MRI) failing to diagnosis the tumour. Extensive conservative treatment failed to resolve his symptoms, although Non-Steroidal Anti-Inflammatory Drug (NSAID) provided relief. Treatment involved excising the osteoid osteoma and filling the void left from the tumour with a synthetic bone graft.

Intraosseous epidermoid cyst is a rare nonneoplastic lesion. It’s usually caused by a trauma which places the epidermal fragments inside the bone. 31‑year‑old female patient was presented with a mass in the distal phalanx of the 3rd digit of the right hand. The histological examination following the excision of the cyst revealed intraosseous epidermoid cyst. Histopathological features, patient demographics, history, treatment, and prognosis of this rare case are presented. [ABSTRACT FROM AUTHOR]

High-grade osteosarcoma, a primary malignant bone tumour, is experiencing a global increase in reported incidence with varied prevalence. Despite advances in management, which include surgery and neoadjuvant chemotherapy often an unsatisfactory outcome is found due to poor or heterogeneous response to chemotherapy. Our study delved into chemotherapy responses in osteosarcoma patients and associated molecular expressions, focusing on CD95 receptor (CD95R), interferon (IFN)-γ, catalase, heat-shock protein (Hsp)70, and vascular endothelial growth factor (VEGF). Employing immunohistochemistry and Huvos grading of post-chemo specimens, we analysed formalin-fixed paraffin-embedded (FFPE) osteosarcoma tissue of resected post-chemotherapy specimens from Dr. Soetomo General Academic Hospital in Surabaya, Indonesia (DSGAH), spanning from 2016 to 2020. Results revealed varied responses (poor 40.38%, moderate 48.08%, good 11.54%) and distinct patterns in CD95R, IFN-γ, catalase, Hsp70, and VEGF expression. Significant differences among response groups were observed in CD95R and IFN-γ expression in tumour-infiltrating lymphocytes. The trend of diminishing CD95R expression from poor to good responses, accompanied by an increase in IFN-γ, implied a reduction in the count of viable osteosarcoma cells with the progression of Huvos grading. Catalase expression in osteosarcoma cells was consistently elevated in the poor response group, while Hsp70 expression was highest. VEGF expression in macrophages was significantly higher in the good response group. In conclusion, this study enhances our understanding of immune-chemotherapy interactions in osteosarcoma and identifies potential biomarkers for targeted interventions., (© 2024. The Author(s).)

Background: Diffusion-weighted imaging (DWI) has been described to correlate with tumoural necrosis in response to preoperative chemotherapy for osteosarcoma. Objective: To assess the accuracy of DWI in evaluating the response to neoadjuvant chemotherapy at the mid-course treatment of long-bone osteosarcoma and in predicting survival. Materials and methods: We conducted a prospective single-centre study over a continuous period of 11 years. Consecutive patients younger than 20 years treated with a neoadjuvant regimen for peripheral conventional osteosarcoma were eligible for inclusion. Magnetic resonance imaging (MRI) with DWI was performed at diagnosis, and mid- and end-course chemotherapy with mean apparent diffusion coefficients (ADC) calculated at each time point. A percentage less than or equal to 10% of the viable residual tissue at the histological analysis of the surgical specimen was defined as a good responder to chemotherapy. Survival comparisons were calculated using the Kaplan-Meier method. Uni- and multivariate analyses with ADC change were performed by Cox modelling. This is an expansion and update of our previous work. Results: Twenty-six patients between the ages of 4.8 and 19.6 years were included, of whom 14 were good responders. At mid-course chemotherapy, good responders had significantly higher mean ADC values (P=0.046) and a higher increase in ADC (P=0.015) than poor responders. The ADC change from diagnosis to mid-course MRI did not appear to be a prognosticator of survival and did not impact survival rates of both groups. Conclusion: DWI at mid-course preoperative chemotherapy for osteosarcoma should be considered to evaluate the degree of histological necrosis and to predict survival. The anticipation of a response to neoadjuvant treatment by DWI may have potential implications on preoperative management. [ABSTRACT FROM AUTHOR]

