The role of grade in local recurrence and the disease-specific survival in chondrosarcomas

Aims

The purpose of this study was to describe the effect of histological grade on disease-specific survival in patients with chondrosarcoma.

Patients and Methods

A total of 343 patients with a chondrosarcoma were included. The histological grade was assessed on the initial biopsy and on the resection specimen. Where the histology showed a mixed grade, the highest grade was taken as the definitive grade. When only small focal areas showed higher grade, the final grade was considered as both.

Results

The concordance between the highest preoperative biopsy grading and the highest final grading of the resection specimen in total was only 43% (146/343). In 102 specimens (30%), a small number of cells or focal areas of higher grade were observed in contrast to the main histology. The disease-specific survival, stratified according to the predominant histological grade, showed greater variation than when stratified according to the highest grade seen in the resection specimen.

Conclusion

The diagnostic biopsy in chondrosarcoma is unreliable in assessing the definitive grade and the malignant potential of the tumour. When categorizing the grade of the resection specimen, the prognosis for local recurrence and disease-specific survival should be based on the highest grade seen, even when seen in only a few cells. Cite this article: Bone Joint J 2018;100-B:662-6.

Patient-derived xenograft models in musculoskeletal malignancies

Successful oncological drug development for bone and soft tissue sarcoma is grossly stagnating. A major obstacle in this process is the lack of appropriate animal models recapitulating the complexity and heterogeneity of musculoskeletal malignancies, resulting in poor efficiency in translating the findings of basic research to clinical applications. In recent years, patient-derived xenograft (PDX) models generated by directly engrafting patient-derived tumor fragments into immunocompromised mice have recaptured the attention of many researchers due to their properties of retaining the principle histopathology, biological behaviors, and molecular and genetic characteristics of the original tumor, showing promising future in both basic and clinical studies of bone and soft tissue sarcoma. Despite several limitations including low take rate and long take time in PDX generation, deficient immune system and heterologous tumor microenvironment of the host, PDXs offer a more advantageous platform for preclinical drug screening, biomarker identification and clinical therapeutic decision guiding. Here, we provide a timely review of the establishment and applications of PDX models for musculoskeletal malignancies and discuss current challenges and future directions of this approach.

Assessment of Chemotherapy Response Using FDG-PET in Pediatric Bone Tumors: A Single Institution Experience

Purpose

Response to neo-adjuvant chemotherapy is an important prognostic factor for osteosarcoma (OS) and the Ewing sarcoma family of tumors (ESFT). [F-18]-fluorodeoxy-D-glucose (FDG)-positron emission tomography (PET) is a non-invasive imaging modality that predicts histologic response to chemotherapy of various malignancies; however, limited data exist about the usefulness of FDG-PET in predicting the histologic response of pediatric bone tumors to chemotherapy. We analyzed the FDG-PET imaging characteristics of pediatric bone tumors and determined the association with response to chemotherapy.

Materials and Methods

Pediatric patients with OS (n=19) or ESFT (n=17) were evaluated for FDG-PET standard uptake values before (SUV1) and after (SUV2) chemotherapy. The relationship to the chemotherapy response was assessed by histopathology in surgically-excised tumors. A complete data set (SUV1, SUV2, and histologic response) was available in 23 patients.

Results

While the mean SUV1s were not different between patients with OSs and ESFTs (9.44 vs. 6.07, p=0.24), the SUV2s were greater in the patients with OSs than ESFTs (4.55 vs. 1.66, p=0.01). The ratios of SUV2-to-SUV1 (SUV2 : SUV1) were 0.65 and 0.35 for OS and ESFT, respectively (p=0.08). All of the patients with ESFTs and 47% of the patients with OS had a favorable histologic response to chemotherapy. The SUV_{2 : 1} [(SUV1-SUV2)/SUV1]≥0.5 and SUV2≤2.5 were related to favorable histologic responses to chemotherapy; the sensitivity and specificity of SUV_{2 : 1} at 0.5 and SUV2 at 2.5 were 93% and 88%, and 88% and 78%, respectively.

Conclusion

FDG-PET can be used as a non-invasive surrogate to predict response to chemotherapy in children with bone tumors.

