Intramedullary Osteosarcoma Research Articles

The many faces of mouse histiocytic sarcoma in C57BL/6J mice.

Histiocytic sarcoma is a tumor of the hematopoietic system considered to be derived from macrophages. Although rare in humans, it occurs frequently in mice. Histiocytic sarcoma can be a difficult tumor to diagnose due to its diverse cellular morphologies, growth patterns, and organ distributions. The varying morphology of histiocytic sarcomas makes it easy to confuse them with other types of neoplasia, including hepatic hemangiosarcoma, uterine schwannoma, leiomyosarcoma, uterine stromal cell tumor, intramedullary osteosarcoma, and myeloid leukemia. As such, immunohistochemistry (IHC) is often needed to differentiate histiocytic sarcomas from other common tumors in mice that they can morphologically mimic. The goal of this article is to present a broader perspective of the diverse cellular morphologies, growth patterns, organ distributions, and IHC labeling of histiocytic sarcomas encountered by the authors. This article describes these features in a set of 62 mouse histiocytic sarcomas, including the IHC characterization of the tumors using a panel of markers for the macrophage antigens F4/80, IBA1, MAC2, CD163, CD68, and lysozyme, and describes differentiating features of histiocytic sarcomas from other morphologically similar tumors. The genetic changes underlying the pathogenesis of histiocytic sarcoma in humans are beginning to be elucidated, but this is difficult due to its rarity. The higher prevalence of this tumor in mice provides opportunities to investigate mechanisms of its development and to test potential treatments.

Osteosarcoma of orbital bone-chondroblastic morphology mimics to chondrosarcoma-A rare case report & review of literature

Conventional osteosarcoma, a subgroup of intramedullary osteosarcoma(OS) ,is the most common osteosarcoma that occurs in adolescents and early adulthood. We present a case of 22‑year‑old male patient with the chief complaint of proptosis, pain and swelling in the left orbital region & diagnosed as chrondoblastic osteosarcoma(COS) of left orbital bone. COS is very rare at orbital location, this report aimed to discuss clinical, radiographic, histopathologic, IHC findings and diagnostic pitfalls & manangement of COS in view of the literature.

T2-weighted MRI radiomics in high-grade intramedullary osteosarcoma: predictive accuracy in assessing histologic response to chemotherapy, overall survival, and disease-free survival.

To analyze radiomic features obtained from pre-treatment T2-weighted MRI acquisitions in patients with histologically proven intramedullary high-grade osteosarcomas and assess the accuracy of radiomic modelling as predictive biomarker of tumor necrosis following neoadjuvant chemotherapy (NAC), overall survival (OS), and disease-free survival (DFS). Pre-treatment MRI exams in 105 consecutive patients who underwent NAC and resection of high-grade intramedullary osteosarcoma were evaluated. Histologic necrosis following NAC, and clinical outcome-survival data was collected for each case. Radiomic features were extracted from segmentations performed by two readers, with poorly reproducible features excluded from further analysis. Cox proportional hazard model and Spearman correlation with multivariable modelling were used for assessing relationships of radiomics features with OS, DFS, and histologic tumor necrosis. Study included 74 males, 31 females (mean 32.5yrs, range 15-77years). Histologic assessment of tumor necrosis following NAC was available in 104 cases, with good response (≥ 90% necrosis) in 41, and poor response in 63. Fifty-three of 105 patients were alive at follow-up (median 40months, range: 2-213months). Median OS was 89months. Excluding 14 patients with metastases at presentation, median DFS was 19months. Eleven radiomics features were employed in final radiomics model predicting histologic tumor necrosis (mean AUC 0.708 ± 0.046). Thirteen radiomic features were used in model predicting OS (mean concordance index 0.741 ± 0.011), and 12 features retained in predicting DFS (mean concordance index 0.745 ± 0.010). T2-weighted MRI radiomic models demonstrate promising results as potential prognostic biomarkers of prospective tumor response to neoadjuvant chemotherapy and prediction of clinical outcomes in conventional osteosarcoma.

