Tumors Of Long Bones Research Articles

Combined Cortico-cancellous and cancellous fresh paternal allograft in defect post resection of benign bone tumors of long bones in children, review of literatures with two cases study

We study the use of paternal fresh allograft in pediatric massive bony loss (post benign bone tumor resection) with a graft type of combined Cortico-cancellous and cancellous bone, with a good result of rapid and complete union with no recurrence with in 2years of follow up, with no any sign of local or systemic rejection. Study of 2 patients, one of an osteoblastoma in female of 9 years old in shaft femur and the second case was an aneurysmal bone cyst (ABC) in male of 11 years old in distal third of fibula where in both do enbloc resection for a big bony lesions in such young age group, the defect was 8cm in the female and 9 cm in male case. We reconstruct these defects by the fresh non-frozen paternal allograft which still not widely used method and we add the use of Combined Cortico-cancellous and cancellous bone graft of iliac crest area which was not used or mentioned before in literatures and we do internal fixation in both and we wash the graft 2 times pre and post application in the gap with a normal saline for each case, follow up by monthly x-ray films till healing. Was conclusive and more than expected regarding healing rate and union which was 6month in female case and 5 month in male and no complication in such big bony graft mass. In Followed up of 2 years no recurrance was seen and both donors and recipients without any disability nor morbidity.

Primary Osteosarcoma of the Maxillary Sinus: An Exceptional Presentation

Osteosarcoma is a common primary malignant tumor of long bones in which mesenchymal cells produce osteoid, affecting mainly young adults. Head and neck localization is rare, moreover at the level of the maxillary sinus. The certainty diagnosis is based on the clinical CT and histopathological findings. This histological type is associated with a low risk of metastasis. Early diagnosis and wide surgical resection of the tumor are the most important determinant factors of prognosis. In this article, we report a case where radiotherapy was used.

CT radiomics-based machine learning classification of atypical cartilaginous tumours and appendicular chondrosarcomas.

BackgroundClinical management ranges from surveillance or curettage to wide resection for atypical to higher-grade cartilaginous tumours, respectively. Our aim was to investigate the performance of computed tomography (CT) radiomics-based machine learning for classification of atypical cartilaginous tumours and higher-grade chondrosarcomas of long bones.MethodsOne-hundred-twenty patients with histology-proven lesions were retrospectively included. The training cohort consisted of 84 CT scans from centre 1 (n=55 G1 or atypical cartilaginous tumours; n=29 G2-G4 chondrosarcomas). The external test cohort consisted of the CT component of 36 positron emission tomography-CT scans from centre 2 (n=16 G1 or atypical cartilaginous tumours; n=20 G2-G4 chondrosarcomas). Bidimensional segmentation was performed on preoperative CT. Radiomic features were extracted. After dimensionality reduction and class balancing in centre 1, the performance of a machine-learning classifier (LogitBoost) was assessed on the training cohort using 10-fold cross-validation and on the external test cohort. In centre 2, its performance was compared with preoperative biopsy and an experienced radiologist using McNemar's test.FindingsThe classifier had 81% (AUC=0.89) and 75% (AUC=0.78) accuracy in identifying the lesions in the training and external test cohorts, respectively. Specifically, its accuracy in classifying atypical cartilaginous tumours and higher-grade chondrosarcomas was 84% and 78% in the training cohort, and 81% and 70% in the external test cohort, respectively. Preoperative biopsy had 64% (AUC=0.66) accuracy (p=0.29). The radiologist had 81% accuracy (p=0.75).InterpretationMachine learning showed good accuracy in classifying atypical and higher-grade cartilaginous tumours of long bones based on preoperative CT radiomic features.FundingESSR Young Researchers Grant.

