PSMA-PET follow-up to assess response in patients not receiving PSMA therapy: Is there value beyond localization of disease?

Introduction: Prostate Specific Membrane Antigen Positron Emission Tomography (PSMA-PET) is routinely used for the staging of patients with prostate cancer, but data on response assessment are sparse and primarily stem from metastatic castration-resistant prostate cancer (mCRPC) patients treated with PSMA radioligand therapy. Still, follow-up PSMA-PET is employed in earlier disease stages in case of clinical suspicion of disease persistence, recurrence or progression to decide if localized or systemic treatment is indicated. Therefore, the prognostic value of PSMA-PET derived tumor volumes in earlier disease stages (i.e., hormone-sensitive prostate cancer (HSPC) and non-[177Lu]Lu-PSMA-617 (LuPSMA) therapy castration resistant prostate cancer (CRPC)) are evaluated in this manuscript. Methods: A total number of 73 patients (6 primary staging, 42 HSPC, 25 CRPC) underwent two (i.e., baseline and follow-up, median interval: 379 days) whole-body [68Ga]Ga-PSMA-11 PET/CT scans between Nov 2014 and Dec 2018. Analysis was restricted to non-LuPSMA therapy patients. PSMA-PETs were retrospectively analyzed and primary tumor, lymph node-, visceral-, and bone metastases were segmented. Body weight-adjusted organ-specific and total tumor volumes (PSMAvol: sum of PET volumes of all lesions) were measured for baseline and follow-up. PSMAvol response was calculated as the absolute difference of whole-body tumor volumes. High metastatic burden (>5 metastases), RECIP 1.0 and PSMA-PET Progression Criteria (PPP) were determined. Survival data were sourced from the cancer registry. Results: The average number of tumor lesions per patient on the initial PET examination was 10.3 (SD 28.4). At baseline, PSMAvol was strongly associated with OS (HR 3.92, p <0.001; n = 73). Likewise, response in PSMAvol was significantly associated with OS (HR 10.48, p < 0.005; n = 73). PPP achieved significance as well (HR 2.19, p <0.05, n = 73). Patients with hormone sensitive disease and poor PSMAvol response (upper quartile of PSMAvol change) in follow-up had shorter outcome (p < 0.05; n = 42). PSMAvol in bones was the most relevant parameter for OS prognostication at baseline and for response assessment (HR 31.11 p < 0.001; HR 32.27, p < 0.001; n = 73). Conclusion: PPP and response in PSMAvol were significantly associated with OS in the present heterogeneous cohort. Bone tumor volume was the relevant miTNM region for OS prognostication. Future prospective evaluation of the performance of organ specific PSMAvol in more homogeneous cohorts seems warranted.

Gait analysis of patients undergoing knee endoprosthesis: functional differences between tibia and femur resections.

With the improvement in survival of patients undergoing knee reconstructive surgeries, the functional parameter became widely studied heading optimize and minimize motor sequelae. In patients undergoing knee endoprosthesis, proximal tibial or distal femoral resections affect the functioning of the knee extensor mechanism, with possible repercussions on gait. Seventeen patients were selected, divided into two groups, undergoing distal femoral or proximal tibial resection, and gait analysis examination was performed. Changes in gait velocity, cadence, step length, and alterations in the support and balance phase were observed. No major statistically significant differences were found in the kinetic and kinematic parameters between the operated groups. The study corroborates that although tibial resections have a higher theoretical risk of compromising the extensor mechanism, such data were not observed in the analyzed sample.

Quantitative Bone SPECT/CT of Central Cartilaginous Bone Tumors: Relationship between SUVmax and Radiodensity in Hounsfield Unit.