Fibrocartilaginous dysplasia (fibrous dysplasia and massive cartilaginous differentiation): Case report and literature review

Fibrocartilaginous dysplasia (fibrous dysplasia and massive cartilaginous differentiation or fibrochondroplasia, FCD) is a rare variant of fibrous dysplasia and a term used for cases of fibrous dysplasia with prominent cartilage tissue. A limited number of FCD cases have been reported in the literature, which can be seen in both clinical forms.
 A 16-year-old male patient, who had been followed for ten years with a diagnosis of polyostotic fibrous dysplasia in the left hip and cranium, presented with pain in the left leg after a fall. A subtrochanteric pathological fracture in the left femur was detected on exam, the lesion area was curetted, and osteotomy and fixation were applied. Microscopic assessment revealed a fibro-osseous lesion of benign spindle cell fibrous connective tissue with woven bone trabeculae, without osteoblastic rim or large areas of benign cartilage nodules. The final diagnosis was fibrocartilaginous dysplasia. In our literature review, 26 cases of FCD were reported so far. Age distribution of patients ranged from 4 to 53 years (mean 15.9) and the male / female ratio was 15/11 = 1.36. Eighteen cases were monostotic, and 8 were polyostotic. In cases with noted clinical and follow-up data, symptom duration ranged from 8 weeks to 18 years (mean 62.2 months), with no recurrence or malignant transformation in a mean follow-up of 21.71 (2-60) months post-treatment. In the cartilage component, there was increased cellularity, some nuclear atypia, binucleation, and myxoid degeneration. This situation simulates benign and malignant entities such as enchondroma, fibrocartilaginous mesenchymoma, well-differentiated intramedullary osteosarcoma, and chondrosarcoma with a differential diagnosis. FCD is a benign and very rare lesion with a prominent chondroid component, but may cause difficulty with differential diagnosis. Awareness of the histopathological and radiological features of FCD cases, their age range, and involvement areas provides an approach to distinguish them from lesions that may be confusing in a differential diagnosis.

A review of imaging of surface sarcomas of bone.

Surface lesions of bone are uncommon. Although their imaging features generally mirror those of their intramedullary counterparts, surface lesions may demonstrate distinct characteristics which along with their unusual location present a diagnostic challenge. Surface sarcomas are usually of a lower grade compared with intramedullary variants, leading to differences in management. Osteosarcoma arising from the cortical surface of the bone is termed juxtacortical or surface osteosarcoma and includes three distinct entities: parosteal, periosteal, and high-grade surface osteosarcoma. We also review the features intracortical osteosarcoma, which some authors include under the umbrella term surface osteosarcoma. These lesions exhibit biologic features distinct from those of conventional intramedullary osteosarcoma, which underlines the importance of accurate imaging diagnosis. Periosteal chondrosarcoma and periosteal Ewing sarcoma also have distinctive imaging appearances. The purpose of this article is to review surface sarcomas of bone with regard to their clinical and radiological features and to discuss the differential diagnosis for each condition.

The effect of preoperative radiotherapy on local control and prognosis in high-grade non-metastatic intramedullary osteosarcoma of the extremities.