Surgical treatment of bone tumors using segmental bone allografts

The aim of the study is to improve the method of surgical treatment for patients with tumors of long bones with the use of segmental bone allograft. Material and method. The authors have improved the method of surgical treatment of patients with tumor bone lesions using segmental allografts. Step-cut osteotomy was performed to achieve the best contact between the allograft and the recipient bone, fixation was performed with intramedullar interlocking nail without the use of bone cement, and primary bone autoplasty was done to achieve better reparation. The method was clinically tested and the results of its application were studied (radiologically, morphologically). A morphological study of the contact zone between the allograft and the recipient's bone was conducted. Results. The effectiveness of the developed method was proved. As a follow-up result among patients who underwent surgical treatment according to the developed method, the following complications were noted: ischemic necrosis of soft tissues (due to intraoperative ligation of an artery which was surrounded by a tumor) – 1 case; tumor recurrence resulting in a limb amputation – 1 patient. During the macroscopic study of a removed fragment (after amputation), the fusion between allograft and recipient bone was observed. As a result of histological and X-ray examination, bone regeneration was seen in the area of contact between the allograft and the recipient bone. The histological examination also was used to clearly visualize the removed fragment of the affected tibia, in particular the contact zone between the allograft and the recipient bone, and the bone implant material, on the outer surface and internal parts of which, the formation of new bone tissue in the form of layering of the bone trabeculae was seen. Thus, the bone tissue was formed on the surface of allogeneic bone material and sprouted into its internal parts, forming a stiff bone – implant contact. Conclusions. Using the technique of bioreconstruction of the long bone defects allows the bone tissue of the affected limb to be preserved as much as possible, to restore the surrounding soft tissues and avoid infectious and allergic reactions in comparison with modular endoprosthetics. Fixation of the allograft and the recipient bone using step-cut osteotomy with the additional insertion of an interlocking intramedullar nail allows getting a stable «construction» and maximizing the contact zone of the bone tissue (the allograft and the recipient bone).

The results of surgical treatment of giant cell tumor of long bones

The standard treatment option for Giant cell tumor (GCT) is surgery. The radical resection followed by reconstruction is associated with definite clinical problem: high rate of complications, reducing of limb function. Tumor excohleation allows to preserve the joint, but has a high rate of local recurrence. Objective: in retrospective study to analyze the advantages and disadvantages of intralesions and wide radical resection based on results of treatment in patients with Giant cell tumor. Methods: we performed a retrospective analysis of treatment results of 142 patients with long bones Giant cell tumor in the period from 1977 to 2012 years. Tumor excohleation (intralesional resection, IR) with grafting the defect with bone or biodegradable materials was performed in 70 cases, wide resections (WR) with defect reconstructions — in 72 patients. Results: in the group of patients who underwent IR the local relapses were revealed in 35.7 % of cases, which is seven times higher than in WR group. Functional result according to MSTS scale in patients after IR was 92.5 %, after WR — 78.8 % (p = 0.02). Such clinical factors as IR, localization of tumor in the distal radius, age under 25 years is strongly associated with appearence of local recurrence. For patients after IR PFS was 71.0 %, after WR — 95.8 % (p = 0.001). Conclusions: the optimal surgical method in patients with Giant cell tumor of long bones is IR due to good functional results. However, local relapse rate in this group remains high — 35.7 % versus 4.5 % in group after WR (p < 0.05). One of the way of its reducing is application of new therapeutic agents e. g. denosumab, the effectiveness of which can be assessed in prospective trials.

A Case Report of Giant Cell Tumor of Proximal Fibula in Children

Giant cell tumour (GCT) is histopathologically benign tumor of long bone particularly in distal femur and the proximal tibia. It commonly occurs in adults of age 20-40 years but rare in children. GCT is considered to be locally aggressive tumor and tendency of recurrence is higher even after surgery. The clinical features are nonspecific, the principle symptoms are pain, swelling and limiting adjacent joint movements. Diagnosis is based on the radiographic appearance and histopathological findings .In our case X-ray showed ill defined lytic lesion on proximal fibula with cortical thinning and MRI finding revealed expansile lyticlesion in meta-epiphysis of right fibula 16×16×28mm adjacent to growth plate with fluid level. The sclerotic rim appears hypo intense on T1 & hyper intense on T2. Core needle biopsy showed giant cell tumor on proximal fibula. Considering the risk of recurrence wide local excision was done. Management of GCT of proximal fibula in young patient is critical for preventing recurrence and enhancing functional outcomes by saving adjacent anatomical structure. No evidence of local recurrence and metastasis was found in 24 months of follow up.