(1) Background: it is challenging to determine the accurate grades of cartilaginous bone tumors. Using bone single photon emission computed tomography (SPECT)/computed tomography (CT), maximum standardized uptake value (SUVmax) was found to be significantly associated with different grades of cartilaginous bone tumor. The inquiry focused on the effect of the tumor matrix on SUVmax. (2) Methods: a total of 65 patients from 2017 to 2022 with central cartilaginous bone tumors, including enchondromas and low-to-intermediate grade chondrosarcomas, who had undergone bone SPECT/CT were retrospectively enrolled. The SUVmax was recorded and any aggressive CT findings of cartilaginous bone tumor and Hounsfield units (HU) of the chondroid matrix as mean, minimum, maximum, and standard deviation (SD) were reviewed on CT scans. Pearson's correlation analysis was performed to determine the relationship between CT features and SUVmax. Subgroup analysis was also performed between the benign group (enchondroma) and the malignant group (grade 1 and 2 chondrosarcoma) for comparison of HU values and SUVmax. (3) Results: a significant negative correlation between SUVmax and HU measurements, including HUmax, HUmean, and HUSD, was found. The subgroup analysis showed significantly higher SUVmax in the malignant group, with more frequent CT aggressive features, and significantly lower HUSD in the malignant group than in the benign group. (4) Conclusions: it was observed that higher SUVmax and lower HUSD were associated with a higher probability of having a low-to-intermediate chondrosarcoma with aggressive features and a less calcified tumor matrix.

An Image-Guided Percutaneous Core Needle Biopsy for Accurate Assessment of Musculoskeletal Tumors: A Targeted Diagnosis.

Background Accurate diagnosis of musculoskeletal tumors is essential for guiding appropriate treatment strategies. Percutaneous core needle biopsy (PCNB) is increasingly recognized as a valuable method for obtaining tissue samples for histopathological examination. This study aims to evaluate the diagnostic accuracy and clinical utility of PCNB in diagnosing musculoskeletal tumors. Methodology A total of 152 cases suspected of musculoskeletal tumors underwent PCNB at our tertiary care center between 2020 and 2023. Pre-biopsy evaluation included comprehensive clinical assessment and imaging studies. Core biopsies were performed under image guidance, with specimens sent for histopathological examination and culture sensitivity analysis. Diagnostic yield, accuracy, and performance metrics of PCNB were assessed. Results PCNB demonstrated a diagnostic yield of 93.4%. However, in cases where initial biopsies were inconclusive, repeat core biopsy or open biopsy provided the necessary diagnostic clarity. PCNB demonstrated a remarkable diagnostic accuracy of 97.9%, with a specificity and positive predictive value of 100%. There were no post-biopsy complications and no instances of local recurrence from the biopsy tract. Conclusions PCNB can be a reliable method for diagnosing musculoskeletal tumors, offering high diagnostic accuracy and minimal complications. The utilization of image guidance enhances precision and reduces the risk of complications. PCNB proves effective in diagnosing both primary tumors and bone infections, facilitating timely and appropriate treatment strategies in orthopedic oncology.

Preliminary exploration of amide proton transfer weighted imaging in differentiation between benign and malignant bone tumors.

Purpose: To explore the value of 3D amide proton transfer weighted imaging (APTWI) in the differential diagnosis between benign and malignant bone tumors, and to compare the diagnostic performance of APTWI with traditional diffusion-weighted imaging (DWI). Materials and methods: Patients with bone tumors located in the pelvis or lower limbs confirmed by puncture or surgical pathology were collected from January 2021 to July 2023 in the First Affiliated Hospital of Zhengzhou University. All patients underwent APTWI and DWI examinations. The magnetization transfer ratio with asymmetric analysis at the frequency offset of 3.5 ppm [MTRasym(3.5 ppm)] derived by APTWI and the apparent diffusion coefficient (ADC) derived by DWI for the tumors were measured. The Kolmogorou-Smirnou and Levene normality test was used to confirm the normal distribution of imaging parameters; and the independent sample t test was used to compare the differences in MTRasym(3.5 ppm) and ADC between benign and malignant bone tumors. In addition, the receiver operating characteristic (ROC) curve was used to evaluate the diagnostic performance of different imaging parameters in differentiation between benign and malignant bone tumors. P<0.05 means statistically significant. Results: Among 85 bone tumor patients, 33 were benign and 52 were malignant. The MTRasym(3.5 ppm) values of malignant bone tumors were significantly higher than those of benign tumors, while the ADC values were significantly lower in benign tumors. ROC analysis shows that MTRasym(3.5 ppm) and ADC values perform well in the differential diagnosis of benign and malignant bone tumors, with the area under the ROC curve (AUC) of 0.798 and 0.780, respectively. Combination of MTRasym(3.5 ppm) and ADC values can further improve the diagnostic performance with the AUC of 0.849 (sensitivity = 84.9% and specificity = 73.1%). Conclusion: MTRasym(3.5 ppm) of malignant bone tumors was significantly higher than that of benign bone tumors, reflecting the abnormal increase of protein synthesis in malignant tumors. APTWI combined with DWI can achieve a high diagnostic efficacy in differentiation between benign and malignant bone tumors.

