Osteogenic Osteosarcoma Research Articles

Osteosarcoma of Jaw Masquerading as Calcifying Epithelial Odontogenic Tumour- A Diagnostic Dilemma

Osteogenic osteosarcoma is the most widely recognised primary malignant bone tumour involving particularly the appendicular skeleton. Osteosarcoma of jaw including maxillary and mandibular osteosarcoma accounts for about 7% of cases. The variants of osteosarcoma involving jaw include- osteosarcoma, Not Otherwise Specified (NOS) Low grade central osteosarcoma; chondroblastic osteosarcoma; parosteal osteosarcoma; periosteal Osteosarcoma. The present case was a 27-year-old male who came to the dental Outpatient Department (OPD) with the complaints of swelling in the upper vestibule and loosening of upper alveolar teeth and was reported as Calcifying Epithelial Odontogenic Tumour (CEOT) on histopathological examination and excision of the lesion was done. After two months the patient again presented with a recurrent lytic and sclerotic lesion involving the left maxillary bone with soft tissue extension in the maxillary sinus. Provisional diagnosis was made as malignant transformation of CEOT and immunohistochemistry was performed for the confirmation of the diagnosis. This case represented the challenges in the diagnosis of osteosarcoma of jaw which can be due to difficult biopsy procedure; limited imaging and challenges in legitimate resection because of the proximity to essential structures and the challenges are being faced to get the optimal treatment of jaw osteosarcoma.

Unexpected Metastasis to Breast, Lymph Node, Subcutaneous, Abdominal Wall, Intraabdominal, and Bone in Osteogenic Osteosarcoma: An Unusual Presentation on Bone Scintigraphy.

Osteogenic osteosarcoma is an aggressive malignant bone tumor with the tendency for local invasion and early metastases. Radionuclide bone scans play an important role in disease management by identifying other areas of skeletal involvement as well as extraosseous metastases. Osteogenic sarcoma metastasis is known to accumulate bone-avid agents due to their osteogenic potential. Here, we report a case of osteogenic osteosarcoma of distal femur with the absence of pleural effusion but extensive extraosseous areas of metastatic involvement in distant lymph nodes, subcutaneous planes (in the form of nodules), abdominal wall, multiple intraperitoneal deposits, breast, and bone metastases visualized on preoperative Tc-99 m methylene diphosphonate bone scan.

Abstract 82: Transforming of human osteoblasts with the combination of hTERT (T), SV40Tag (S) and c-Myc: Changes in phenotype and tumorigenesis capability

Abstract The etiology of osteosarcoma (OS), the most common primary malignant bone cancer in pediatric patients, still remains unknown. It is not clear where tat which point he osteosarcoma is originated from the osteogenic lineagein the osteogenic osteosarcoma arises., some consider Potential candidates in the literature include the human mesenchymal cells (hMSC) as the cell of origin in OS, whereas others believe theand osteoblast (OB) to be the most likely cell of origin. To understand the origin and molecular pathogenesis of osteosarcoma, we have transformed hMSCs and OBs differentiated from the same MSC with oncogenes hTERT (T), SV40Tag (S) and H-RAS (R) in series to check evaluate for spindle cell tumor formation in mice. Transformed MSC did not form osteoid, whereas OB-TSR tumor showed only scant production of osteoid, suggesting MSC may not be the origin of OS and the hTERT, SV40Tag and h-Ras may not be sufficient for osteoblast to form OS. C-Myc is one of the genes that play a major role in oncogenic transformation of normal cells. It has been shown that c-Myc is overexpressed in OS cells and more than 10% OS patients carry c-Myc amplification mutations. We further decide to look intoThis served as the basis to examine the role of c-Myc in OS formation in the background of cells transformed by hTERT and SV40. OB transformed with hTERT and SV40Tag cells were further transfected with a retrovirus containing human c-Myc to obtain stable cell lines. Quantitative PCR and western blots assays detected both gene and protein expression patterns of c-Myc, respectively, in the transformed cell lines. Transformed cell lines were analyzed for proliferation, invasion, migration, and spheroid formation to determine the tumorigenic capacity capability. TThe tumorigenesis capability is found to be correlated with the level of c-Myc expression level based onby RT-PCR data. Furthermore, we used RNA-seq to analyze gene expression profiles of the transformed cell lines, compared with those forin comparison to primary OS cell lines and patient derived xenografts (PDXs). In -vivo tumorigenic assays, histological examination for osteoid production and chromosome analysis are still under way. Our study using an osteosarcoma model with transformed human cells may provide new insights on the cell origin of OS. Citation Format: Zhongting Zhang, Yifei Wang, Wendong Zhang, Michael Roth, Jonathan Benjamin Gill, Zhaohui Xu, Xiangjun Tian, Jing Wang, Richard Gorlick. Transforming of human osteoblasts with the combination of hTERT (T), SV40Tag (S) and c-Myc: Changes in phenotype and tumorigenesis capability [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 82.

