Extraskeletal Sites Research Articles

Endocultivation: continuous application of rhBMP-2 via mini-osmotic pumps to induce bone formation at extraskeletal sites

The continuous presence of recombinant human bone morphogenetic protein 2 (rhBMP-2) inside a scaffold may be crucial to the outcome in bone tissue engineering. This study investigated whether the release of the growth factor rhBMP-2 via different continuous application schemes influences histomorphological aspects of the hard and soft tissues induced. Three-dimensionally printed hydroxyapatite scaffolds were implanted into one latissimus dorsi muscle of 42 female Lewis rats. Simultaneously implanted mini-osmotic pumps were used to provide a continuous application of rhBMP-2 over 1, 2, or 4 weeks (total dose 200μg). A reference group received rhBMP-2 at the time of implantation only, and a control group received only block implantation. Bone density and histological examinations were performed after 8 weeks. No significant difference in bone density was found between the groups; however, the blood vessel count differed significantly between the groups receiving continuous treatments and both the control group and simultaneous rhBMP-2 treatment group (P<0.0001). Soft tissue types were distributed differently among the study groups. RhBMP-2 application via mini-osmotic pumps is as suitable for inducing bone formation as a single application at the time of implantation. The time interval over which rhBMP-2 was administered had no impact on the amount of new bone formation, probably due to the study duration and low local concentrations of growth factor.

Imaging Measurable (Minimal) Residual Disease in Multiple Myeloma

Purpose of Review The availability of effective anti-myeloma therapies has led to the concept of new response categories that define responses deeper than conventionally defined complete response (CR). In cases of CR, deepest response, defined as minimal residual disease (MRD)-negative status, has been independently associated with prolonged progression-free survival and overall survival. In spite of an unmeasurable MRD, most patients eventually relapse. Because current methodology using flow cytometry or gene sequencing focuses on sampling MRD primarily from bone marrow, the low-level disease that may be present at other places in the skeleton and/or at extra-skeletal sites could be ultimately responsible for clinical relapse. Relevantly, sensitive imaging has the potential to complement MRD assessment by providing a complete picture of the entire bone/bone marrow compartment and extramedullary sites.

Osteoclasts and Remodeling Based Bone Formation.

Osteoclasts are multinuclear cells of the monocyte macrophage lineage. They are responsible for bone remodeling by first resorbing packets of bone, which are subsequently replaced by new bone produced by osteoblasts. Osteoblasts are derived from mesenchymal stem cells, and thus osteogenesis can also be induced in various tissues at extra skeletal sites. Fifty years ago it was discovered that demineralized bone matrix is able to induce ectopic bone formation. Since that time the differentiation of bone cells has been studied intensively. The aim was to produce bone for the repair of bone defects. The molecular basis of bone remodeling has been established in great detail and the mechanism of how bone resorption and bone formation are coupled in bone remodeling sites has been delineated. Osteoclasts resorb bone, but they also secrete anabolic signals that induce mesenchymal stem cells and osteoblasts to initiate osteogenesis in resorption lacuna (remodeling) or another nonresorbed site (modeling). It is this osteoclast derived influence on mesenchymal stem cells and osteoblasts that could be utilized in tissue engineering. So far investigators have tried to find ways to induce bone formation by activating mesenchymal stem cells, but a better understanding of the remodeling paradigm of bone, the intrinsic regulation of bone formation through osteoclastic resorption, could be utilized for tissue engineering. Scaffold materials like decellularized natural tissue extracellular matrices or bone type resorbable mineral matrices induce resorption and simultaneously induce bone formation.

Heterotopic Ossification: A Review of Current Understanding, Treatment, and Future.

Heterotopic ossification is the formation of bone at extraskeletal sites. The incidence of heterotopic ossification in military amputees from recent operations in Iraq and Afghanistan has been demonstrated to be as high as 65%. Heterotopic ossification poses problems to wound healing, rehabilitation, and prosthetic fitting. This article details the current evidence regarding its etiology, prevention, management, and research strategies.

Pancreatic involvement by mesenchymal chondrosarcoma harboring the HEY1-NCOA2 gene fusion

Mesenchymal chondrosarcoma (MC) is an aggressive small, round, blue cell tumor with chondrogenic differentiation that typically arises in bony sites. Approximately, a third of these tumors develop in extraskeletal sites such as the meninges, and somatic soft tissue. The MCs are well-circumscribed, lobulated masses, with focal calcification. Histologically, 2 distinct populations of neoplastic cells characterize MC: sheets of primitive small, round, blue cells surrounding islands of well-developed hyaline cartilage with mature chondrocytes in lacunae. Involvement of the gastrointestinal tract and pancreas by primary or metastatic MC is a relatively rare occurrence. We identified 8 patients with MC in our departmental archives from 1990 to 2015, two of which had pancreatic involvement. The patients were young women who developed masses in the distal pancreas. Molecular testing demonstrated that both tumors harbored the recently described HEY1-NCOA2 gene fusion. These cases illustrate that pancreatic involvement can occur in MC, and the demonstration of HEY1-NCOA2 fusion can be helpful to confirm the diagnosis.