Primary Intraosseous Spindle Cell Rhabdomyosarcoma: A Case Report in an Unusual Location.

Spindle cell/sclerosing rhabdomyosarcoma is an infrequent subtype of rhabdomyosarcoma according to the World Health Organization Classification of Soft Tissue and Bone Tumours, which includes a novel category of intraosseous spindle-cell rhabdomyosarcomas (ISCRMS) with EWSR1:: or FUS::TFCP2 fusions. We report a case of ISCRMS with EWSR1::TFCP2 fusion presenting in the femur mimicking osteosarcoma in this unusual primary location. We present an 18-year-old male with relapsed widely metastatic sarcoma, morphologically identical to osteosarcoma responding poorly to chemotherapy, initially presenting in the distal femur. Sections showed a high-grade malignant neoplasm with sheets of epithelioid and spindled cells without obvious rhabdomyoblastic differentiation morphologically containing focal areas resembling new bone/osteoid formation. Molecular sequencing identified t(12;22) EWSR1::TFCP2. The tumor cells were diffusely positive for pancytokeratin, MyoD1, and ALK by retrospective immunohistochemistry. Desmin and SATB2 were focally positive. Myogenin was negative, and INI-1 expression was retained. ISCRMS commonly involves craniofacial and pelvic bones, but rarely originates in long bones, as in this case. Initially, osteosarcoma was the primary diagnostic consideration based on distal long bone location, patient age, and evidence of osteoid formation. Distinction between the two entities may be nearly impossible on morphologic grounds alone, which presents a diagnostic pitfall without molecular or extensive immunoprofiling data.

Total talar replacement for metastatic pulmonary adenocarcinoma of the talus: A case report.

Talar metastases from malignant tumors are rare and poorly documented. Treatment requires gradual relief of pain and preservation of function, with a choice between palliative measures and surgery. This case indicates that total talar replacement is an effective intervention for localized talar metastases and highlights the importance of early intervention. A 48-year-old man was diagnosed with a pathologic talar fracture due to talar metastases was observed after 8 years of chemotherapy following a diagnosis of lung adenocarcinoma. Despite radiotherapy, the patient's activities of daily living (ADLs) deteriorated due to pain on walking, prompting a request for surgical intervention. Total talar replacement was performed, allowing the patient to begin full weight-bearing ambulation 2 weeks post-operatively. Total talar replacement appears to be an effective treatment for localized talar metastases and should be performed as early as possible.

Pedunculated Osteochondroma Presenting as Verruca Vulgaris: A Diagnosis Requiring a High Index of Suspicion: Case Report.

Introduction: Osteochondromas are the most common benign tumors of the bone and can be sessile or pedunculated. Although osteochondromas are typically seen in the long bones, they are rarely seen in the small bones of the hand or foot. Verruca vulgaris, also known as the common wart, is one of the most common skin conditions presenting to physicians and must be distinguished either clinically or histologically from other hyperkeratotic conditions, including bone conditions such as bone tumors that can place pressure on the skin and cause callus formation that can mimic a wart or create skin deformity. A high index of suspicion for underlying bone mass or tumor should be entertained when evaluating patients for skin conditions, particularly of the hand or foot, with failure to improve with treatment. Case Report: This case report presents a 20-year-old male with a pedunculated osteochondroma of the left fourth distal phalanx with hyperkeratotic skin overlying the mass at the end of the toe. He was initially treated by a family doctor and podiatrist for verruca vulgaris for over 5 years with two treatments of liquid nitrogen cryotherapy and surgical excision of the mass when the treating podiatrist encountered bone and recommended radiographs. The family requested follow-up with our practice several days later after they were told the patient had a bone tumor. The patient requested surgical excision of the osteochondroma secondary to pain with activities and difficulties with his vocation as a pilot. Conclusion: All physicians must be mindful of an underlying bone tumor or mass in patients presenting with skin changes, particularly about the foot or hand. Knowledge that an underlying bone tumor can present as a verruca vulgaris may prevent a delay in diagnosis or unnecessary treatment when evaluating and treating a patient with a skin lesion. Fortunately, our case was a benign osteochondroma; a malignant tumor with a delay in diagnosis could lead to loss of limb or life.