(1) Background: The purpose of this study is to evaluate the impact of an augmented reality navigation system (SIRIO) for percutaneous biopsies and ablative treatments on bone lesions, compared to a standard CT-guided technique. (2) Methods: Bioptic and ablative procedures on bone lesions were retrospectively analyzed. All procedures were divided into SIRIO and Non-SIRIO groups and in <2 cm and >2 cm groups. Number of CT-scans, procedural time and patient’s radiation dose were reported for each group. Diagnostic accuracy was obtained for bioptic procedures. (3) Results: One-hundred-ninety-three procedures were evaluated: 142 biopsies and 51 ablations. Seventy-four biopsy procedures were performed using SIRIO and 68 under standard CT-guidance; 27 ablative procedures were performed using SIRIO and 24 under standard CT-guidance. A statistically significant reduction in the number of CT-scans, procedural time and radiation dose was observed for percutaneous procedures performed using SIRIO, in both <2 cm and >2 cm groups. The greatest difference in all variables examined was found for procedures performed on lesions <2 cm. Higher diagnostic accuracy was found for all SIRIO-assisted biopsies. No major or minor complications occurred in any procedures. (4) Conclusions: The use of SIRIO significantly reduces the number of CT-scans, procedural time and patient’s radiation dose in CT-guided percutaneous bone procedures, particularly for lesions <2 cm. An improvement in diagnostic accuracy was also achieved in SIRIO assisted biopsies. [ABSTRACT FROM AUTHOR]

A T1 sequence on routine baseline staging rectal magnetic resonance imaging (MRI) is thought to help detect bone lesions. Our primary aim was to evaluate the incidence of bone lesions encountered on baseline staging rectal MRI, particularly the prevalence of bone metastases. This retrospective study included patients with rectal adenocarcinoma who underwent baseline rectal MRI at our institution between January 2010 and December 2017. The MRI report was reviewed for presence of bone lesions. When found, lesion type, presence of axial T1 non-fat-suppressed sequence, primary tumor T-stage, and presence of other organ metastases were recorded. In the absence of bone biopsy, the reference standard was follow-up imaging via computed tomography (CT), MRI, and/or positron emission tomography/CT (PET/CT) ≥ 1 year after the baseline MRI. The Wilcoxon rank-sum test and Fisher's exact test were used to compare clinicopathologic data of patients with malignant or benign bone lesions. A total of 1197 patients were included. 62/1197 patients (mean age 56.8 years (SD: 13.8), with 39 men) had bone lesions on baseline imaging, with 6 being bone metastases (0.5%, 95% CI 0.2%–1.1%). Of the 6 patients with bone metastases, 5/6 had other metastases (i.e., liver, lung) at baseline. Bone metastases on baseline rectal MRI performed for rectal adenocarcinoma are extremely rare. Furthermore, bone metastases without other organ (i.e., liver, lung) involvement is extremely rare. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective: Hemipelvectomy is a complex surgery with a high complication rate. Here, we aimed to identify factors related to the onset of complications and calculate their impacts on hospital costs. Methods: We evaluated 31 consecutive patients who underwent hemipelvectomy between 1999 and 2015. We assessed the clinical and radiographic data to determine the patients’ demographic factors, tumor and surgical characteristics, and complications. The individual hospital stays and financial balances were assessed up to 6 months following the index surgery. Results: The overall complication rate was 61% (19/31). Infection was the most prevalent complication (36%). Immediate postoperative death occurred in 5/31 patients (16%); another 5 (16%) died after hospital discharge due to disease progression. Histological grade, previous surgery, and previous radiotherapy were not associated with complications or infection. Acetabular resections, bone reconstruction, and longer operative times were associated with infection, whereas older age, pelvic organ involvement, and comorbidities were associated with immediate postoperative death. Complications and infection were associated with 4.8- and 5.9-fold increases in hospital costs, respectively. Conclusions: Acetabular resection and bone reconstruction are important factors that increase short-term complication rates, infection rates, and hospital costs. Mortality was associated with older age and adjacent pelvic tumor progression. Level of Evidence: IV, case series.