Novel ERα positive breast cancer model with estrogen independent growth in the bone microenvironment.

Despite successful therapeutic options for estrogen receptor-α (ERα)+ breast cancer, resistance to endocrine therapy frequently occurs leading to tumor recurrence. In addition to intrinsic changes in the cancer cells, herein we demonstrate that tumor cell-microenvironment interactions can drive recurrence at specific sites. By using two ERα+ cell lines derived from spontaneous mammary carcinomas in STAT1−/− mice (SSM2, SSM3), we establish that the bone microenvironment offers growth advantage over primary site or lung in the absence of ovarian hormones. While SSM3 did not engraft at primary and skeletal locations in the absence of estrogen, SSM2 selectively grew in bone of ovariectomized mice and following administration of aromatase inhibitors. However, SSM2 growth remained hormone-dependent at extraskeletal sites. Unexpectedly, bone-residing SSM2 cells retained ERα expression and JAK2/STAT3 activation regardless of the hormonal status. These data position the bone microenvironment as a unique site for acquisition of tumor/estrogen independency and identify the first ERα+ hormone-independent tumor model in immunocompetent mice.

Two cases of canine liposarcomas: an uncommon tumour

Liposarcomas are rare malignant tumors of adipose tissues with overall incidence of 0.2–0.5% among all the canine neoplasms. They may originate either from bone marrow or extra skeletal sites such as adipose tissues. Histological classification include well differentiated, pleomorphic, and myxoid subtypes. Clinical cytological, gross pathological and histopathological features of two extra skeletal canine liposarcoma cases presented to the Veterinary Teaching Hospital (VTH), University of Peradeniya are described here.

Osteogenic gene array of osteoblasts cultured on a novel osteoinductive biphasic calcium phosphate bone grafting material.

Recently, novel biphasic calcium phosphate (BCP) scaffolds have emerged as a new class of bone grafts with osteoinductive potential demonstrating the ability to form ectopic bone in extra-skeletal sites. The aim of the present study was to perform an osteogenic gene array to target possible genes responsible for eliciting the changes in cell expression responsible for inducing osteoblast differentiation. Human MG63 osteoblast-like cells were seeded for 24h on tissue culture plastic or osteoinductive BCP particles and analyzed for upregulated genes using an osteogenesis super-array. Osteoblast-related genes including those transcribed during bone mineralization, bone metabolism, cell growth and differentiation, as well as gene products representing extracellular matrix molecules, transcription factors, and cell adhesion molecules were investigated. An upregulation of genes transcribing biglycan (1.7-fold), bone morphogenetic proteins 1, 2, 4, 6, and 7 (1.5-2.1-fold), various collagen isoforms including 1a1, 1a2, 2a1, and 5a1 (1.73-2.72-fold), colony stimulating factor 2 (2.59-fold), fibroblast growth factor receptor 2 (1.79-fold), fibronectin (2.56-fold), integrin alpha 1, 2, and 3 (1.82-2.24-fold), SOX9 (2.75-fold), transforming growth factor beta receptor 2 (1.72-fold), vitamin D (1.89-fold), and vascular endothelial growth factor A and B (2.00, 1.75-fold) were all significantly (p<0.05) increased on BCP particles when compared to control tissue culture plastic. In summary, a number of activated genes were involved in bone formation following osteoblast attachment to BCP particles. The involvement of key chondrogenic genes hints that bone grafts capable of spontaneously inducing ectopic bone formation may implicate endochondral ossification. Further investigations in the triggered pathways involved in the process of ectopic bone formation are necessary to understand the key inductive properties of these novel osteoinductive BCP particles. Novel osteoinductive BCP particles demonstrate a wide range of significant increases over several key molecules implicated in osteogenesis that may be implicated in their ability to form ectopic bone formation.

Imaging response during therapy (tx) with radium-223 (Ra-223) for castrate resistant prostate cancer (CRPC) with bone metastases (BM).