Diagnostic performance and inter-reader reliability of bone reporting and data system (Bone-RADS) on computed tomography.

OBJECTIVE: To evaluate the diagnostic performance and inter-reader reliability of the Bone Reporting and Data System (Bone-RADS) for solitary bone lesions on CT. MATERIALS AND METHODS: This retrospective analysis included 179 patients (mean age, 56 ± 18 years; 94 men) who underwent bone biopsies between March 2005 and September 2021. Patients with solitary bone lesions on CT and sufficient histopathology results were included. Two radiologists categorized the bone lesions using the Bone-RADS (1, benign; 4, malignant). The diagnostic performance of the Bone-RADS was calculated using histopathology results as a standard reference. Inter-reader reliability was calculated. RESULTS: Bone lesions were categorized into two groups: 103 lucent (pathology: 34 benign, 12 intermediate, 54 malignant, and 3 osteomyelitis) and 76 sclerotic/mixed (pathology: 46 benign, 2 intermediate, 26 malignant, and 2 osteomyelitis) lesions. The Bone-RADS for lucent lesions had sensitivities of 95% and 82%, specificities of 11% and 11%, and accuracies of 57% and 50% for readers 1 and 2, respectively. The Bone-RADS for sclerotic/mixed lesions had sensitivities of 75% and 68%, specificities of 27% and 27%, and accuracies of 45% and 42% for readers 1 and 2, respectively. Inter-reader reliability was moderate to very good (κ = 0.744, overall; 0.565, lucent lesions; and 0.851, sclerotic/mixed lesions). CONCLUSION: Bone-RADS has a high sensitivity for evaluating malignancy in lucent bone lesions and good inter-reader reliability. However, it has poor specificity and accuracy for both lucent and sclerotic/mixed lesions. A possible explanation is that proposed algorithms heavily depend on clinical features such as pain and history of malignancy.

Fear of cancer recurrence in adolescent patients with malignant bone tumors: a cross-section survey.

BACKGROUND: Adolescent malignant-bone tumor patients' fear of cancer recurrence is a significant psychological issue, and exploring the influencing factors associated with fear of cancer recurrence in this population is important for developing effective interventions. This study is to investigate the current status and factors influencing fear of cancer recurrence (FCR) related to malignant bone-tumors in adolescent patients, providing evidence for future targeted mental health support and interventions. DESIGN: A cross-sectional survey. METHODS: In total, 269 adolescent malignant-bone tumor cases were treated at two hospitals in Zhejiang Province, China from January 2023 to December 2023. Patients completed a General Information Questionnaire, Fear of Progression Questionnaire-Short Form (FoP-Q-SF), Family Hardiness Index (FHI), and a Simple Coping Style Questionnaire (SCSQ). Univariate and multivariable logistic regressions analysis were used to assess fear of cancer recurrence. RESULTS: A total of 122 (45.4%) patients experienced FCR (FoP-Q-SF ≥ 34). Logistic regression analysis analyses showed that per capita-monthly family income, tumor stage, communication between the treating physician and the patient, patient's family relationships, family hardiness a positive coping score, and a negative coping score were the main factors influencing FCR in these patients (P < 0.05). CONCLUSIONS: FCR in malignant-bone tumor adolescent patients is profound. Healthcare professionals should develop targeted interventional strategies based on the identified factors, which affect these patients; helping patients increase family hardiness, helping patients to positively adapt, and avoid negative coping styles.

Treatment algorithm for metastatic malignancies in the lower extremities.