Abstract Background The aim of the present study was to explore whether control of balance and other factors were associated with functional recovery and walking performance in the short term in a group of patients receiving modular knee endoprosthetic reconstruction following bone tumour resection in order to provide effective suggestions for a new rehabilitation protocol. Methods A cross-sectional study was carried out in the chemotherapy ward of an Italian hospital specialized in bone cancer. All patients consecutively treated using a modular knee endoprosthetic between January 2013 and February 2014 were included in the study. One year after surgery, various measuring instruments were used to assess the functional outcome achieved: Musculoskeletal Tumor Society rating scale, Toronto Extremity Salvage Score and specific motor tests of gait, such as gait speed and resistance. Data concerning the variables involved are as follows: bone resection, knee joint range of motion, quadriceps muscle strength and posture control. Statistical tests included correlation analysis (Pearson and Spearman correlation). Results Balance control was significantly correlated to all the gait tests performed. Age, duration of chemotherapy and strength of the knee extensor muscles also showed a correlation. Conversely, joint range of motion and resection percentage did not show a significant correlation. Conclusions Rehabilitation in patients undergoing knee joint reconstruction due to cancer should include balance control exercises, which involve not only the treated limb but address the entire sensory and motor system. This extends beyond the concept of treatment aimed at improving individual functions such as joint range of motion and muscular strength.

Myxoid chondrosarcoma is a rare malignant neoplasm of bone or soft tissue origin, characterised by the presence of chondroid and myxoid matrix. These are traditionally radio resistant tumours, so wide surgical resection remains the mainstay of treatment. However, radiotherapy is generally advised for high-grade lesions with poor prognostic factors with adjuvant chemotherapy. The treatment decisions are primarily guided by the histological grade, extent of surgical resection, and site of the neoplasm. A case of a 28-year-old male who presented with recurrent painful swelling in the mandibular region is discussed here. To date, very few cases of Extraskeletal Myxoid Chondrosarcoma (EMC) occurring in the mandible region have been reported. So, due to the paucity of available literature, controversies still exist regarding effective treatment approaches in newly diagnosed and recurrent cases. This case reports the clinical presentation, histopathology, radiological characteristics, immune profile, and treatment modalities used in EMC with a comprehensive and relevant review of the literature.

PICO question What is the sensitivity and specificity of cytology as a test for canine osteosarcoma when compared to histopathology as a gold standard? Clinical bottom line Category of research question Diagnosis The number and type of study designs reviewed Overall, four diagnostic validity studies (two prospective and two retrospective) were critically appraised Strength of evidence Weak to moderate Outcomes reported There is evidence of moderate strength to support that cytology is highly sensitive and specific for diagnosing histologically confirmed osteosarcomas as mesenchymal malignant neoplasms (cytological diagnosis of sarcoma). Evidence of weak strength suggests that the sensitivity and specificity of cytology for identifying the exact histotype (cytological diagnosis of osteosarcoma) are low and high, respectively. Finally, there is currently evidence of weak strength indicating that the sensitivity and specificity of cytology are comparable to that of preoperative histopathology after incisional biopsy for the diagnosis of canine osteosarcoma Conclusion Based on the available evidence, the diagnostic accuracy of cytology in diagnosing histologically confirmed osteosarcomas as sarcomas is high, whereas a confident conclusion cannot be drawn regarding the diagnostic accuracy of cytology for the identification of the exact histotype (cytological diagnosis of osteosarcoma). There is currently scant evidence suggesting that cytology has comparable diagnostic accuracy to preoperative histopathology (i.e. after incisional biopsy) for the diagnosis of canine osteosarcomas, however, more studies are warranted to confirm these results How to apply this evidence in practice The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources. Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.