This study aimed to analyse the effect of preoperative radiotherapy on survival, recurrence and necrosis rates in osteosarcoma patients treated with neoadjuvant chemotherapy and limb-salvage surgery. Osteosarcoma patients who referred to our clinic from 1998 to 2015 were investigated retrospectively. 141 patients with non-metastatic osteosarcoma of the limb who received neoadjuvant chemotherapy and underwent limb-sparing surgery with or without preoperative radiotherapy were included in the study. 73 patients had neoadjuvant chemotherapy only (CT group), while 68 patients had additional preoperative radiotherapy (CT + RT group). 5-year survival, disease-free survival, limb survival, local recurrence, metastasis, complication and necrosis rates were compared between the two groups. Overall 5-year survival, 5-year disease-free survival, 5-year limb survival rates were 68.5, 64.3, 65.7 for CT group and 72.1, 67.6, 64.7 for CT + RT group, respectively. Preoperative radiotherapy gave similar survival and disease-free survival rates. Limb survival, recurrence and metastasis rates were similar between the groups. The necrosis rate of the lesions was significantly higher in the CT + RT group compared to the CT group. Preoperative radiotherapy can provide a higher necrosis rate and may allow the resection of unresectable lesions in the treatment of osteosarcoma. CT + RT provided similar 5-year survival despite the larger tumour size compared to CT group. Due to the higher wound complication rate (8.2% in CT, 23.5% in CT + RT group, p = 0.01), CT + RT should be restricted to the lesions with large size or close proximity to neurovascular structures. Level III; Therapeutic, Retrospective comparative study.

Desmoplastic fibroma of the tibia: review of the literature and case presentation of an unusual huge lesion

Desmoplastic fibroma is a benign, rare fibroblastic intraosseous neoplasm histologically resembling a desmoid soft-tissue tumor. Fewer than 300 such tumors have been reported in the literature worldwide. Radiographic differential diagnoses include tuberculosis, chondromyxoid fibroma, low-grade intramedullary osteosarcoma, and fibrosarcoma. Recurrence rate after curettage reaches up to 72%, thus en bloc resection with a wide margin of normal tissue is the treatment of choice. This article presents a case of an exceptionally large desmoplastic fibroma of the tibia, discussing the diagnosis and treatment as well as a review of the literature.

Ankle ligament reconstruction after wide resection of the osteosarcoma of the distal fibula: a case report

BackgroundRestoration of the lateral ankle after distal fibulectomy is a difficult reconstructive procedure. Many surgical techniques have been proposed. This report shows another fibular reconstructive option with promising outcome.Case presentationWe report the case of a 30-year-old woman who presented with a solitary mass located in the lateral aspect of the ankle. The mass had grown rapidly for 2 months and caused increasing pain. Physical examination showed a 3.0 cm diameter tender, nonmobile hard mass in the lateral malleolus. Radiographs showed an osteolytic lesion involving the lateral cortex at the distal fibula. After incisional biopsy, pathologic examination found a well-differentiated intramedullary osteosarcoma. Neoadjuvant chemotherapy with doxorubicin was provided for 3 months prior to definitive surgical treatment. Magnetic resonance imaging showed persistent tumor in the biopsy site. After distal fibulectomy and wide resection, split tibialis posterior tendon transfer to the remaining peroneus brevis restored the stability of the ankle. The pain resolved within 3 months. The ankle was stable and no recurrence of the cancer was found at a 7 year follow-up.ConclusionReconstruction following distal fibulectomy and surrounding soft tissue resection responds favorably to split tibialis posterior transfer to the remaining peroneus brevis suggesting that this technique can provide a good and functional outcome.

Neglected telangiectatic osteosarcoma of the femur presenting as surgical emergency

Introduction: telangiectatic osteosarcoma is a rare and aggressive subtype of intramedullary osteosarcoma. the distal femur is the most common site. case report: We present a case of telangiectatic osteosarcoma of the femur in a 15-year-old male. the tumor was neglected for six months. the patient had severe anemia with hemoglobin of 5 g/dL. radiography showed an expansive lytic lesion of the distal end of the femur with cortical destruction, focal periosteal reaction and a pathologic fracture. It showed massive extension to adjacent soft tissue. Given the advanced stage of the disease, an amputation of the limb was performed. Gross examination of the resected distal femur revealed a 22x5 cm intramedullary multicystic hemorrhagic and destructive tumor with cortical destruction and extension into the adjacent soft tissues. Histologically, the tumor showed blood-filled spaces lined by giant cells, separated by septa with malignant tumor cells. An immature bone osteoid kind was observed. Numerous mitotic figures were noted. the resection

Intramedullary osteosarcoma of the mandible: a clinicoradiologic perspective.