Primary osteogenic osteosarcoma of the left zygomatic arch - A case report

Primary osteogenic osteosarcoma of the left zygomatic arch - A case report

Extraskeletal osteosarcoma: nosologocal diversity, morphology, differential diagnosis, and features of metastasis

Extraskeletal osteosarcoma is a rare malignant tumor with histologic similarities to primary bone osteosarcoma. However, there are distinct differences in epidemiology, imaging features, biological characteristics, prognosis, and management compared with osteogenic osteosarcoma. Extraskeletal osteosarcoma is usually characterized as high-grade neoplasm with clinically aggressive behavior, poor prognosis, frequent recurrence/lymphogenic metastatsis, and resistence to chemotherapy. A noteworthy feature of extraskeletal osteosarcoma is the fact that almost all existing biological phenomena described in mesenchymal oncopathology (except primary-multiple lesions) are present in this tumor, namely: secondary malignancy, association with syndromes, partial spontaneous regression of the tumor, dedifferentiation, bone invasion, biphasic pathology. In this paper, we have discussed in detail the tumor morphology, histological subtypes, prognostic factors and differential diagnosis.

Meta-analysis of clinical significance of p53 protein expression in patients with osteosarcoma.

The prognostic role of p53 protein expression in osteosarcoma has been reported, but the results remain conflicting. The relevant literature databases were searched to get eligible articles published in English. The overall ORs or HRs and their corresponding 95% CIs were calculated. The results indicated that p53 protein expression was not linked to age factor, gender, tumor grade, cancer metastasis and response to chemotherapy. p53 expression was significantly lower in osteogenic osteosarcoma than in nonosteogenic osteosarcoma (OR = 0.40; p = 0.006). p53 expression was associated with a poor prognosis of patients in overall survival (univariate analysis: HR: 2.49; p < 0.001 and multivariate analysis: HR: 2.92; p < 0.001). p53 expression was correlated with pathological type and may become a useful prognostic biomarker in overall survival in osteosarcoma.

Abstract 4270: UMR957: a new osteogenic osteosarcoma cell-line derived from an osteoprotegerin null mutant mouse

Abstract Background: Mouse osteosarcoma cell-lines enabling in vivo studies in syngeneic mouse strains are rare but important for preclinical studies. Existing cell-lines when injected are mainly osteolytic with a moderate tumor osteoid tissue formation. There is a crucial need for new cell-lines with higher osteogenic characteristic. Methods: A female osteoprotegerin null mutant mouse, breed in the animal house of the Faculty of Medicine from the University of Nantes (France), spontaneously developed an osteosarcoma on the left tibia. The mouse was sacrificed, a biopsy was place in culture for further in vitro and in vivo (injections) studies and the tumor was analyzed using μ-CT, μ-radiography, classical histology and immunohistochemistry. Results: μ-CT and μ-radiography analyses evidenced that the tumor developed in the Opg-/- mouse was highly osteogenic with an important tumor osteoid tissue that colonized most of the surrounding soft tissues. A total destruction of the tibia was observed. Histology and immunohistochemistry confirmed the presence of an osteosarcoma with an important expression of most bone markers as Osterix. An important vascularization was evidenced in the tumor as the presence of numerous TRAP positive cells. Monocyte/macrophage and T-lymphocyte cells were also present in this tumor. From the biopsy a cell-line was obtained and named UMR957. This cell-line evidenced all markers of the osteoblast cell. When injected in the tibia vicinity of either naïve C57BL/6J, Nude or Opg-/- mouse a highly osteogenic osteosarcoma was observed with similar features to the initial tumor. Conclusions: A new mouse osteosarcoma cell-line was obtained from a spontaneous tumor developed in an Opg-/- mouse. This cell-line when injected in syngeneic mouse recapitulates all features of the initial tumor more particularly its massive osteoid tissue formation. Citation Format: Benjamin Navet, Jérome Amiaud, Céline Charrier, Thibaut Quillard, Bénédicte Brounais-Le Royer, Dominique Heymann, Frederic P.R. Lezot. UMR957: a new osteogenic osteosarcoma cell-line derived from an osteoprotegerin null mutant mouse. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4270.