Survival after second and subsequent recurrences in osteosarcoma: a retrospective multicenter analysis

PURPOSE

Osteosarcoma (OS) is the most common primary bone tumor. Despite complete surgical removal and intensive chemotherapeutic treatment, 30%-35% of patients with OS have local or systemic recurrence. Some patients survive multiple recurrences, but overall survival after OS recurrence is poor. This analysis aims to describe and identify factors influencing post-relapse survival (PRS) after a second OS relapse.

METHODS

This is a retrospective analysis of 60 patients with a second relapse of OS of the extremities in 2 Italian centers between 2003 and 2013.

RESULTS

Treatment for first and subsequent relapses was planned according to institutional guidelines. After complete surgical remission (CSR) following the first recurrence, patients experienced a second OS relapse with a median disease-free interval (DFI) of 6 months. Lung disease was prevalent: 44 patients (76%) had pulmonary metastases. Survival after the second relapse was 22% at 5 years. Lung disease only correlated with better survival at 5 years (33.6%) compared with other sites of recurrence (5%; p = 0.008). Patients with a single pulmonary lesion had a better 5-year second PRS (42%; p = 0.02). Patients who achieved a second CSR had a 5-year second PRS of 33.4%. Chemotherapy (p<0.001) benefited patients without a third CSR.

CONCLUSIONS

This analysis confirms the importance of an aggressive, repeated surgical approach. Lung metastases only, the number of lesions, DFI and CSR influenced survival. It also confirms the importance of chemotherapy in patients in whom surgical treatment is not feasible.

Ossifying fibroma of maxilla in a male child: Report of a case and review of the literature

Ossifying fibroma is a rare benign fibro-osseous neoplasm of the jaw characterized by substitution of normal bone by fibrous tissues and newly formed calcified products such as bone, cementum or both. It is a well-demarcated lesion that differentiates it from fibrous dysplasia. This case report describes a rare case of ossifying fibroma arising in the maxilla of an 11-year-old child treated with enucleation. The clinical, radiographical, surgical and histological findings are presented. Controversies regarding the terminology and classification along with the differential diagnosis are discussed and a review is provided of the literature on the subject.

Percutaneous guided biopsy for diagnosing suspected primary malignant bone tumors in pediatric patients: a safe, accurate, and cost-saving procedure

BACKGROUND

Percutaneous biopsy is the reference diagnostic procedure for adult musculoskeletal tumors. Its place in pediatrics is controversial and open biopsy remains recommended.

OBJECTIVE

To assess diagnostic performance and feasibility of percutaneous biopsy performed on children and young adults for suspected malignant bone tumors.

MATERIALS AND METHODS

We conducted a 5-year retrospective study including patients ≤21 years who underwent a bone biopsy for a suspected malignant bone tumor. We assessed diagnostic yield (percentage of analyzable biopsies), accuracy (percentage of accurate diagnoses among all analyzable biopsies) and efficacy (percentage of accurate diagnoses among all biopsies), costs, anesthetic requirements and sample availability for biomedical research. Patients diagnosed with an open biopsy were used to compare diagnostic performances, anesthetic requirements and costs.

RESULTS

We included 90 percutaneous and 27 open biopsies in 117 patients. For percutaneous biopsy, diagnostic yield was 95.5% (95% confidence interval [CI] 88.8-98.7%), accuracy was 96.2% (95% CI 86.8-99.5%) and efficacy was 89.3% (95% CI 78.1-96.0%). There was no statistical difference with open biopsy (Fisher exact test, P > 0.05). Mean costs were reduced with percutaneous biopsy: €1,937 (standard deviation [SD] €2,408) versus €6,362 (SD €5,033; Mann-Whitney, P < 0.0001). Thirty-two of the 48 (67%) patients included in clinical trials and diagnosed with percutaneous biopsy had suitable samples for ancillary analyses.

CONCLUSION

Percutaneous biopsy is a valid alternative to open biopsy for diagnosing pediatric and young adult primary malignant bone tumors.

Survival rate and neurological outcome after operation for advanced spinal metastasis (Tomita's classification > or = type 4)

PURPOSE

We investigated whether primary malignancy entities and the extent of tumor resection have an effect on the survival rate and neurological improvement in patients with spinal metastases that extend beyond the vertebral compartment (Tomita's classification > or = type 4).