A high prevalence of proximal femoral metastases persists in patients with cancer, particularly regarding lower extremity fractures. This study offers a detailed analysis of clinical characteristics of patients undergoing surgical treatment for pathological or impending fractures, enhancing treatment strategies for metastatic malignancies. A total of thirty patients who underwent treatment of impending and pathological fractures at Kindai University Hospital (Osakasayama, Japan) were included. The retrospective study comprised parameters including age, sex, fracture site, type of primary malignancy, number of metastases, pre-fracture Eastern Cooperative Oncology Group performance status (ECOG-PS) score, adjuvant therapy, treatment modality, operative time, blood loss, postoperative complications, Musculoskeletal Tumor Society (MSTS) score, outcome and follow-up period. Post-treatment MSTS scores were compared in cases of impending and pathological fractures, and between intramedullary nailing and other surgical procedures. In addition, one-year postoperative survival rates were calculated. Furthermore, operative time, blood loss and survival rates were compared between impending and pathological fractures. The participants' median age was 70.5 years, with disease sites primarily in the subtrochanteric femur, trochanteric femur, femoral diaphysis, femoral neck and other locations. Pathologies included multiple myeloma and unknown primary, lung, breast, kidney, liver, gastric, esophageal and uterine cancers. The median ECOG-PS score pre-fracture was 2. Treatment approaches involved radiotherapy, chemotherapy and a combination of both. Surgical interventions included intramedullary nailing (16 cases), endoprosthesis (1 case), bipolar head replacement (3 cases) and compression hip screw (3 cases), among others. A negative correlation (R=-0.63) existed between MSTS and pre-fracture ECOG-PS scores. The operative time was significantly shorter in impending than in pathological fractures, with impending fractures showing significantly lower blood loss. The treatment algorithm for malignant bone tumors of the lower extremity provided in the present study was efficient, potentially optimizing treatment strategies for such cases, and contributing to improved patient care and outcomes in oncology and orthopedic surgery.

Assessing the influence of gastrocnemius reconstruction on stress distribution of femoral tumor rotating hinge knee prosthesis via finite element analysis.

Background: After femoral oncological knee arthroplasty, some patients suffer from rotating axis fracture, which significantly impacts the life span of the rotating hinge knee (RHK) prosthesis. This research aimed to analyze the biomechanical response of anatomical gastrocnemius reconstruction and assess whether it could reduce the risk of rotating axis breakage by finite element (FE) analysis. Methods: A femur-prosthesis-tibia FE model was established using the data from CT scans. The mechanical properties of the RHK implant were quantitatively compared before and after gastrocnemius reconstruction at 6 angles: 10°, 20°, 30°, 40°, 50°, and 60°. Results: Our results showed that gastrocnemius reconstruction effectively altered the stress distribution around the rotating axis, considerably relieving the stress in the fracture-prone region. In addition, the peak stress in the rotating axis, bending axis, prosthesis stem, and femoral condyles decreased variably. Conclusion: In distal femoral resection knee arthroplasty, the rebuilding of gastrocnemius substantially improved the stress distribution within the prosthesis, thereby having the potential to reduce the risk of prosthetic fracture and prolong the overall durability of the prosthesis.

Sacrococcygeal chordoma with spontaneous regression due to a large hemorrhagic component.

Chordoma is a malignant bone tumor originating from notochordal remnants, most commonly occurring at the sacrococcygeal junction. We present a case of a 70-year-old male with chronic pain in the lower lumbar spine. MRI performed elsewhere revealed a large tumor that involved S4, S5, and the coccyx with a presacral soft tissue component. The lesion was heterogeneously hyperintense on T2-weighted images with a thick hypointense rim anteriorly. On T1-weighted images, the lesion showed a native hyperintense signal centrally probably due to hemorrhage. Based on this MRI, the diagnosis of chordoma was suggested. A spontaneous marked reduction in size was observed on a 4-week interval MRI performed at our institution before biopsy. Due to spontaneous tumor shrinkage along with peripheral enhancement, a differential diagnosis of infection or bleeding in a retrorectal cyst was proposed. This case teaches us that chordomas may contain a large hemorrhagic component, which is hyperintense on T1-weighted images and shows peripheral rim enhancement. Spontaneous shrinkage of a tumor may occur due to the resolution of a hematoma within weeks. Biopsy is key to obtain the correct diagnosis. Understanding the typical and more rare features of chordomas is key for MSK radiologists as well as pathologists. Chordomas are typically slow-growing tumors, but radiologists should be aware that intratumoral hemorrhage can lead to rapid changes in tumor size, which may be mistaken for either regression or progression of tumor. This case highlights the importance of considering hemorrhagic events within chordomas in the differential diagnosis when observing size fluctuations on imaging.