Temporal bone partial ostectomy via the temporomandibular joint to treat osteosarcoma of the caudal zygoma in a three-year-old Labrador retriever

A three years, seven-month-old male entire Labrador retriever was referred with a one-month history of pain when yawning and eating. CT revealed a 20×10×10 mm mass in the region of...

Abstract 1418: Screening and identification of key surface markers of mesenchymal stem cell osteogenic differentiation and osteosarcoma development

Abstract Introduction: Osteosarcoma (OS) is the most common primary malignant tumor of bone in children and young adults. Knowledge about its cell of origin is limited, making new treatments difficult to develop. Our aim is to screen and identify the key surface markers of mesenchymal stem cell (MSC) to osteogenic differentiation and OS malignant transformation. Methods: A list of differentially expressed genes with a statistically significant p-value &amp;lt;0.05 was obtained by microarray analysis from MSCs and osteoblasts (OB). MSCs were differentiated into osteoblasts, adipocytes and chondrocytes and confirmed by alizarin red staining, oil red O staining and collagen II immunohistchemistry, respectively. Western blots were then performed to identify the expression of selected surface markers during the MSC differentiation and compared to those of OS cells. Results: Nine genes were obtained with a p-value &amp;lt;0.02, which are differentially expressed between MSC and OB. Four of them were correlated with cell adhesion and metastasis. The expression profile of CD49b was distinct, where it was down regulated only during MSC osteogenic differentiation and over expressed in OS cell lines. Conclusions: Cell adhesion may have an important role during MSC differentiation. CD49b is a unique marker during MSC osteogenic differentiation and may play a significant role in osteoasarcoma malignant transformation. In the future we plan to determine the function and mechanism of CD49b during MSCs osteogenic differentiation and osteosarcoma malignant transformation in vitro. We will define the clinical significance of CD49b in osteosarcoma through immunohistochemistry of patient samples and functional analyses. Citation Format: Tingting Ren, Sajida Piperdi, Amy Y. Park, Richard Gorlick. Screening and identification of key surface markers of mesenchymal stem cell osteogenic differentiation and osteosarcoma development. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1418. doi:10.1158/1538-7445.AM2015-1418

Demethylation-mediated miR-129-5p up-regulation inhibits malignant phenotype of osteogenic osteosarcoma by targeting Homo sapiens valosin-containing protein (VCP).

Previous studies demonstrated that increased Homo sapiens valosin-containing protein (VCP) may be involved in osteosarcoma (OS) metastasis. However, the underlying mechanism of VCP over-expression in OS remains unknown. In the present study, we found a significantly negative correlation between miR-129-5p and VCP protein expression in OS tissues with pulmonary metastasis (Spearman's rho, rs = -0.948). Bioinformatical prediction, Luciferase reporter assay, Western blot, and RT-PCR assays performed on OS cells indicated that VCP is a target of miR-129-5p. In addition, three CPG islands in the region of miR-129-5p promoter were detected by bioinformatical prediction, and significantly higher expression of miR-129-5p and lower methylation level of miR-129-2 gene in OS cells treated with 5-Aza-2'-deoxycytidine (a potent DNA demethylating agent) than in those untreated cells were observed. Furthermore, lower migratory and invasive ability was found in cells with elevated miR-129-5p than in those with decreased miR-129-5p. These findings indicated that increased miR-129-5p may be mediated by demethylation and inhibit OS cell migration and invasion by targeting VCP in OS, and targeting miR-129-5p/VCP signaling pathway may serve as a therapeutic strategy for OS management, although further studies will be necessary.