Radiofrequency ablation of atypical cartilaginous tumors in long bones: a retrospective study

Purpose: To determine the size of the ablation zone after radiofrequency ablation (RFA) of atypical cartilaginous bone tumors (ACT) using temperature-controlled 20 and 30 mm RFA straight non-cooled electrodes.Materials and methods: Sixteen patients with ACT in their long bones, who had undergone a single-session single-application CT-guided temperature-controlled RFA, were included retrospectively in the study. Tumors with a diameter of 10–25 mm were treated with 20 mm electrodes (n = 10), and tumors of 25–35 mm, with 30 mm electrodes (n = 6). The ablated zone was measured after three months on MRI images.Results: All the tumors were within the ablated zone on the 3-month follow-up MRI scan. The mean ablation time with the electrode, at a target temperature of 90 °C, was 7.6 minutes (range 6–10). The median of the largest ablation diameters, on applying the 20 and 30 mm electrodes, were 42 mm (IQR 8.5, range 30–51 mm) and 44.5 mm (IQR 4.5, range 42–63 mm), respectively.Conclusions: All the retrospectively viewed tumors in the long bones of ACT patients treated with RFA were completely ablated. The ablation zone diameters in the bones were larger than expected, when compared to other tissues, such as the liver.

Early Diagnosis: A Seeming Misfortune for Osteosarcoma of Mandible-Rare Case Report.

Osteosarcoma is a mesenchymal malignant tumour of long bones; it is the second most common malignancy of bone after multiple myeloma but it rarely affects jaw, accounting only for 4-8% of all osteosarcomas (Baumhoer et al. in Oral Oncol 50(2):147-153, 2014). The rare occurrence of tumour makes it challenging to diagnose either by radiographic or histopathologic examination. Here we presented a rare case of chondroblastic variant of osteosarcoma of body of mandible in a 54year old female.

A Rare, yet Aggressive, Intra-Abdominal Malignancy: Ewing Sarcoma of the Pancreas

Introduction: Ewing sarcoma (ES) is a malignant bone tumor of long-bones, which typically occurs in children. Extraskeletal Ewing sarcoma (EES) is a poorly differentiated soft tissue sarcoma within morphologic category of ‘small-round-cell’ tumors and accounts for less than 1% of soft tissue sarcomas. Only 24 cases have been reported in the literature. Herein, we present an interesting case of EES of pancreas. Case Description: 34-year-old male presented to clinic secondary to insidious onset, generalized abdominal pain for past 1-month. Physical exam revealed non-tender, moderately distended abdomen with a palpable mass above the umbilicus. Initial lab workup showed mild elevation of AST 91 (0-50 U/L) and alkaline-phosphatase 337 (38-126 U/L). CT abdomen showed lobulated heterogeneous mass with necrotic transformation in body and tail of pancreas, with multiple liver lesions. Resultantly, a working diagnosis of adenocarcinoma of pancreas with metastasis to liver was made. A CT-guided biopsy of pancreatic and hepatic mass showed small, blue, round cells with scant cytoplasm. Hence, the previous diagnosis of pancreatic adenocarcinoma was disregarded, and other differential diagnoses including EES, neuroblastoma, non-Hodgkin's lymphoma vs desmoplastic small blue round cell tumor were considered. Further testing with immunohistochemistry confirmed the diagnosis of EES. Subsequently, patient was started on chemotherapy with doxorubicin, cyclophosphamide and vincristine. After one round of chemotherapy, patient developed neutropenic fever and died after 1-month from a complicated hospital course. Discussion: This case highlights an extremely rare type of soft tissue sarcoma (EES) at an unusual location. The diagnosis of ESS is confirmed by immunohistochemistry as imaging modalities often remain nonspecific. Histologically, ES and EES are described as small, blue, round cells with hyperchromatic nuclei and scant cytoplasm, with molecular expression of MIC2, CD99 and antibody against FLI1 centered in nucleus. Though 85% of the ES cases are associated with chromosomal translocation t(11;22) and q(24;12), it remains non-specific. EES is an aggressive and malignant tumor with a 5-year survival rate of around 50%. Surgical excision, plus chemotherapy and radiotherapy is the main modality of treatment. Though EES is rare, physicians should be acquainted with and consider it in the differential diagnosis, as early recognition and intervention is very critical.1397_A.tif Figure 1: Necrotic mass (14.8cm x 5.6cm x 6.7cm) again visualized in the pancreas along with multiple hypo-attenuated liver lesions.1397_B.tif Figure 2: Small, blue, round cells with high NC ratio, dark chromatin pattern with scant cytoplasm. Tumor cells positive for vimentin; negative for CD45, CD117, chromogranin, synaptophysin, pan cytokeratin, smooth muscle actin, desmin, HMB-45, S-100 and CD138. Pattern is highly consistent with high grade soft tissue sarcoma- EES.