282 Background: Ra-223 is an alpha emitter that selectively targets BM. It was shown to improve the survival of patients (pts) with CRPC and BM, and thus is approved as a standard tx for these pts. However, the imaging response during Ra-223 tx is poorly defined. We aimed to describe the imaging response in pts with CRPC and BM treated with Ra-223. Methods: We evaluated the CT and bone scans response among pts with CRPC and BM, who were treated with Ra-223. Tx consisted of an injection administered q 4 weeks up to 6 injections. Scans were done at baseline, after 3 injections, and upon completion of 6 injections. Logistic regression model was used to analyze clinicopathologic factors associated with scans response. Results: 51 pts were included (median age 72). 59% (n = 30) were treated post docetaxel chemotherapy. 47% (n = 24) were treated concomitantly with a systemic standard therapy (e.g enzalutamide or abiraterone). 76% (n = 39) completed the planned 6 injections. A clinical benefit (improvement of skeletal pain and performace status) was noted in 67% (n = 34). 53% (n = 27) had a decrease of alkaline phosphatase. The response of bone metastatic disease (number of lesions) at 3 months was improvement in 22% (n = 11), stable in 53% (n = 27), and progression in 25% (n = 13). 1/13 (8%) pts evaluated at 6 months, had a progression of BM versus the 3 months status. Progression (RECIST ) of extraskeletal sites (lymph nodes, lungs, liver, adrenal) at 3 months was noted in 35% (n = 18). Concurrent systemic standard therapy (e.g enzalutamide or abiraterone) (OR 3.3, p = 0.04), Pre-tx PSADT ≥ 3 months (OR 2.62, p = 0.02) and on treatment stable/decreasing LDH (OR 2.9, p = 0.05) were associated with on treatment stable extraskeletal metastatic disease. Conclusions: Progression of BM during Ra-223 was uncommon. A bone flare may be noted during the first 3 months, and should not be confused with BM progression. Clinician should consider repeating a CT scan at 3 months in pts with short pre-tx PSADT, and LDH increase during tx, to exclude extraskeletal metastatic disease progression.

A rare case of extraskeletal Ewing's sarcoma/primitive neuroectodermal tumor developing in maxillary sinus of an old patient

Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) family of tumors is an uncommon group of malignant neoplasms that may present in both skeletal and extraskeletal sites. PNET outside the central nervous system is called peripheral PNET (pPNET) developing from migrating embryonal cells of the neural crest. Very few cases of pPNET of the maxilla are reported in English literature. These tumors may be difficult to diagnose due to their primitive morphology. These tumors occur predominantly in infancy or early childhood. The occurrence of extraskeletal ES/PNET in the maxillary sinus in an old age is very rare. We report a case of extraskeletal ES/PNET developing in maxillary sinus in a 60-year-old woman. The ES/PNET should be included in the differential diagnosis of a small round cell tumor and immunohistochemical analysis with a panel of immunomarkers should be done for correct diagnosis and proper treatment.

Bone-formers and bone-losers in an archaeological population.

ABSTRACTObjectivesRecent biomedical research suggests that, in modern human populations, individuals may vary in their inherent tendency toward bone formation at skeletal and extra‐skeletal locations. However, the nature of this phenomenon is incompletely understood, and the extent to which it might apply to past populations is unclear. It is hypothesized that if there is inter‐individual variation in some overall tendency toward bone formation in skeletal and extra‐skeletal sites then there should be a positive relationship between ligamentous ossification and thickness of cortical bone. This work is a test of this hypothesis in an archaeological population.Materials and MethodsThe study material comprises adult skeletons (N = 137 individuals) of documented age at death from 18th to 19th century London. It examines the relationship between bone deposition in the anterior longitudinal ligament (ALL) in the thoracic spine and cortical index (CI) at the metacarpal measured by radiogrammetry.ResultsControlling for the potential confounders age, sex, skeletal completeness, occupation (males) and parity (females), there was a positive association between ossification into the ALL and CI. This reflects lesser medullary cavity width in those showing ALL ossification.DiscussionLigamentous ossification in the axial skeleton and peripheral cortical bone status are linked, individuals with ALL ossification showing lesser resorption of cortical bone at the endosteal surface. This is consistent with the idea of inter‐individual variation in some general bone‐forming/bone‐losing tendency in this 200 year old study population, but there was no evidence of a link between ALL ossification and increased skeletal subperiosteal bone deposition. Am J Phys Anthropol 159:577–584, 2016. © 2015 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.

Posterior mini-incision total hip arthroplasty controls the extent of post-operative formation of heterotopic ossification.