Isolated skeletal Langerhans cell histiocytosis in adults: A case report.

INTRODUCTION AND IMPORTANCE: LCH in adults is rarely encountered, with the preference in children and axial skeleton as predilection site. Limited understanding of adult LCH causes frequent misdiagnosis, as our experience in an adult case of LCH threw off our differential diagnosis. CASE PRESENTATION: A 21-year-old male was referred to our hospital due to pain in his right shoulder. Plain radiograph and MRI showed a solitary well-marginated lytic lesion on the distal third of the clavicle. Together with a clear history and physical exam, the benign bone cyst was suspected and we performed an open biopsy simultaneously with curettage followed by internal fixation using a bone graft. Pathology and immunohistochemistry dismissed our suspicion and confirmed LCH as the main diagnosis. At six months post-surgery, no signs of recurrence were seen on the fixated site nor complained by the patient. DISCUSSION: Diagnosing LCH involves considering imaging appearances and patient demographics as initial clues. However, confirming the diagnosis requires a biopsy with proven CD1 expression. Currently, the majority of studies recommend confirming the diagnosis before initiating therapy. This precaution is necessary due to the unclear pathophysiology of LCH, which complicates the implementation of specific therapies. Based on benign features of skeletal lesions found from imaging, invasive treatment before biopsy confirmation still gave a satisfactory outcome despite not being in line with the current recommendation. CONCLUSION: Excisional biopsy and curettage in solitary LCH yield satisfactory outcomes. However, further studies are needed with larger sample sizes and interventional designs.

Pediatric Cranial Vault Pathology.

A wide variety of diagnoses can be approached with a common framework for diagnosis, extirpation, and reconstruction of pediatric cranial vault pathologies. Durability of reconstruction is critical for the range of pediatric patients from infancy to adolescence. Rigid reconstruction, preferably with autologous tissue when possible, promotes brain protection and satisfactory aesthetic outcome. Careful planning can allow for immediate definitive reconstruction of defects without need for further surgical intervention.

A radiograph-based deep learning model improves radiologists' performance for classification of histological types of primary bone tumors: A multicenter study.

PURPOSE: To develop a deep learning (DL) model for classifying histological types of primary bone tumors (PBTs) using radiographs and evaluate its clinical utility in assisting radiologists. METHODS: This retrospective study included 878 patients with pathologically confirmed PBTs from two centers (638, 77, 80, and 83 for the training, validation, internal test, and external test sets, respectively). We classified PBTs into five categories by histological types: chondrogenic tumors, osteogenic tumors, osteoclastic giant cell-rich tumors, other mesenchymal tumors of bone, or other histological types of PBTs. A DL model combining radiographs and clinical features based on the EfficientNet-B3 was developed for five-category classification. The area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity were calculated to evaluate model performance. The clinical utility of the model was evaluated in an observer study with four radiologists. RESULTS: The combined model achieved a macro average AUC of 0.904/0.873, with an accuracy of 67.5 %/68.7 %, a macro average sensitivity of 66.9 %/57.2 %, and a macro average specificity of 92.1 %/91.6 % on the internal/external test set, respectively. Model-assisted analysis improved accuracy, interpretation time, and confidence for junior (50.6 % vs. 72.3 %, 53.07[s] vs. 18.55[s] and 3.10 vs. 3.73 on a 5-point Likert scale [P < 0.05 for each], respectively) and senior radiologists (68.7 % vs. 75.3 %, 32.50[s] vs. 21.42[s] and 4.19 vs. 4.37 [P < 0.05 for each], respectively). CONCLUSION: The combined DL model effectively classified histological types of PBTs and assisted radiologists in achieving better classification results than their independent visual assessment.

Malignant Transformation in a Chondroblastoma-Does it Exist?