Osteogenic Osteosarcoma of the Orbit: A Case Report

Osteogenic osteosarcomaof the orbitis a rareand aggressivetype of osteosarcoma. Head and neck osteosarcomas occur most commonly in the third and fourth decades and have equal sex predisposition. A 56 -year-old male patient was admitted to our clinic with proptosis on the left side and ptosis that had been present for five months. Ophthalmic examination revealed normal eye movements and vision. There was no pain and no paresthesia or any other significant com plaint or clinical finding. Magnetic resonance imaging studies showed a hyperintense, destructive extraconal mass lesion adjacent to the lateral wall invading retrobulber fat tissue of the left orbit. The patient underwent a lateral orbitotomy.Histopathological examination revealed osteogenic osteosarcoma of the orbit. Herein, we report a case with osteogenic osteosarcoma arising from the orbit is presented. The differential diagnoses of this tumor and the surgical results of radical resection are also pre sented.

Osteogenic tumors of bone

In this paper we provide an overview of benign and malignant osteogenic bone tumors. We describe the diagnostic features, radiographic findings, and pertinent ancillary studies needed to diagnose these bone-forming lesions. We begin with osteoid osteoma and osteoblastoma, which are histologically bland and eminently benign with rare possible exceptions. On the other end of the behavioral spectrum is osteosarcoma, which encompasses many subtypes ranging from high-grade osteogenic osteosarcoma to less overtly osteogenic lesions such as telangiectatic and small cell osteosarcoma. While classic osteogenic osteosarcoma can be easily recognized by its high grade morphology and formation of extracellular lace-like osteoid, its variants may pose diagnostic dilemmas as their differential diagnoses can include benign, fibrous, and vascular lesions, among others. Recognition of these variants is essential to avoid diagnostic pitfalls. In equivocal cases, some forms of osteosarcoma have shown molecular alterations that may prove diagnostically useful.

Abstract 1113: Role of the microRNA-23∼27∼24 clusters in osteosarcoma

Abstract Osteosarcomas are rare but aggressive tumors that predominantly affect adolescents. These neoplasms of mesenchymal origin are biologically heterogeneous and produce immature osteoid or bone. The pathogenesis of osteosarcomas is poorly understood although defective osteogenic differentiation seems to play a key role. In order to elucidate the underlying molecular mechanisms, 16 osteosarcoma cell lines, 2 osteoblast cell lines and 45 osteosarcoma tumors were studied using a combination of high-throughput techniques such as microRNA (miRNA) and gene expression profiling, miRNA sequencing and array comparative genomic hybridization. Overexpression of the miRNA clusters miR-23a∼27a∼24-2 (19p13.13) and miR-23b∼27b∼24-1 (9q22.32) was identified in a subset of the osteosarcoma tumors and cell lines. Furthermore, quantitative RT-PCR revealed that the miR-23a and miR-23b clusters were downregulated during osteoblast differentiation of the osteosarcoma cell line HOS and overexpression of these miRNAs (by transient transfection of miRNA mimics) delayed osteoblast differentiation and matrix mineralization evaluated by alkaline phosphatase and Alizarin Red staining. Target gene identification experiments were then performed for each of the members of the miR-23a and miR-23b clusters. Gain of function (using miRNA mimics for exogenous expression) and loss of function (using antisense miRNAs to inhibit endogenous expression) experiments followed by downstream gene expression analysis identified several putative targets in osteosarcoma cell lines HOS and HuO3N1. The gene lists were highly enriched in targets (including differentiation genes) identified by TargetScan and other target prediction software. These results suggest that deregulation of the miR-23∼27∼24 clusters may play a role in defective osteogenic differentiation and osteosarcoma. 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 1113. doi:1538-7445.AM2012-1113

Extraskeletal Osteosarcoma: Spectrum of Imaging Findings

The purpose of this article is to present the spectrum of imaging findings of primary and metastatic extraskeletal osteosarcoma and highlight the differences from primary osteogenic osteosarcoma in bone. Extraskeletal osteosarcoma is a rare mesenchymal malignancy of soft tissue, histologically indistinguishable from primary osteosarcoma of bone. However, there are distinct differences in demographics, imaging features, prognosis, and management compared with osteogenic osteosarcoma. Imaging characteristics reflect tumor morphology, with only 50% of primary tumors showing mineralization. Metastases may or may not show mineralization, even if present in the primary tumor. The overall prognosis is poor.