Heterotopic ossification (HO) is the formation of bone at extra-skeletal sites. Reported rates of HO after hip arthroplasty range from 8 to 90 %; however, it is only severe cases that cause problems clinically, such as joint stiffness. The effects of surgical-related controllable intra-operative risk factors for the formation of HO were investigated. Data examined included gender, age of patient, fat depth, length of operation, incision length, prosthetic fixation method, the use of pulsed lavage and canal brush, and component size and material. All cases were performed by the same surgeon using the posterior approach. A total of 510 cases of hip arthroplasty were included, with an overall rate of HO of 10.2 %. Longer-lasting operations resulted in higher grades of HO (p = 0.047). Incisions >10 cm resulted in more widespread HO formation (p = 0.021). No further correlations were seen between HO formation and fat depth, blood loss, instrumentation, fixation methods or prosthesis material. The mini-incision approach is comparable to the standard approach in the aetiology of HO formation, and whilst the rate of HO may not be controllable, a posterior mini-incision approach can limit its extent.

Endocultivation: Histomorphological effects of repetitive rhBMP-2 application into prefabricated hydroxyapatite scaffolds at extraskeletal sites

The timing of application of recombinant human bone morphogenic protein-2 (rhBMP-2) may be important in determining the final outcome of engineered bone tissue. This study investigates the impact of repetitive rhBMP-2 application on hard and soft tissue morphology in endocultivation.A 3D-printed scaffold was implanted into a pouch in the latissimus dorsi muscle in 40 Lewis rats. RhBMP-2 was injected at defined time points and animals received a total of 200 μg each. Control groups received either rhBMP-2 simultaneously with scaffold implantation, or solely a scaffold with no rhBMP-2. Fluorescence markers were injected after operation. CT-scans and histological examination were performed after 8 weeks.Multiple comparisons revealed significant differences of bone density between the groups who received delayed injections at two separate time points in time compared to those who had simultaneous rhBMP-2 application (p = 0.0038; p = 0.0063) and the control group (p = 0.017, p = 0.0284). The blood vessel count was significantly higher in groups with repetitive injections compared with both control groups. Two soft tissue types were identified and found to have different distributions in the different study groups. Fluorescence labeling showed active new bone formation after 4–5 weeks in all groups where rhBMP-2 was administered.Multiple repetitive injections were more effective than simultaneous application regarding bone density indicating time-dependent effects of rhBMP-2. Bone formation processes were detectable several weeks after rhBMP-2 application indicating long-term effects.

Effectiveness of two novel anionic and cationic platinum complexes in the treatment of osteosarcoma.

This study aimed to characterize the cellular basis of the platinum cytotoxicity of two novel platinum complexes, 3Pt and 1Pt, in comparison with that of cisplatin. 3Pt comprises anionic phosphate moieties, while 1Pt comprises neutral aromatic ligands. We compared the cytotoxic potency of 3Pt and 1Pt with that of cisplatin in osteosarcoma cell lines and an orthotopic mouse model. The cytotoxic potency of 3Pt was markedly higher than that of cisplatin in all cell lines. Both novel platinum complexes showed a complete lack of cross resistance in cisplatin-resistant cells. Caffeine enhanced the cytotoxic potency of these novel platinum complexes, as observed for cisplatin. Apoptosis after drug administration was observed by DNA ladder formation and an annexin V/PI assay. DNA double-strand breaks were confirmed by phosphorylation of histone H2AX. In vivo, the antitumor activity of 3Pt and 1Pt was superior and similar, respectively, to that of cisplatin. Both novel platinum complexes exerted strong antitumor effects on osteosarcoma in vitro and in vivo. 3Pt may be an effective drug for the treatment of bone cancer because the PO3 moiety has a high affinity to bone, as exhibited by bisphosphonates, and is expected to decrease the incidence of side effects at extraskeletal sites and overcome drug resistance. Cationic 1Pt may also be an effective antitumor drug because of its unique chemical structure and properties. Further investigations to detail the antitumor effects of these ionic Pt complexes on osteosarcoma are warranted.

Heterotopic ossification in victims of the London 7/7 bombings

Heterotopic ossification (HO) is the formation of bone at extraskeletal sites. Over 60% of amputees injured by improvised explosive devices in the recent conflict in Afghanistan have developed HO, resulting...

Primary spinal intradural mesenchymal chondrosarcoma with detection of fusion gene HEY1-NCOA2: A paediatric case report and review of the literature

Mesenchymal chondrosarcoma is an extremely rare malignant tumour that most commonly originates in the bone, but is also present in extraskeletal sites. The tumour is morphologically characterized by a biphasic pattern of small round cells and islands of cartilage. Spinal mesenchymal chondrosarcomas are even rarer and, therefore, few investigations exist regarding the biological behaviour of the tumours. In the present study, we report a case of a 10-year-old female presenting with 9 months of back pain and radiographic findings of an intradural lesion measuring 1.5 cm at the level of Th4. The tumour was completely excised and subjected to pathological analyses. Following detection of the HEY1-NCOA2 fusion gene, the tumour was morphologically and immunohistochemically defined as an intradural mesenchymal chondrosarcoma attached to the dura mater. In this study, we validate the recent identification of the fusion gene HEY1-NCOA2 in paediatric extraskeletal mesenchymal chondrosarcomas. The relevant literature is reviewed and further discussed in relation to our findings.