Primary sclerosing epithelioid fibrosarcoma (SEF) of bone is a rare and scarcely reported neoplasm. We document clinicopathological and molecular features of 9 additional cases. Five males and 4 females had a mean age of 39 years (14–71 years). Most tumors affected flat/irregular bones; only 3 cases involved a long bone. By radiology, it has characteristic radiographic features of a predominantly lytic expansile lesion with a sclerotic rim. Referring diagnoses were SEF (n = 2), low-grade osteosarcoma (n = 2), chondrosarcoma (n = 1), and chondromyxoid fibroma (n = 1). Histologically, five cases revealed classical morphology of SEF of soft tissue. Remaining cases were classified as hybrid SEF/low-grade fibromyxoid sarcoma, characterized by spindle or stellate cells, prominent stroma, and giant hyalinized areas. Various morphological deviations such as prominent vasculature (n = 3), osteoid-like material (n = 4), or parallel bone trabeculae (n = 2) were observed. Immunohistochemically, all cases showed diffuse and strong MUC4 expression. SATB2 was observed in 5/8 cases. Using FISH, EWSR1, and FUS rearrangements were detected in 4 cases and 1 case, respectively. EWSR1-CREB3L1 fusion was identified in 1 additional case by next-generation sequencing. Recurrence and metastasis were observed in 1 case and 2 cases, respectively. All but one patient were alive with disease for a mean interval of 31 months. SEF of bone is a relatively indolent sarcoma of adults, most commonly located in the flat/irregular bones. Due to overlapping histological features, it is often misdiagnosed as osteosarcoma or a chondroid tumor. Most SEF of bone exhibit EWSR1 rearrangements, but rare cases may harbor a FUS gene fusion. [ABSTRACT FROM AUTHOR]

Introduction: Perivascular epithelioid cell tumors (PEComas) are a family of mesenchymal tumors that rarely arise as a primary bone tumor. Material and methods: We report a case of primary malignant bone PEComa. A literature review via PubMed, Embase and Web of Science databases with the keyword “PEComa” and “bone” was performed. Results: We reported a 33-year-old female with primary malignant bone PEComa in right distal humerus. The patient received an inhibitor of the mammalian target of rapamycin (mTOR) protein based on negative molecular investigation result of transcription factor E3 (TFE3) rearrangement, and additional therapies including palliative radiotherapy, anti-angiogenics and immunotherapy when the disease progression was detected. The patient was alive with the disease twenty-three months postoperatively. A total of nineteen related literature cases were retrieved and reviewed. Taking current case into account, ten males and ten females with median age of 24 years (range, 3–93 years) were identified, who were most frequently affected in tibia. The median follow-up duration of 24 months (range, 3–96 months). One patient died due to this disease, and six patients showed metastases. Three patients experienced recurrence, and two of them experienced twice and three times, respectively. Conclusion: To our knowledge, this is the first case of primary malignant bone PEComa arising in humerus. Clinicopathological and radiological correlation is mandatory to the correct diagnosis and to determine its malignancy. More studies are required to understand the role of molecular test and imaging in selecting suitable treatment and mechanisms of treatment resistance.

Purpose: To evaluate the correlation of maximum standardized uptake values (SUVmax) of 18F-Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) with the apparent diffusion coefficient (ADC) of diffusion weighted imaging (DWI) in musculoskeletal malignancies. Methods: Institutional ethics committee approved this retrospective study. Twenty-seven patients (mean age: 44.85 ± 24.07; 17 men and 10 women) with a total of 29 musculoskeletal tumors underwent both FDG-PET/CT and DWI between January 2017 and March 2020. Region-of-interest (ROI)-based maximal standardized uptake values (SUVmax) of the tumors were measured on FDG-PET/CT images. Two radiologists measured lesions’ mean and minimum apparent diffusion coefficient (ADCmean and ADCmin) using five distinct ROIs on DWI images. Pearson correlation analysis was used to assess the correlation between SUVmax and ADC values. Results: There were 18 soft tissue tumors (62.1%) and 11 bone tumors (37.9%) with a mean maximum diameter of 9.4 ± 6.2 cm. The mean SUVmax, ADCmean and ADCmin of the whole lesions were 12.93 ± 9.63, 0.85 ± 0.28 × 10–3mm2/s and 0.61 ± 0.27 × 10–3mm2/s, respectively. SUVmax had a weak correlation with tumor maximum diameter (r = 0.378, p = 0.043), whereas ADCmean and ADCmin had none. There was strong inverse correlation between SUVmax and both ADCmean (r = –0.616, p < 0.001) and ADCmin (r = –0.638, p < 0.001). Conclusion: In musculoskeletal tumors, quantitative markers of FDG uptake and diffusion restriction strongly correlate.