Ошибки и осложнения при лечении больных с первичными опухолями длинных трубчатых костей нижних конечностей методом чрескостного остеосинтеза по Илизарову

Introduction The Ilizarov method of non-free bone plasty has been widely used for management of lower limb long bones after resection of primary tumors. Analysis of errors and complications by using this method is a demanded and relevant task. Purpose We retrospectively studied the errors and complications by using the method of Ilizarov non-free bone toplasty in patients with primary neoplasms in lower limb long bones. Material and methods Rehabilitation of 133 patients with primary tumors of lower limb long bones was analyzed. All of them were treated with the Ilizarov method of compression-distraction osteosynthesis for bridging post-resection defects. Results Our retrospective study revealed organizational, tactical, technical errors and complications, which we observed during clinical and rehabilitation stages. Conclusion Systematization of errors and associated complications allowed us to develop recommendations for their prevention and treatment.

Outcomes and Treatment of Malignant Tumors of Long Bones

Abstract Introduction. With the advances in chemotherapy, the life expectancy of patients with malignant tumors of bones begins to rise and creates the opportunity for a more conservative treatment of such cases. The main complications after using reconstruction with bone graft are represented by mechanical failure, due to the lack of strong fixation, or biological failure of graft integration. Infection is another complication, patients being usually immunosuppressed. The aim of this study was to investigate a retrospective single center experience of surgically treated malignant bone tumors of long bones, respectively oncological, surgical, and functional outcome differences after biological reconstruction. Materials and methods. Between 2007 and 2017, we conducted a retrospective study, with patients from Elias Orthopaedic Department. 70 patients with malignant tumors were treated. Only in 20 cases, resection-reconstruction was possible. Results. Survival rate at 8-year follow up was 35%. Mechanical failure rate was 20%, graft resorption rate was 25%, and infection rate was 15%. Discussion. Primary malignant tumors of bones are very rare, less than 1% of cancer cases, and yet there is no strict rule for treating these patients in specialized centers. Because of the small sample of patients, the heterogeneity of reconstruction methods and multiple types of grafts, this study also had some limitations. The mechanical or biological complication rate is higher in resectionreconstruction cases. Non-unions, fractures and infections are the most common complications.

Outcomes after extensive manual curettage and limited burring for atypical cartilaginous tumour of long bone.

Adjuvant treatment after intralesional curettage for atypical cartilaginous tumours (ACTs) of long bones is widely accepted for extending surgical margins. However, evaluating the isolated effect of adjuvant treatment is difficult, and it is unclear whether not using such adjuvants provides poor oncological outcomes. Hence, we analyzed whether intralesional curettage without cryosurgery or chemical adjuvants provides poor oncological outcomes in patients with an ACT. A total of 24 patients (nine men, 15 women) (mean age 45 years; 18 to 62) were treated for ACTs of long bones and followed up for a median of 66 months (interquartile range 50 to 84). All patients were treated with extensive manual curettage and limited burring. Bone cement and grafts were used to fill bone defects in 16 and eight patients, respectively. No chemical adjuvants or cryosurgery were used. No local recurrence was detectable on plain radiographs and MRI or CT images. At the last follow-up, there were no distant metastases or disease-specific deaths. No procedure-related complications or postoperative fractures developed. Intralesional curettage without cryosurgery or chemical adjuvants may provide excellent oncological outcomes for patients with ACTs of long bones, without the risk of complications related to adjuvant use. Our investigation suggests thorough curettage alone is a reasonable treatment option for ACT. However, we acknowledge the limited size of our investigation warrants a multicentre collaborative study to confirm our findings. Cite this article: Bone Joint J 2018;100-B:256-61.

Complications of Allograft Reconstruction following Wide Resection of Malignant Bone Tumors in Long Bones

Complications of Allograft Reconstruction following Wide Resection of Malignant Bone Tumors in Long Bones

Хирургическое лечение пациентов с опухолями длинных трубчатых костей верхних конечностей с использованием индивидуальных имплантатов из костнозамещающего материала, созданных по технологиям 3D-печати