Osteosarcoma is a non-hematopoietic primary malignant tumor of bone or mesenchymal tissue. Although osteosarcoma is not a common malignant bone tumor, accounting for approximately 20% of sarcomas, tumor of the jaw bone is uncommon, representing only about 4% of osteosarcomas of long bones. We report a case of a 72-year-old female with a swelling on the left side of the mandible and intra-oral swelling on the floor of the mouth. Conventional radiograph and advanced imaging modalities such as computed tomography and magnetic resonance imaging revealed an intramedullary osteosarcoma of the mandible. This report highlights importance of imaging modalities in the diagnosis of malignant tumors of the jaws.

Atypical Presentation of High-Grade Intramedullary Osteosarcoma with Bilateral Cervical, Supraclavicular, and Axillary Lymphadenopathy: A Case Report and Literature Review

Osteosarcoma typically presents with primary site pain. The authors report a case of extensive metastatic osteosarcoma without any complaint of primary site pain during initial presentation. The 23-year-old female patient presented with simultaneous multiple cervical, supraclavicular, and axillary lymphadenopathy, as well as two large subcutaneous fat tumours. Despite initial excision biopsy of cervical lymph nodes, the diagnosis of osteosarcoma was only clinched after open biopsy of the right distal femur lesions and further histological evaluation. Though the patient was promptly started on neo-adjuvant chemotherapy and achieved excellent histological response to treatment, the disease had relapsed quickly and she succumbed to the disease one year after initial presentation. This report highlights the need to be vigilant in the workup and investigation of osteosarcoma, as the presenting symptoms may be more heterogenous than the conventional teaching of primary site pain.

Locally aggressive fibrous dysplasia

Although fibrous dysplasia (FD) is a benign fibro-osseous lesion, locally aggressive behaviour has rarely been described but is poorly characterised. In this study, we document clinical, radiological and pathological (including molecular genetics) findings in three cases of locally aggressive FD, two of which involved the ribs. Lesions in these cases, one of which was a recurrent lesion, were followed up for 2-7 years. All of the lesions showed typical histological features of FD but were characterised by extension through the bone cortex into the extra-osseous soft tissue. The lesions did not exhibit overexpression/amplification of CDK4 and MDM2; in two of the cases, a GNAS mutation was identified. Our findings confirm that FD can rarely exhibit locally aggressive behaviour with extension beyond the bone compartment into the surrounding soft tissue; these lesions can be distinguished from low-grade intramedullary osteosarcoma by lack of amplification/overexpression of CDK4 and MDM2 and the presence of a GNAS mutation.

Preoperative easily misdiagnosed telangiectatic osteosarcoma: clinical

Purpose: To describe the clinical, imaging, and pathologic characteristics and diagnostic methods of telangiectatic osteosarcoma (TOS) for improving the diagnostic level. Materials and methods: The authors retrospectively reviewed patient demographics, serum alkaline phosphatase (AKP) levels, preoperative biopsy pathologic reports, pathologic materials, imaging findings, and treatment outcomes from 26 patients with TOS. Patient images from radiography (26 cases) and magnetic resonance (MR) imaging (22 cases) were evaluated by 3 authors in consensus for intrinsic characteristics. There were 15 male and 11 female patients in the study, with an age of 9–32 years (mean age 15.9 years). Results: Eighteen of 26 patients died of lung metastases within 5 years of follow-up. The distal femur was affected more commonly (14 cases, 53.8%). Regarding serum AKP, normal (8 cases) or mildly elevated (18 cases) levels were found before preoperative chemotherapy. Radiographs showed geographic bone lysis without sclerotic margin (26 cases), cortical destruction (26 cases), periosteal new bone formation (24 cases), soft-tissue mass (23 cases), and matrix mineralization (4 cases). The aggressive radiographic features of TOS simulated the appearance of conventional high-grade intramedullary osteosarcoma, though different from aneurysmal bone cyst. MR images demonstrated multiple big (16 cases) or small (6 cases) cystic spaces, fluid-fluid levels (14 cases), soft-tissue mass (22 cases), and thick peripheral and septal enhancement (22 cases). Nine of 26 cases were misdiagnosed as aneurysmal bone cysts by preoperative core-needle biopsy, owing to the absence of viable high-grade sarcomatous cells in the small tissue samples. Conclusion: The aggressive growth pattern with occasional matrix mineralization, and multiple big or small fluid-filled cavities with thick peripheral, septal, and nodular tissue surrounding the fluid-filled cavities are characteristic imaging features of TOS, and these features are helpful in making the correct preoperative diagnosis of TOS.