A Rare Case of Congenital Ewing Sarcoma/PNET of the Scapula

Ewing sarcoma (ES)/primitive neuroectodermal tumors (PNET) are known to occur at both central and peripheral locations, as well as at skeletal and extraskeletal sites. They most commonly occur in the first 2 decades of life. We report a rare case of congenital Ewing sarcoma/primitive neuroectodermal tumor arising from the scapula.

Undifferentiated Pancreatic Carcinoma with Osteoclast-Like Giant Cells: a Case Report

Undifferentiated pancreatic carcinoma with osteoclast-like giant cells (UPC-OGCs) is a rare neoplasm with frequency of 0.2 % of reported pancreatic carcinomas [1]. Tumors with osteoclast-like giant cells have rarely been reported in a variety of extra-skeletal sites. On the alimentary tract, the pancreas is the most concerned [2, 3]. A number of terms have been used to describe variants of undifferentiated pancreatic carcinoma, especially pleomorphic carcinoma, pleomorphic giant cell carcinoma, sarcomatoid carcinoma, spindle cell carcinoma, anaplastic carcinoma, undifferentiated carcinoma, and osteoclastic or pleomorphic giant cell tumors [4]. Histologically, the tumor combines two main cell populations, a malignant mononuclear cells population and the scattered nonneoplastic osteoclast-like giant cells [3, 5]. Since the first description by Rosai in 1968 [6], there have been only a few cases reported in the world literature. Our aim is to describe a new case of undifferentiated carcinoma of the pancreas with osteoclast-like giant cells which was early diagnosed, with a review of literature.

Aggressive clinical course of epithelioid angiosarcoma in the femur: a case report

BackgroundEpithelioid angiosarcoma is a rare variant of angiosarcoma, and is characterized by an epithelioid morphologic appearance that mimics carcinoma. These tumors usually arise in extraskeletal sites; origination in bone is rare.Case presentationA 69-year-old woman presented with right knee pain. Plain radiographs and magnetic resonance imaging showed an osteolytic lesion with a large soft-tissue extension into the distal femur. Under a diagnosis of metastatic carcinoma of unknown origin based on the biopsy specimen, resection and replacement with an artificial joint were performed. Histologic analysis of the resected material confirmed epithelioid angiosarcoma, supported by immunoexpression of cytokeratins and vascular markers. Three months after surgery, metastasis to the bone and lymph nodes was observed, and the patient died of the disease shortly thereafter.DiscussionEpithelioid angiosarcoma of bone is characterized by an aggressive clinical course. A possibility of epithelioid angiosarcoma of bone should be considered in cases with such epithelial features, particularly if only small specimens are available.

Radiographic characteristics of the hand and cervical spine in fibrodysplasia ossificans progressiva.

Fibrodysplasia ossificans progressiva (FOP) is a disabling heritable disorder of connective tissue characterized by progressive heterotopic ossification in various extraskeletal sites. Early correct diagnosis of FOP is important to prevent additional iatrogenic harm or trauma. Congenital malformation of the great toes is a well-known diagnostic clue, but some patients show normal-appearing great toes. The thumb shortening and cervical spine abnormalities are other skeletal features often observed in FOP. This study aimed to address the quantitative assessment of these features in a cohort of patients with FOP, which potentially helps early diagnosis of FOP. Radiographs of the hand and cervical spine were retrospectively analyzed from a total of 18 FOP patients (9 males and 9 females) with an average age of 13.9 years (range 0.7-39.3 years). The elevated ratio of the second metacarpal bone to the distal phalanx of the thumb (> +1SD) was a consistent finding irrespective of the patient's age and gender. Infant FOP patients, in addition, exhibited an extremely high ratio of the second metacarpal bone to the first metacarpal bone (> +3SD). The height/depth ratio of the C5 vertebra increased in patients over 4 years of age (> +2SD). Additionally, the ratio of (height+depth) of the C5 spinous process to the C5 vertebral depth was markedly elevated in young patients (> +2SD). We quantitatively demonstrated the hand and cervical spine characteristics of FOP. These findings, which can be seen from early infancy, could be useful for early diagnosis of FOP even in patients without great toe abnormalities.