MATERIALS AND METHODS

We retrospectively reviewed 87 patients with advanced spinal metastasis who underwent surgery. They were divided into groups 1 and 2 according to whether they responded to adjuvant therapy or not, respectively. They were subdivided according to the extent of tumor resection: group 1, gross total resection (G1GT); group 1, subtotal resection (G1ST); group 2, gross total resection (G2GT); and group 2, subtotal resection (G2ST). The origin of the tumor, survival rate, extent of resection, and neurological improvement were analyzed.

RESULTS

Group 1 had a better survival rate than group 2. The G1GT subgroup showed a better prognosis than the G1ST subgroup. In group 2, the extent of tumor resection (G2GT vs. G2ST) did not affect survival rate. In all subgroups, neurological status improved one month after surgery, however, the G2ST subgroup had worsened at the last follow-up. There was no local recurrence at the last follow-up in the G1GT subgroup. Four out of 13 patients in the G2GT subgroup showed a local recurrence of spinal tumors and progressive worsening of neurological status.

CONCLUSION

In patients with spinal metastases (Tomita's classification > or = type 4), individuals who underwent gross total resection of tumors that responded to adjuvant therapy showed a higher survival rate than those who underwent subtotal resection. For tumors not responding to adjuvant therapy, we suggest palliative surgical decompression.

Chondroblastoma in pelvis and extremities- a signle centre study of 177 cases

Introduction

Chondroblastoma is a rare benign bone tumour that usually occurs in children and young adults. They are cartilaginous tumours arising in the epiphysis or apophysis of a long bone. The tumour is classified as benign, although rare cases of pulmonary metastases have been reported. The aims of this study were to describe clinical, radiographic characteristics of chondroblastoma; to analyse the local recurrence rate and complications associated with surgery.

Material and methods

This retrospective study included 177 patients, who had been diagnosed with a chondroblastoma in extremity between 1990 and 2015.

Results

The most common site was proximal tibia 20%, followed by proximal humerus 19%, proximal femur 18%, distal femur 16% and foot 15%. One patient has died of the disease and one patient is alive after being operated for lung metastases. There was local recurrence in 25/177 (14%) patients. The median time to local recurrence was 10 months (range 3–158 months). The most common site for local recurrence was proximal tibia (22.2%). The proximal femur was the location in 32/178 (18%) of the cases. 18/32 (56%) were in the greater trochanter and 14/32 (44%) in the femoral head. The mean age was lower in tumours located in femoral head when compared to the greater trochanter; 19.5 years and 13.9 years respectively (p = =0.004). Tumours located in greater trochanter were all curetted without further complications. Local recurrence was seen more often in femoral head tumours, though without statistical significance; 3/14 (21%) and none, respectively (p = =0.073).

Conclusions

Chondroblastoma is a rare benign to intermediate grade bone tumour with a potential to metastasise. Femoral head chondroblastoma is rare, presenting 4.5% of all chondroblastoma cases. Around 50% of the chondroblastoma in femoral head. occur in patients with open growth plates.

Sclerosing epithelioid fibrosarcoma of bone: morphological, immunophenotypical, and molecular findings of 9 cases

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.

Mutation-driven epigenetic alterations as a defining hallmark of central cartilaginous tumours, giant cell tumour of bone and chondroblastoma

Recently, specific driver mutations were identified in chondroblastoma, giant cell tumour of bone and central cartilaginous tumours (specifically enchondroma and central chondrosarcoma), sharing the ability to induce genome-wide epigenetic alterations. In chondroblastoma and giant cell tumour of bone, the neoplastic mononuclear stromal-like cells frequently harbour specific point mutations in the genes encoding for histone H3.3 (H3F3A and H3F3B). The identification of these driver mutations has led to development of novel diagnostic tools to distinguish between chondroblastoma, giant cell tumour of bone and other giant cell containing tumours. From a biological perspective, these mutations induce several global and local alterations of the histone modification marks. Similar observations are made for central cartilaginous tumours, which frequently harbour specific point mutations in the metabolic enzymes IDH1 or IDH2. Besides an altered methylation pattern on histones, IDH mutations also induce a global DNA hypermethylation phenotype. In all of these tumour types, the mutation-driven epigenetic alterations lead to a highly altered transcriptome, resulting for instance in alterations in differentiation. These genomic alterations have diagnostic impact. Further research is needed to identify the genes and signalling pathways that are affected by the epigenetic alterations, which will hopefully lead to a better understanding of the biological mechanism underlying tumourigenesis.