Demographic Determinants of Survival in Osteosarcoma

Osteosarcoma treatment has experienced a renaissance in the last 3 decades with the institution of multimodality treatment involving multiagent chemotherapy and surgery. Yet globally, treatment success has stagnated at about 70% survival at 5 years in most single institution series. We performed survival analyses on 2 national databases in 2 countries and compared these with corresponding institution specific survival. All patients with the diagnostic code of non-metastatic intramedullary osteosarcoma in the long bones of the upper and lower limbs less than 30 years of age were selected from the Surveillance Epidemiology and End Result (SEER) database to ensure uniformity with respect to disease and treatment. We studied the factors: ethnicity, gender, age, grade, histology, size, site, surgery, compartmentalisation, number of primaries and venue of treatment for their contribution to survival. In addition, the data were stratified into 3 decades (seventies, eighties and nineties) to account for variations due to the evolution of treatment paradigms and imaging modalities. Institution-specific survival was predictably better than national survival in the 4 databases. One thousand patients were selected from the SEER database. Oriental descent, state-specific treatment, female gender, treatment in the nineties, low-grade disease, intra-compartmental disease, small size, wide resections as opposed to forequarter or hindquarter amputations, and single primaries were good prognostic factors on univariate analysis as well as multivariate analysis (P <0.05). Survival was better in the more affluent states (P <0.05). Males were affected at an older age than females (P = 0.004). Blacks tended to have larger tumours although their overall survival was similar to whites. Orientals were more likely to be treated in the nineties with wide resections for smaller tumours and were located around states associated with good treatment. Orientals in Singapore and the United States had the same survival (P = 0.45). Survival in Orientals in Singapore was not significantly different from other races. The standard of healthcare for osteosarcoma varies greatly across the United States but is uniform in Singapore. Hence the observed differences in the United States were likely due to socioeconomic factors. This analysis confirms the importance of a number of prognostic variables in osteosarcoma and suggests the possibility of an ethnic and economic bias for good survival.

Abstract 5075: Genome-wide analysis of DNA copy number variations in osteosarcoma

Abstract Objectives: Copy number variations (CNVs) such as deletions, amplifications and duplications across the whole genome may contribute to Osteosarcoma (OS) tumorigenesis. Detection of genomic regions containing these changes is extremely important for both the basic understanding of OS and its diagnosis. In this study we performed Whole Genome Genotyping (WGG) using high-density SNP arrays to detect CNVs in OS tumors and blood. A major advantage of this technology is the simultaneous detection of both allelic frequencies and CNVs. Methods: WGG analysis was performed using 35 high-grade intramedullary OS and 8 parosteal sarcoma tumor DNAs. 10 matching germline DNAs from blood were also included into the analysis. 250 nanograms of DNA were hybridized onto the Illumina 610 Quad BeadChips using the Infinium II WGG assay. The WGG data was analysed using Bead Studio and Partek software. Results: SNP array based Whole Genome Genotyping revealed a large number of chromosomal aberrations in OS. Preliminary analysis of 35 OS tumor DNAs showed high levels of recurrent amplification of 1p36, 3p12.1, 6q14, 12q13-15, 17p11.2, 20p12; and deletion of 3q26.31, 6p21, 6q16.3, 7q21, 7q35, 8q24.13, 9p21 and 17p13 regions. Parosteal tumor DNAs displayed a high level of amplification of the 12q13-15 amplicon. Amplification status of genes from 17p11.2 (PMP22, NCOR1, COPS3 and TOM1L2) and 12q14 (CDK4 and MDM2) was validated by Real-Time PCR. Some tumors exhibited whole chromosome arm deletions and/or duplications. Conclusions: OS tumors exhibit chromosomal alterations that can be detected using WGG. Comparison of normal and tumour DNAs from the same subjects can be used to identify CNV associated with OS development and progression. Current analyses include comparisons of CNV data and gene expression profiles of the same OS tumours to discover genes that may be biologically relevant targets in OS. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5075. doi:1538-7445.AM2012-5075