Abstract 719: Role of secreted frizzled-related proteins in inhibiting growth and invasion in human osteosarcoma

Abstract Aberrant activation of the canonical Wnt/β-catenin signaling pathway promotes osteosarcoma tumorigenesis and metastasis. Secreted frizzled-related proteins (SFRPs), a family of five glycoproteins (SFRP1-5), antagonize this pathway by competing with Frizzled receptors for Wnt ligands. Down-regulation of SFRPs through epigenetic silencing was commonly found in various malignancies. Specifically, in osteosarcoma, the loss of SFRP-3 expression has previously been observed in osteogenic sarcoma biopsy specimens and several osteosarcoma cells lines. Despite strong evidence of their status as tumor suppressors, the implication of SFRP-1, −2, −4 and −5 in the pathogenesis of osteosarcoma has yet been reported. The objective of this study, therefore, is to understand the role of SFRPs as Wnt antagonists and their functions in affecting key anti-cancer processes such as the suppression of growth and invasion, induction of apoptosis and cell cycle disruption, as well as down-regulation of various Wnt target oncogenes in osteosarcoma. In this study, we first performed western blot analysis and detected abundant levels of β-catenin protein in a panel of metastatic osteosarcoma cell lines, suggesting frequent activation of canonical Wnt/β-catenin signaling in osteosarcoma. Effective inhibitions of the Wnt/β-catenin pathway by restoration of SFRPs in U2OS cells were subsequently shown by marked suppression of both β-catenin/Tcf transcriptional activities and β-catenin protein using luciferase reporter assays and western blot analysis respectively. Immunofluorescence confocal microscopy analysis revealed an abnormal decrease in β-catenin accumulations in the nuclei and a corresponding increase in β-catenin localization to the cell membranes in U2OS cells over-expressing SFRPs. We next performed wound healing and Matrigel invasion assays and observed that ectopic expression of SFRPs significantly decreased osteosarcoma cell migration and invasion. Western blotting showed that the reduced U2OS cell invasion and migration correlated with the protein expression of matrix metalloproteinases-2 and −9. Furthermore, using MTT proliferation and colony formation assays, we found that restoration of SFRPs significant inhibited both anchorage-dependent and -independent growth in U2OS cells. These anti-proliferative effects were attributed to GO/G1 phase arrest in U2OS/SFRP-1, U2OS/SFRP-2 and U2OS/SFRP-5 cells and G2/M phase arrest in U2OS/SFRP-4 cells. At the same time, these anti-proliferative effects correlated with the suppression of major Wnt target oncogenes such as cyclin D1, c-Myc and survivin. Collectively, our findings strongly suggest that SFRPs may be exploited as a therapeutic target in the treatment of osteosarcoma. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 719.

Evaluation by Bone Scintigraphy of Osteogenic Activity of Commercial Bioceramics (Porous β-TCP and HAp Particles) Subcutaneously Implanted in Rats

Osteogenic potential of biomaterials used in bone regenerative therapy has been mainly examined in an animal-implantation study. We have here evaluated the applicability of bone scintigraphy in imaging ectopic bone formation, especially its initial phase, by beta-tricalcium phosphate (beta-TCP) particles that were implanted in rat dorsal subcutaneous tissues. In implanted osteogenic osteosarcoma cells used as a positive control, osteoid formation was found by histological examination and bone scintigraphy using (99m)Tc- hydroxymethyl diphosphonate (HMDP) at 2 and 3 weeks post-implantation, respectively, while the microfocuscomputed tomography (muCT) system required further mineralization, which occurred at 4 weeks. Implantation of beta-TCP particles alone induced only faint biomineralization inside the particles, which could be microscopically detected by calcein chelation at 2 weeks post-implantation, but not by other histological examinations (e.g., HE staining) or muCT. However, the bone scintigraphy successfully detected this microscopic change at 1 week. Implanted hydroxyapatite (HAp) particles alone used as a negative control did not induce mineralization at microscopic levels, and therefore nothing was detected by either calcein chelation or bone scintigraphy. In conclusion, the bone scintigraphic methodology, although exhibiting less quantitation and resolution, would be applicable as a non-invasive, highly sensitive methodology in detecting the initial, microscopic changes associated with mineralization.