Background: Atypical cartilaginous tumour (ACT) and high-grade chondrosarcoma (CS) of long bones are respectively managed with active surveillance or curettage and wide resection. Our aim was to determine diagnostic performance of X-rays radiomics-based machine learning for classification of ACT and high-grade CS of long bones., Methods: This retrospective, IRB-approved study included 150 patients with surgically treated and histology-proven lesions at two tertiary bone sarcoma centres. At centre 1, the dataset was split into training (n = 71 ACT, n = 24 high-grade CS) and internal test (n = 19 ACT, n = 6 high-grade CS) cohorts, respectively, based on the date of surgery. At centre 2, the dataset constituted the external test cohort (n = 12 ACT, n = 18 high-grade CS). Manual segmentation was performed on frontal view X-rays, using MRI or CT for preliminary identification of lesion margins. After image pre-processing, radiomic features were extracted. Dimensionality reduction included stability, coefficient of variation, and mutual information analyses. In the training cohort, after class balancing, a machine learning classifier (Support Vector Machine) was automatically tuned using nested 10-fold cross-validation. Then, it was tested on both the test cohorts and compared to two musculoskeletal radiologists' performance using McNemar's test., Findings: Five radiomic features (3 morphology, 2 texture) passed dimensionality reduction. After tuning on the training cohort (AUC = 0.75), the classifier had 80%, 83%, 79% and 80%, 89%, 67% accuracy, sensitivity, and specificity in the internal (temporally independent) and external (geographically independent) test cohorts, respectively, with no difference compared to the radiologists (p ≥ 0.617)., Interpretation: X-rays radiomics-based machine learning accurately differentiates between ACT and high-grade CS of long bones., Funding: AIRC Investigator Grant., Competing Interests: Declaration of interests Matteo Interlenghi: CTO and employee of DeepTrace Technologies. DeepTrace Technologies is a spin-off of Scuola Universitaria Superiore IUSS, Pavia, Italy; shareholder in DeepTrace Technologies. Christian Salvatore: CEO of DeepTrace Technologies. DeepTrace Technologies is a spin-off of Scuola Universitaria Superiore IUSS, Pavia, Italy; shareholder in DeepTrace Technologies. Isabella Castiglioni: Shareholder in DeepTrace Technologies. All other authors declare that they have no conflicts of interest to disclose., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Osteoblastoma (OSB) is an uncommon (3% of benign and 1% of all) primary bone neoplasm with extremely rare occurrence in head and neck, especially the maxillary bone region. OSB of the jaw mainly involves the mandible bone. We report a 10-month-old male who was admitted to the hospital because of a mass in the right maxillary jaw region. Clinicoradiopathologic features of the patient have been described. The histological examinations revealed OSB of the maxillary bone. Total surgical resection of the tumor was performed with 10 months of follow-up and there is no evidence of recurrence. To the best of our knowledge, it is the first report of maxillary OSB in an infant.

Bone metastasis is the third most common extrahepatic metastasis from hepatocellular carcinoma (HCC), following lung and lymph node metastasis. Although transcatheter arterial chemoembolization (TACE) is widely used for the treatment for unresectable HCC in the liver, its effects on bone metastasis from HCC have not been well described in past literature. We report a case of a patient with a metastatic bone lesion from an HCC treated with TACE. After the procedure, the patient's pain and narcotic requirement significantly decreased without major complications.