Local recurrence of osteosarcoma after 17 years

The recurrence of osteosarcoma is rare. Local recurrence occurs in 4-10% of patients following effective treatment. So far, recurrences as late as 15 years have been reported in the literature. We report a unique case of local recurrence of intramedullary osteosarcoma 17 years from initial diagnosis and treatment. Regular long-term follow-up of patients with this diagnosis is crucial to ensure early detection and treatment of potential recurrences.

Low-Grade Intramedullary Osteosarcoma of the Tibia Presenting as an Intracortical Lesion

Intramedullary or intraosseous osteosarcomas are the most common subtype of osteosarcoma, followed in frequency by parosteal and periosteal osteosarcomas, with intracortical osteosarcomas representing the rarest type. The diagnosis and classification of osteosarcomas can be complicated or delayed when these lesions masquerade as benign bone lesions. This article presents a case of a low-grade osteosarcoma arising in the tibia of a 19-year-old man, which had radiographic features most suggestive of a benign entity.

Selected Papers Presented at the 2007 Meeting of the Musculoskeletal Tumor Society: Editorial Comment

The meritorious papers selected from the 2007 MSTS meeting comprise a wide range of topics. They underscore the fascinating breadth of orthopaedic oncology. Although the articles are diverse in content, they reflect important areas of research where data are lacking. One of the challenges in clinical care of patients with metastatic bone disease is how to determine whether a destructive lesion should be stabilized. Assessing the risk of impending fracture is imprecise, and efforts have been made in the past 5 years to utilize more precise imaging techniques to outline indications for treatment. The Mirels classification is widely used as a guideline to stabilize impending fractures, but it was originally validated only for the femur. Evans et al. in this symposium have utilized the Mirels scoring tool to evaluate pathologic lesions in the humerus. From the same institution, Mann et al. are tackling the issue from a more translational angle by developing a murine model of osteolysis. By using noninvasive imaging and finite element modeling, they have developed an algorithm by which to estimate bone strength in the setting of osteolytic lesions. We applaud the institutional efforts to study this problem from both basic science and clinical perspectives. The survival of patients with osteosarcoma has not changed substantially in the past 25 years and this is another area where both clinical and basic research efforts are needed. The article by Hugate et al. provides the latest update of a series of 53 patients with osteosarcoma or malignant fibrous histiocytoma of bone treated with intraarterial cisplatinum combined with more traditional intravenous chemotherapy. These patients had an 82% 10-year survival and there was a suggestion of improved local tumor necrosis and ease of surgical resection when compared historically with series of patients treated by standard intravenous protocols. From a translational perspective, Sorenson et al. have developed a murine model of metastatic osteosarcoma. They are evaluating treatment using Salmonella typhimurium with or without interleukin-2 in order to cause tumor cell death and harness the power of the local immune system, respectively. This translational work is vital if we hope to improve the survival of patients with osteosarcoma over the next 25 years. The remaining articles within this collection are unrelated but will improve patient care and contribute to the education of the next generation of orthopaedic oncologists. Sawamura et al. evaluated a large series of patients treated with rotationplasty for bone sarcomas. They critically investigated the complications associated with this unusual procedure and provided insight into which patients should be indicated for this treatment. Institutions with a long history of orthopaedic oncology have the opportunity to evaluate rare tumors or procedures and this is highly encouraged. Damron et al. have retrospectively reviewed a rare surgical reconstructive tool, the intercalary humeral spacer. With a new design, this spacer provides excellent stability in uniquely selected patients with humeral diaphyseal lesions. Schwab et al. have reviewed the extensive records at Memorial Sloan-Kettering Cancer Center in order to better distinguish the clinical behavior of two histologically similar tumors: low grade juxtacortical osteosarcoma and low grade intramedullary osteosarcoma. They reported indistinguishable rates of recurrence and metastasis. Finally, Frassica et al. critically reviewed the pathology questions on the Orthopaedic In Training Examination for the past five years. They evaluated the specific content and question types in order to identify how to better teach residents prior to the examination. We compliment the authors on their efforts to bring this information to the orthopaedic community. The data advance the field of orthopaedic oncology and hopefully stimulate others to investigate related research areas. These authors submitted completed manuscripts shortly after the MSTS meeting, and we wish to encourage such timely submissions in the future.