Differentiating benign from malignant bone tumors using fluid-fluid level features on magnetic resonance imaging

Objective

To analyze different fluid-fluid level features between benign and malignant bone tumors on magnetic resonance imaging (MRI).

Materials and Methods

This study was approved by the hospital ethics committee. We retrospectively analyzed 47 patients diagnosed with benign (n = 29) or malignant (n = 18) bone tumors demonstrated by biopsy/surgical resection and who showed the intratumoral fluid-fluid level on pre-surgical MRI. The maximum length of the largest fluid-fluid level and the ratio of the maximum length of the largest fluid-fluid level to the maximum length of a bone tumor in the sagittal plane were investigated for use in distinguishing benign from malignant tumors using the Mann-Whitney U-test and a receiver operating characteristic (ROC) analysis. Fluid-fluid level was categorized by quantity (multiple vs. single fluid-fluid level) and by T1-weighted image signal pattern (high/low, low/high, and undifferentiated), and the findings were compared between the benign and malignant groups using the χ² test.

Results

The ratio of the maximum length of the largest fluid-fluid level to the maximum length of bone tumors in the sagittal plane that allowed statistically significant differentiation between benign and malignant bone tumors had an area under the ROC curve of 0.758 (95% confidence interval, 0.616-0.899). A cutoff value of 41.5% (higher value suggests a benign tumor) had sensitivity of 73% and specificity of 83%.

Conclusion

The ratio of the maximum length of the largest fluid-fluid level to the maximum length of a bone tumor in the sagittal plane may be useful to differentiate benign from malignant bone tumors.

Clinical differences between central and peripheral chondrosarcomas

AIMS

Chondrosarcoma is the second most common primary sarcoma of bone: conventional chondrosarcoma accounts for 85% of all cases. Conventional chondrosarcoma may be central or peripheral. Most studies group central and peripheral chondrosarcomas together, although there is growing evidence that their clinical behaviour and prognosis differ. The aims of this study were to analyze any differences in characteristics between central and peripheral chondrosarcomas and to investigate the incidence and role of different syndromes.

METHODS

Data from two international tertiary referral sarcoma centres between January 1995 and December 2018 were retrospectively reviewed. The study population consisted of 714 patients with surgically treated conventional chondrosarcoma of the pelvis and limbs.

RESULTS

In patients with Ollier's disease and Mafucci's syndrome, 12/20 (60%) and 2/5 (60%) of malignancies, respectively, were in the limbs, most frequently in the proximal humerus, proximal tibia, and in the hands and feet. In patients with hereditary multiple exostosis (HME), 20/29 (69.0%) of chondrosarcomas were in the pelvis and scapula, specifically in the ilium in 13/29 (44.8%) and the scapula in 3/29 (10.3%). In central chondrosarcoma, survival of patients with Ollier's disease and non-syndromic patients was the same (p = 0.805). In peripheral chondrosarcoma, survival among HME patients was similar (p = 0.676) in patients with tumours of the pelvis and limbs.

CONCLUSION

Both central and peripheral chondrosarcoma have specific characteristics. HME is frequently seen in patients with a peripheral chondrosarcoma, in whom tumours are commonly located in the ilium and scapula. The incidence of Ollier's disease is uncommon in patients with a central chondrosarcoma. Disease-specific survival is equal in different subtypes after adjustment for histological grade. The local recurrence-free survival is the same for different locations and subtypes after adjustment for surgical margin. Cite this article: Bone Joint J 2021;103-B(5):984-990.

Multifocal hemangioendothelioma of the lumbar spine and response to surgical resection and radiation

BACKGROUND CONTEXT

Epithelioid hemangioendothelioma rarely occurs in the lumbosacral spine, with very few case reports of spinal hemangioendothelioma in the literature. There is variability in aggressiveness of these lesions without established treatment guidelines.

PURPOSE

The aim was to present a case of epithelioid hemangioendothelioma in the lumbar spine, including magnetic resonance imaging (MRI) findings, which rapidly progressed over a 2-month period as regional multifocal lumbosacral spinal lesions with epidural extension causing severe spinal canal stenosis.