Purpose To evaluate outcomes of surgical treatment of patients with tumors of long bones of upper limbs using a single-stage repair of bone defects with tailored bone substitute implants manufactured with 3D printing technique. Materials and methods Clinical and radiological assessment of 22 patients with tumors of long bones of upper limbs was produced after surgical treatment that included removal of neoplasm and one-stage bone plasty using a tailored implant manufactured with three-dimensional printing (Patent RU 2598769). Bone cement and Recost bone substitute (Patent RU 2518753) were used to produce an implant. All patients were evaluated preoperatively and at 12-month follow-up using the 36-item Short Form Health Survey (SF-36), Musculoskeletal Tumor Society (MSTS) Rating Scale and visual analogue scale (VAS). Results Postoperatively, all patients showed pain reduction and improved function of the upper limb. No radiographic evidence of implant migration was observed throughout the followup. Evaluation of benign patients at one year after surgical intervention showed average 71.4 ± 6.6 of SF-36, 2.5 ± 1.5 of VAS, and 65.1 ± 8.3 % of MSTS scoring system; malignant cases demonstrated average figures of SF-36 39.2 ± 4.3, VAS 4.8 ± 1.4, and 41.8 ± 5.2 % at MSTS rating scale. Conclusion Surgical treatment of patients with tumors of the humerus, ulna and radius using one-stage plasty of bone defects with tailored 3D-printed bone substitute implants has shown to be an efficient method in improving an affected upper limb function and patient’s quality of life. The use of 3D printing to manufacture implants allows for precise and single-stage repair of bone defects of any shape, size and complexity with the technique making surgery easier to perform.

Juvenile Psammomatoid Ossifying Fibroma (JPOF) of Proximal Radius: A Rare Entity.

Background:Juvenile psammomatoid ossifying fibroma (JPOF) is a rare fibro-osseous lesion that usually occurs in the facial bones. The pathognomonic histopathologic feature is the presence of spherical ossicles, which are similar to psammoma bodies. It is considered to be a unique lesion because of its reported tendency to occur in children and adolescents and its tendency for locally aggressive growth. Because this lesion is aggressive in nature with high recurrence rate, early detection and complete surgical excision are essential.Case Report:Herein, we present a case of 11 year old girl, who presented to our clinic with history of gradual onset pain around right elbow associated with limitation of right forearm rotation for 3 months. After getting informed consent, we performed needle biopsy and histopathologically it was diagnosed as Psammomatoid type juvenile ossifying fibroma (JPOF) of proximal radius. We performed extensive debridement, curettage of entire cystic lesion involving the proximal radius and filled the cavity with allograft bone granules and intramedullary titanium elastic nail through fibular strut graft, bridging the cystic lesion.Conclusion:As far as our knowledge there is no reported case of psammomatoid type of juvenile ossifying fibroma of proximal radius. We believe that such tumors in long bones are aggressive and have tendency for recurrence. Definitive diagnosis is utmost important for proper planning, surgical excision and reconstruction of long bones and need regular follow up to look for any recurrence or malignant transformation.

Giant-cell tumour of proximal radius in a 50-year-old female with wrist drop: a rare case report

Giant-cell tumour is a locally aggressive tumour of long bones of epiphyseal region commonly occurring in adults aged 20–40 years. Most common location is distal femur, proximal tibia, and distal radius. Different treatment options being used are curettage with bone graft or bone cement, resection with arthrodesis, reconstruction, radiation, and chemotherapy. We are reporting a case of giant-cell tumour of right proximal radius in a 50-year-old female with posterior interosseous nerve palsy. It is very rare, and only four cases have been reported in the literature. It was treated by wide margin resection with fibular grafting, titanium elastic nail system along with cancellous bone graft reconstruction.

Остеосинтез в хирургическом лечении метастазов в длинных трубчатых костях

Objectives. This study was designed to investigate the causes and risk factors of complications requiring revision surgeries after intramedullary and plate osteosynthesis of the long tubular bones affected by metastases. Methods. Surgical treatment outcomes of patients with long tubular bones metastases (n=44) were analyzed retrospectively. Twelve patients had solitary skeletal metastasis, eleven multiple, twenty one bone metastases combined with visceral metastases. The pathological fracture was diagnosed in 35 patients and the threat of the pathological fracture in 9. Intramedullary osteosynthesis was carried out in 34 cases, plate osteosynthesis in 3 cases, intramedullary osteosynthesis with alloplasty in 12 cases. Results. Application of OS in the metastatic treatment of malignant tumors in long tubular bones have allowed saving the extremity function in 75% cases; the revision organ-saving surgery was carried out in 14,6% observations; restoration of the extremity function was failed in 10,4% cases. Thirteen complications caused by bone metastases required the revision surgery. Median time was 6 months (range of 1-12 months). The causes of complications included local tumor progression, the absence of osseous consolidation and violation of the structural integrity. Risk factors of complications development which require the revision surgeries were the following: pathologic fracture (p=0,046), progressive renal cell carcinoma (p=0,013) and radiation therapy before surgery (p=0,029). In patients with the best life prognosis the complications related with violation of the metal construction integrity or bone fixation failure have developed in longer and active load on the extremity. Conclusion. Osteosynthesis appears to be an efficient method in the treatment of metastatic bone disease in the specific clinical cases. Radical surgical removal of the metastases with the elimination of the bone defect by allograft or endoprosthesis is more reasonable in case of solitary metastases of radio-resistant tumors and controlled tumor process.