High-grade Intramedullary Osteosarcoma of the Talus: Case Report

This is a presentation of a rare malignant tumor that uncommonly affects the bones of the foot. The following case involves a malignancy which usually presents during childhood or adolescence presenting much later in life. Physicians treating the foot and ankle must include osteosarcoma in their list of differential diagnoses to exclude when vague symptoms involving deep pain and edema present. It is critical to prevent misdiagnosis and delayed treatment with this form of tumor.

Expression of cell cycle, angiogenesis and metastases associated factors in osteosarcoma - immunohistochemical analysis of tissue array in 35 patients

10036 Background: Osteosarcoma is the most common, non-haemopoietic primary malignant tumor of bone. A variety of biological markers have been investigated for their prognostic value with variable results. This study is aimed to assess the prognostic and biological value of biological markers involved in cell cycle checkpoint regulation (p53 family, p16, and PTEN), cell adhesion, motility and invasion (ezrin and beta catenin), angiogenesis (VEGF and PlGF) in tumor samples of osteosarcoma patients. Methods: Thirty-five patients were chosen for the study (ages 6–74 years, median age - 15 years). Among them, 32 were high-grade conventional intramedullary osteosarcoma, and 3 were Paget osteosarcomas. Eight patients presented with metastases. Immunohistochemical analysis was performed on a tissue array of tumor samples with standard protocol. Clinical outcome was measured as events (metastasis or death), chemo-response (stage), and survival by multivariate analysis. Analysis also included our previous reported results of p53, p63 and p73. Results: Staining was assessed based upon semi-quantitative manual scoring. Appropriate staining (nuclear or cytoplasmic) of &gt;5% in tumor cells was considered as positive for all markers. The percentage positivity for the markers is as follows: p53 =29%, p63 =37%, p73= 9%, p16 =60%, PTEN=83%, ezrin =77%, beta catenin =91%, VEGF= 86% and PlGF =54%. There was no association of marker expression with specific subtype or location. Statistical analysis revealed no significant association between the positivity of these markers with clinical outcomes. Expression of ezrin was observed in all eight patients with metastases, although this finding did not approach statistical significance (P = 0.15). There was significant association between ezrin and P63 (P &lt; 0.05). Conclusions: 1. Expression of p53 family proteins, p16, PTEN, ezrin, beta catenin, VEGF, and PlGF are not significant predictors of clinical outcome in osteosarcoma patients. 2. Ezrin may be essential for osteosarcoma metastases. 3. No significant association between VEGF, PlGF and metastases. 4. The positive association between ezrin and P63 is interesting and need to be evaluated further. No significant financial relationships to disclose.