STUDY DESIGN/SETTING

This was a case report in a university hospital setting.

PATIENT SAMPLE

The sample included an otherwise healthy adult male with low back pain.

METHODS

Multimodality imaging was performed to help with diagnosis and management including computed tomography, MRI, and positron emission tomography (PET). The patient was treated by embolization, L5 corpectomy and L4-S1 stabilization, and radiation therapy. The diagnosis was confirmed by tissue biopsy.

RESULTS

The patient initially presented with severe back and leg pain after a vertebroplasty for an L5 compression fracture at an outside hospital where biopsy was negative for malignancy. Magnetic resonance imaging showed diffuse abnormality of L5 with several smaller lesions in the sacrum. Due to progressive pain 2 weeks after the vertebroplasty, the patient underwent an L5 laminectomy, L4-S1 instrumented posterior fusion, and attempted partial corpectomy for stenosis. At this surgery, the L5 corpectomy was aborted owing to profound bleeding. Pathology was again negative for malignancy. Presumed to be an atypical hemangioma, the lesion was embolized before repeat surgery where the thecal sac was decompressed by partial L5 corpectomy. Biopsy at this time revealed a vascular neoplasm, with hemangioendothelioma not excluded. Approximately 2 months after the stabilization procedure, the patient had increasing pain and bilateral lower extremity weakness. Magnetic resonance imaging was performed and demonstrated marked local progression of disease with new multifocal lesions involving L4 through S2 vertebrae and new severe spinal canal stenosis. These lesions were subsequently treated with localized radiation therapy. Magnetic resonance imaging 2 months after radiation therapy showed significant regression of the epidural tumor although a new metastatic lesion was discovered at T6 vertebra.

CONCLUSIONS

Spinal hemangioendothelioma is a rare disease and can present in variable forms, including as a multifocal regional process--which may be mistaken for infection. Additionally, there are no standard treatment protocols for this entity. We present the extensive imaging and treatment of a single case of rapidly progressive lumbar epithelioid hemangioendothelioma, which to our knowledge has not been described with this multifocal appearance in the lumbar spine.

Monitoring Response to Neoadjuvant Chemotherapy of Primary Osteosarcoma Using Diffusion Kurtosis Magnetic Resonance Imaging: Initial Findings

Objective

To determine whether diffusion kurtosis imaging (DKI) is effective in monitoring tumor response to neoadjuvant chemotherapy in patients with osteosarcoma.

Materials and Methods

Twenty-nine osteosarcoma patients (20 men and 9 women; mean age, 17.6 ± 7.8 years) who had undergone magnetic resonance imaging (MRI) and DKI before and after neoadjuvant chemotherapy were included. Tumor volume, apparent diffusion coefficient (ADC), mean diffusivity (MD), mean kurtosis (MK), and change ratio (ΔX) between pre- and post-treatment were calculated. Based on histologic response, the patients were divided into those with good response (≥ 90% necrosis, n = 12) and those with poor response (< 90% necrosis, n = 17). Several MRI parameters between the groups were compared using Student's t test. The correlation between image indexes and tumor necrosis was determined using Pearson's correlation, and diagnostic performance was compared using receiver operating characteristic curves.

Results

In good responders, MD_post, ADC_post, and MK_post values were significantly higher than in poor responders (p < 0.001, p < 0.001, and p = 0.042, respectively). The ΔMD and ΔADC were also significantly higher in good responders than in poor responders (p < 0.001 and p = 0.01, respectively). However, no significant difference was observed in ΔMK (p = 0.092). MD_post and ΔMD showed high correlations with tumor necrosis rate (r = 0.669 and r = 0.622, respectively), and MD_post had higher diagnostic performance than ADC_post (p = 0.037) and MK_post (p = 0.011). Similarly, ΔMD also showed higher diagnostic performance than ΔADC (p = 0.033) and ΔMK (p = 0.037).

Conclusion

MD is a promising biomarker for monitoring tumor response to preoperative chemotherapy in patients with osteosarcoma.

Regression of a solitary osteochondroma of the distal humerus in a toddler following trauma

Osteochondromas are bone exostoses, with the vast majority extending from the metaphyseal region of long bones and are capped by cartilage. A review of the current literature reveals spontaneous regression of osteochondromas is a rarely documented event, with all but two of these recorded events resolving before skeletal maturity and within 6 years of identification. We present a case of trauma-induced resolution of a solitary osteochondroma after less than 3 months in a 15-month-old male, with a review of current literature.