Osteosarcoma of the Hand: A Rare Case for Radiographic Appearance, Location, and Age

Objective This case describes the history, process of correct diagnosis, and treatment of a patient with pain in her left fourth finger, later found to be an osteosarcoma. Clinical Features A 28-year-old woman presented with pain in her left fourth finger, which she also noticed had been “getting bigger.” Moderate tenderness and decreased range of motion were noticed over the metacarpophalangeal joint of the involved finger. Intervention and Outcome Initial radiographs indicated a benign tumor with a pathological fracture, and the patient was referred to a hand surgeon. After debridement of the area, the pathology report returned with a diagnosis of osteoblastic osteogenic osteosarcoma. The patient then underwent amputation of the fourth ray and chemotherapy. Conclusion This case presents a rare bone tumor of the hand and highlights the importance of clinical decision-making to lead to appropriate patient care.

Gene Expression of Osteoprotegerin Ligand, Osteoprotegerin, and Receptor Activator of NF-κB in Giant Cell Tumor of Bone: Possible Involvement in Tumor Cell-Induced Osteoclast-Like Cell Formation

Giant cell tumor of bone (GCT) is a rare primary osteolytic tumor of bone that is characterized by massive tissue destruction at the epiphysis of long bones. There is no evidence that tumor cells themselves are capable of bone destruction; instead, it appears that the tumor cells of GCT act by promoting osteoclastogenesis and, as a consequence, osteoclastic bone resorption. However, the mechanism by which this is achieved is not understood. Here we attempted to determine whether osteoprotegerin ligand (OPGL), the factor that is necessary and essential for osteoclastogenesis, is involved in tumor cell-recruited osteoclast-like giant cell formation in GCT. Using fluorescence in situ hybridization, we sought to determine mRNA expression of OPGL, its receptor RANK, and its decoy receptor OPG in three major cell types of GCT. We demonstrated that OPG mRNA was expressed in all three cell types of GCT, OPGL transcripts were mainly detected in spindle-shaped stromal-like tumor cells, whereas RANK was expressed only in macrophage-like mononuclear cells and multinuclear osteoclast-like giant cells. By semiquantitative RT-PCR, we also showed that the level of OPGL mRNA in GCT is much higher than that in normal bone and osteogenic osteosarcoma. In contrast, a similar level of OPG transcripts was detected in these three kinds of tissues, and RANK mRNA was detectable only in GCT tissues. We have further examined the regulation of gene expression of OPGL and OPG in tumor cells in response to osteotropic hormones. Administration of 1,25(OH)(2)D(3) and dexamethasone resulted in maximum up-regulation of OPGL level and down-regulation of OPG level in cultured GCT stromal-like tumor cells and the mouse bone marrow-derived ST-2 stromal cell line. Furthermore, we have shown that tumor cells of GCT induce differentiation of RANK-expressing myeloid RAW(264.7) cells into osteoclast-like cells in the presence of 1,25(OH)(2)D(3) and dexamethasone. Our findings suggest that OPGL is involved in the tumor cell-induced osteoclast-like cell formation in GCT. The ratio of OPGL/OPG by tumor cells may contribute to the degree of osteoclastogenesis and bone resorption.

Extraskeletal osteosarcoma of the scalp

A rare case of extraskeletal osteosarcoma of the scalp in a 56-year-old woman is described. At presentation she was found to have an 8-cm diameter, tender, firm, exophytic scalp tumor. MRI scan confirmed absence of underlying skeletal origin and showed extension along the subcutaneous plane. The tumor was excised and the patient received post-operative chemotherapy. Histologically, the tumor showed classical features of an osteogenic osteosarcoma with focal fibroblastic areas. In addition, there were rhabdoid cells present, which showed paranuclear cytoplasmic immunoreactivity for epithelial membrane antigen. The patient developed metastatic disease 6 months after surgical excision.

Multicentric randomized trials for high grade osteogenic osteosarcoma (OS). Cost-effectiveness?

Multicentric randomized trials for high grade osteogenic osteosarcoma (OS). Cost-effectiveness?