Chondroblastoma is currently described as a benign bone tumor, histopathologically characterized by its classical features including chondroblasts, pink cartilage, and a variable number of osteoclast-like giant cells with foci of dystrophic calcification. Although recurrent and metastasizing chondroblastomas are reported, a malignant chondroblastoma is exceedingly rare and somewhat a contentious entity. A 35-year-old male presented with a lump in his ankle of 15 years' duration. Imaging disclosed a lytic destructive lesion involving the lower ends of the tibia and fibula with a soft tissue component, indicative of atypical/"worrisome" features. Microscopic examination of the biopsy revealed distinct foci of chondroblastoma, transitioning to areas of high-grade sarcoma, including pleomorphic cells, increased mitoses, and prominent stromal hyalinization. Immunohistochemically, the entire tumor was positive for H3K36M, while DOG1 highlighted the areas of chondroblastoma. SATB2 highlighted the areas of high-grade sarcoma, sparing the areas of chondroblastoma. Additionally, the areas of a high-grade sarcoma showed multifocal desmin immunostaining. A diagnosis of a malignant transformation in a chondroblastoma was offered. The patient defaulted to further treatment and unfortunately died 8 months, post-diagnosis. The conceptual evolution of a malignant chondroblastoma with H3K36M immunostaining in the few reported tumors is described herewith.

FBXO22 is a potential therapeutic target for recurrent chondrosarcoma.

Chondrosarcoma (CHS) is a malignant bone tumor with insensitivity to both radiotherapy and chemotherapy, and a high recurrence rate. However, the latent mechanism of recurrent CHS (Re-CHS) remains elusive. Here, we discovered that FBXO22 was highly expressed in clinical samples of Re-CHS. FBXO22 played a significant role in various cancers. However, the role of FBXO22 in Re-CHS remained unclear. Our research demonstrated that suppressing FBXO22 abated the proliferation and migration of CHS cells and facilitated their apoptosis. In addition, suppressing FBXO22 raised the expression of PD-L1 in Re-CHS. All these findings provide new evidence for using FBXO22 and PD-L1 as combined targets to prevent and treat Re-CHS, which may prove to be a novel strategy for immunotherapy of CHS, especially Re-CHS.

Clinical Application of Unidirectional Porous Hydroxyapatite to Bone Tumor Surgery and Other Orthopedic Surgery.

Unidirectional porous hydroxyapatite (UDPHAp) was developed as a remarkable scaffold characterized by a distinct structure with unidirectional pores oriented in the horizontal direction and connected through interposes. We evaluated the radiographic changes, clinical outcomes, and complications following UDPHAp implantation for the treatment of bone tumors. Excellent bone formation within and around the implant was observed in all patients treated with intralesional resection and UDPHAp implantation for benign bone tumors. The absorption of UDPHAp and remodeling of the bone marrow space was observed in 45% of the patients at a mean of 17 months postoperatively and was significantly more common in younger patients. Preoperative cortical thinning was completely regenerated in 84% of patients at a mean of 10 months postoperatively. No complications related to the implanted UDPHAp were observed. In a pediatric patient with bone sarcoma, when the defect after fibular resection was filled with UDPHAp implants, radiography showed complete resorption of the implant and clear formation of cortex and marrow in the resected part of the fibula. The patient could walk well without crutches and participate in sports activities. UDPHAp is a useful bone graft substitute for the treatment of benign bone tumors, and the use of this material has a low complication rate. We also review and discuss the potential of UDPHAp as a bone graft substitute in the clinical setting of orthopedic surgery.

Spinal Cord Syndrome Due to Extramedullary Epithelioid Hemangioendothelioma of the Thoracic Spine: A Case Report and Literature Review.

We report a 48-year-old male patient with spinal epithelioid hemangioendothelioma in T3 and T4 who began with symptoms of paresthesia in the lower limbs and distal weakness of the right lower limb, back pain, increased limitation in walking, urinary incontinence, and constipation. A safe maximum resection was performed, finding residual disease during the PET/CT scan, so it was decided to treat with radiotherapy, and there was a good response to this treatment. A literature review of epithelioid hemangioendothelioma of the thoracic spine was done which showed a mean age of presentation of 41 years and a male-female ratio of 1:0.53. The main symptom was pain, which was present in 100% of the patients, and wide surgery was performed in 56.8% of the patients, intralesional surgery in 31.8%, and biopsy in 11.4%. A total of 46.6% of patients received radiation therapy, and only 6.6% received chemotherapy. The patients had an average follow-up of 38 months. We recommend that extension studies such as PET/CT scans be performed after surgical resection. This can serve as a follow-up with hemangioendothelioma epithelioma patients about metastatic disease or residual disease that will guide us in giving adjuvant treatments, such as radiotherapy or chemotherapy, for better control of the disease.