Diffusion-weighted imaging in differentiating mid-course responders to chemotherapy for long-bone osteosarcoma compared to the histologic response: an update

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.

Primary perivascular epithelioid cell tumor (PEComa) in bone: A review of the literature and a case arising in the humerus with multiple metastases

•

First case PEComa primary arising in humerus was described.

•

Histology is the basic to determine malignancy of PEComa.

•

TFE3 gene investigation is the key of therapy selection.

•

mTOR inhibitor is believed to be effective for patients without TFE3 rearrangement.

•

More study is needed to understand the role of molecular test and imaging in PEComa.

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.

Primary diffuse large B-cell lymphoma associated with chronic osteomyelitis of the knee

Diffuse large B-cell lymphoma (DLBCL) associated with chronic inflammation is a recently adopted category of DLBCL, which describes an aggressive B-cell lymphoma raised in the setting of non-immune chronic inflammation. Primary presentation of this subtype of DLBCL in bone is extremely rare. Here, we present the case of a 27 year old woman with DLBCL of the right distal femur, identified after a three-year history of chronic osteomyelitis. In this report, we describe the clinical and histopathologic features of this unusual presentation of DLBCL and discuss aspects relevant to diagnosis and treatment of this entity.

Chondrosarcoma of the para-acetabulum: correlation of imaging features with histopathological grade

OBJECTIVE

To evaluate the computed tomography (CT) and magnetic resonance (MR) imaging features of para-acetabular chondrosarcoma (CS) and assess the difference between low-grade CS (LGCS) and high-grade CS (HGCS).

MATERIALS AND METHODS

Thirty-one patients with histopathologically confirmed central para-acetabular CSs (6 LGCS and 25 HGCS) were retrospectively reviewed. Image features were evaluated for the following: cortical destruction, tumor border and pattern, calcification mode, soft-tissue mass, density/signal intensity, peritumoral edema, acetabular (cartilage) destruction, diffuse signal changes in acetabulum, mass inside hip joint, femoral head involvement, enhancement manifestations and the maximum length of the tumor. These image features between LGCS and HGCS were also assessed.

RESULTS

The most common CT and/or MR findings included cortical destruction, punctate, ring-and-arc and linear calcification, soft-tissue mass, lobulated border, high signal intensity with low signal septa on T2-weighted image, peritumoral edema, hip joint infiltration, peripheral and septal enhancement on post-enhanced MR image. Statistical analysis showed that the image features, such as cortical destruction, soft-tissue mass, hip joint infiltration and tumor size were significantly different between LGCS and HGCS (p < 0.05).

CONCLUSION

The characteristic radiological features of para-acetabular CSs are osteolytic lesions with cortical destruction, soft-tissue mass, lobulated border, calcification, and high signal intensity with low signal septa on T2-weighted MR image, peripheral and septal enhancement on post-enhanced MR image. Cortical destruction, soft-tissue mass, hip joint infiltration and tumor size can differentiate HGCS from LGCS.

MRI appearances of atypical cartilaginous tumour/grade I chondrosarcoma after treatment by curettage, phenolisation and allografting: recommendations for follow-up

AIMS

The purpose of this retrospective study was to differentiate between the MRI features of normal post-operative change and those of residual or recurrent disease after intralesional treatment of an atypical cartilage tumour (ACT)/grade I chondrosarcoma.

PATIENTS AND METHODS

We reviewed the case notes, radiology and histology of 75 patients, who had been treated for an ACT/grade I chondrosarcoma by curettage, phenolisation and bone allografting between 1994 and 2005. The first post-operative Gd-enhanced MRI scan was carried out within one year of surgery. Patients had a minimum of two scans and a mean follow-up of 72 months (13 to 169). Further surgery was undertaken in cases of suspected recurrence.

RESULTS

In 14 patients (18.6%) a second procedure was undertaken after a mean period of 59 months (8 to 114). Radio frequency ablation (RFA) was used in lesions of < 10 mm and curettage, phenolisation and bone grafting for those ≥ 10 mm. Only six of these (8% of total) had a histologically-proven recurrence. No increase in tumour grade was seen at time of recurrence.