A comparative Study of Immunohistochemical Expression of Tumor Necrosis Factor-Alpha, Interleukin-6and Vascular Endothelial Growth Factor in Giant Cell Granuloma of the Jaws and Giant Cell Tumor of Long Bones

Background: Central giant cell granuloma (CGCG) and peripheral giant cell granuloma(PGCG) are pathological conditions of the jaws that share the same microscopic features, but differ clinically in terms of their behavior. While the giant cell tumor (GCT) of long bones is a rare benign neoplasm, tend to affect femur and tubular bone, characterized by local aggressiveness, high recur- rence rates and metastasis to the lung. Objectives: To evaluate, compare and correlate the expression of TNF-α, IL-6 and VEGF in peripheral and central giant cell granu - loma of the jaw and giant cell tumor of long bones. Methods: A total of 60 retrospective formalin- fixed, paraffine-embeded specimens of giant cell lesions of the jaws and long bones, where included in this study. An immunohistochemical staining with TNF-α , IL-6 and VEGF monoclonal antibodies were performed. Results: TNF-α, IL-6 and VEGF were expressedin all lesions. The PGCG comparedto the CGCG and GCT showed significantly in - creased expression of TNF-α and decreased expression of VEGF by the stromal cells..GCT showed increased expression of VEGF by M NGCs and stromal cells .There is a non significant difference between CGCG and GCT regarding the expression of all three cytokines. Conclusions: The present study confirmed the usefulness TNF-α,IL-6 and VEGF in evaluating osteoclastogenesis. The results of this study proved that the biological activity of TNF-α, IL-6 and VEGF was comparable between the central giant cell granuloma and giant cell tumors, supporting the observations that these two lesions are the same entity and have the same biological behavior.

Mesenchymal Chondrosarcoma of Maxilla: A Rare Case Report

Chondrosarcoma (CS) is a malignant tumor of long and flat bone characterized by the formation of cartilage. Mesenchymal chondrosarcoma is a rare variety of chondrosarcoma .It is a biphasic tumor with areas of spindle cell mesenchyme along with chondroid differentiation in the connective tissue stroma. A 17 year old male presented to us as a painless mass in maxilla. Contrast enhanced computed tomography (CECT) showed a lytic expansile lesion in the right maxillary bone with foci of calcification within soft tissue lesion. Fine needle aspiration cytology (FNAC) and incisional biopsy was performed which confirmed the diagnosis of maxillary Mesenchymal chondrosarcoma .The patient underwent right subtotal maxillectomy with 2 cm margins. The review of literature shows that very lesser number of maxillary Mesenchymal chondrosarcoma cases were reported so far. Therefore an attempt is made to add this rare case of MC of maxillary alveolus in the Existing literature.

Proximal location in extremity long bones is a poor prognostic factor for osteosarcoma: A retrospective cohort study of 153 patients

Background: Osteosarcomas arising in the proximal femur, humerus, and tibia appear to have poorer outcomes than those arising in distal long bones. However, the strength of this association is uncertain, particularly in light of other prognostic factors. Therefore, this retrospective cohort study was performed to compare patient outcomes between proximal and distal tumor location within extremity long bones. Material and methods: A total of 153 patients with conventional high-grade osteosarcoma of the extremity long bones, pelvis, or axial skeleton who had undergone neoadjuvant chemotherapy and surgical resection between 1985 and 2010 were identified in the Surgical Pathology files at Vanderbilt Medical Center. Effect of anatomic location within a proximal long bone was assessed using multivariable Cox proportional hazard regression. Results: Proximal tumor location was a strong predictor of poor prognosis in univariate survival analysis. Multivariate regression analysis showed that after controlling for American Joint Committee on Cancer (AJCC) stage, histologic response to chemotherapy, surgical resection margin status, and histologic type, location in the proximal femur, tibia, and humerus were independent risk factors for death due to osteosarcoma, but not event-free survival. Conclusion: Osteosarcomas of the proximal extremity long bones are associated with decreased disease-specific survival compared to tumors of the distal long bones, even after accounting for other key prognostic covariates.