CONCLUSION

Based on this study, we have been able to classify the post-operative MRI appearances into four groups. These groups differ in follow-up, and have a different risk of recurrence of the lesion. Follow-up and treatment vary for the patients in each group. We present a flow diagram for the appropriate and safe follow-up for this specific group of patients. Cite this article: Bone Joint J 2016;98-B:1674-81.

3D-printed hemipelvic prosthesis combined with a dual mobility bearing in patients with primary malignant neoplasm involving the acetabulum: clinical outcomes and finite element analysis

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.

Scapular osteochondroma with winging: A case report

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Osteochondroma is a benign cartilaginous tumour that rarely affects the scapula.

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We present a rare case of osteochondroma with winging of scapula, present in his fourth decade of life.

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This symptomatic scapular osteochondroma exhibited positive radiological findings.

•

The patient was treated surgically and recovered fully, with no recurrence.

•

This report increases awareness of unusual osteochondroma sites and features.

Introduction

Osteochondroma, a type of cartilaginous tumour, is the most common benign tumour affecting the bone. These tumours usually arise around the knee, proximal humerus, and pelvis, but very rarely occur at the scapula. Osteochondromas are usually asymptomatic and uncomplicated, but must be treated by surgical resection.

Presentation of case

In this report, we present a rare case of a symptomatic scapular osteochondroma associated with scapular winging in a 30-year-old man. This tumour exhibited positive radiological findings and was treated surgically, leading to a complete resolution of the patient's symptoms with no history of recurrence.

Discussion

This case was unique because although the patient presented in his fourth decade of life, he had not noticed any signs indicative of lesional growth during adolescence and the maturation process. Additionally, this case was symptomatic and involved an unusual site.

Conclusion

By reporting this rare case of a ventral-side scapular osteochondroma that presented with scapular winging, we aim to increase the awareness of the unusual manifestations of osteochondroma, particularly atypical sites, signs, and symptoms. Furthermore, we have described the surgical treatment of this case in detail to assist other surgeons who face similar cases.

Outcomes from a mechanistic biomarker multi-arm and randomised study of liposomal MTP-PE (Mifamurtide) in metastatic and/or recurrent osteosarcoma (EuroSarc-Memos trial)

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.

Bone Metastases in Follicular Carcinoma of Thyroid

Though the association between follicular carcinoma and bone metastasis is well established, the site-wise distribution is not known. One hundred seventy-three patients of follicular carcinoma presenting between 2003 and 2011 were selected from 1093 patients of follicular lesions presenting at a single institution. Of these, 59 (34%) with bone metastasis were included in the study. Fifty of the 59 patients (84.7%) had metastasis at presentation, while 9 developed bone metastasis during follow-up. Sixty-one percent had solitary metastasis, 15 (25.4%) had multiple bone involvement, while 8 patients (13.6%) had synchronous lung metastasis. Overall, the spine was the commonest site of bone metastases, seen in 20 patients (33.9%), followed by the pelvis, skull, long bones and sternum. Bone metastasis is a known phenomenon in follicular carcinoma. The spine is the commonest site followed by the pelvis.

Chondroblastic osteosarcoma of the left zygomatic bone: Rare case report and review of the literature

Chondroblastic osteosarcoma (COS), a subgroup of intramedullary osteosarcoma (OS), is the most common osteosarcoma that occurs in adolescents and early adulthood. The COS has similar clinical and radiological features to those of conventional OS. We present a case of 20-year-old male patient with the chief complaint of pain and swelling in the left zygomatic region. The computed tomography (CT) and three-dimensional (3D) CT face showed erosion, calcific foci, sunray type of spicules suggestive of OS. On fine-needle aspiration cytology (FNAC) examination, initial diagnosis was malignant chondroid lesion, with differential diagnosis of mesenchymal chrondrosarcoma, COS on incisional biopsy and finally COS on excisional biopsy. The patient underwent radical resection of left zygomatic arch, followed by chemotherapy. Although clinically unsuspected in this unusual site, histopathology along with immunohistochemistry (IHC) results confirmed the COS. Because zygomatic location of COS is very rare, this report aimed to discuss clinical, radiographic, histopathologic, IHC findings and diagnostic pitfalls of COS in light of the literature.