Giant cell tumor of bone: treatment and outcome of 214 cases

Coagulação por plasma de argônio como adjuvante à curetagem estendida em tumores de células gigantes do osso: Um estudo de 50 casos

Objetivo A curetagem estendida com adjuvantes de tumores de células gigantes do osso está associada a uma menor taxa de recidiva da neoplasia e à preservação da articulação adjacente. Este estudo foi feito para estimar a taxa de recidiva e o resultado funcional após o uso de plasma de argônio como adjuvante à curetagem estendida.

Métodos Cinquenta pacientes com tumores de células gigantes que atendiam a todos os critérios de inclusão foram selecionados para o estudo e submetidos à curetagem estendida com broca de alta velocidade e fotocoagulação com plasma de argônio entre julho de 2016 e janeiro de 2019. À consulta de acompanhamento, os pacientes foram avaliados quanto a quaisquer queixas de dor e sinais como sensibilidade, aumento local da temperatura e diminuição da amplitude de movimento da articulação adjacente. Radiologicamente, os pacientes foram avaliados quanto à presença de qualquer aumento de radiotransparência ao redor do manto de cimento e incorporação do enxerto subarticular. O questionário Musculoskeletal Tumor Society Score (MSTS) foi administrado aos pacientes e a amplitude de movimentação da articulação adjacente foi comparada à articulação contralateral.

Resultados Quatro pacientes apresentaram recidiva, o que corresponde a uma taxa de 8%. Seis meses após a cirurgia, 26 de 28 pacientes com tumor no membro inferior tinham capacidade de sustentação de peso de grau 5 e amplitude de movimento comparável à articulação saudável contralateral, com pontuação MSTS média de 27 (intervalo de 18 a 30).

Conclusão A curetagem estendida de tumores de células gigantes com coagulação por plasma de argônio está associada a baixas taxas de recidiva da neoplasia; é uma modalidade eficaz no tratamento desses tumores e o resultado funcional é comparável ao do membro saudável.

A Rationale for the Activity of Bone Target Therapy and Tyrosine Kinase Inhibitor Combination in Giant Cell Tumor of Bone and Desmoplastic Fibroma: Translational Evidences

Giant cell tumor of bone (GCTB) and desmoplastic fibroma (DF) are bone sarcomas with intermediate malignant behavior and unpredictable prognosis. These locally aggressive neoplasms exhibit a predilection for the long bone or mandible of young adults, causing a severe bone resorption. In particular, the tumor stromal cells of these lesions are responsible for the recruiting of multinucleated giant cells which ultimately lead to bone disruption. In this regard, the underlying pathological mechanism of osteoclastogenesis processes in GCTB and DF is still poorly understood. Although current therapeutic strategy involves surgery, radiotherapy and chemotherapy, the benefit of the latter is still debated. Thus, in order to shed light on these poorly investigated diseases, we focused on the molecular biology of GCTB and DF. The expression of bone-vicious-cycle- and neoangiogenesis-related genes was investigated. Moreover, combining patient-derived primary cultures with 2D and 3D culture platforms, we investigated the role of denosumab and levantinib in these diseases. The results showed the upregulation of RANK-L, RANK, OPN, CXCR4, RUNX2 and FLT1 and the downregulation of OPG and CXCL12 genes, underlining their involvement and promising role in these neoplasms. Furthermore, in vitro analyses provided evidence for suggesting the combination of denosumab and lenvatinib as a promising therapeutic strategy in GCTB and DF compared to monoregimen chemotherapy. Furthermore, in vivo zebrafish analyses corroborated the obtained data. Finally, the clinical observation of retrospectively enrolled patients confirmed the usefulness of the reported results. In conclusion, here we report for the first time a molecular and pharmacological investigation of GCTB and DF combining the use of translational and clinical data. Taken together, these results represent a starting point for further analyses aimed at improving GCTB and DF management.

Giant Cell Tumor of Bone: A Single Center Study of 115 cases

•

Giant cell tumor of bone (GCTB) is a rarely metastasizing, locally aggressive tumor.

•

GCTB recurs frequently after intralesional curettage.

•

Denosumab is a potential neoadjuvant treatment option for borderline resectable lesions.

Background

Giant cell tumor of bone (GCTB) is a locally aggressive bone tumor that represents about 4–5% of all primary bone tumors. It is characterized by aggressive growth, possible recurrence after surgical treatment and, in rare cases, metastasis. Surgical management is the primary treatment and may include intralesional curettage with adjuvants or, in rare cases, wide resection. In recent years the monoclonal antibody denosumab has been introduced as a potential (neo-)adjuvant systemic treatment option for patients with borderline resectable or unresectable lesions. Currently several studies reported that the use of denosumab prior to curettage possibly increase the risk of local recurrence.

Methods

In this retrospective study we reviewed 115 cases of GCT with a mean follow-up of 65.6 (24–404) months who underwent a surgical treatment with or without preoperative denosumab therapy in our institution. Potential risk factors for LR and complications were analyzed.

Results

The study includes 47 male (40.9%) and 68 female (59.1%) patients with a mean age of 33.9 (10–77) years and a mean follow-up of 65.6 (24–404) months. Denosumab was used in 33 (28.7%) cases, in 14 cases (12.2%) in a neoadjuvant setting and in 17 cases preoperatively before re-curettage (14.8%) after LR. In 105 cases (91.3%) an intralesional curettage was performed. The overall LR rate was 47.8% (55 cases). Patients who underwent intralesional curettage and bone cement augmentation without neoadjuvant denosumab treatment had LR in 42.2% (38/90) of the cases. Patients who underwent neoadjuvant denosumab treatment prior to curettage had LR in 28.6% (4/14). Re-recurrence was frequent in patients with neoadjuvant denosumab treatment who had LR after initial curettage (50%, 8/16). After wide resection and endoprosthetic replacement one case (20%) of local recurrence was detectable (1/5 cases).

Conclusions

GCTB recurs frequently after intralesional curettage and cement augmentation. While denosumab is a potential (neo-)adjuvant treatment option that might be used for lesions that are difficult to resect, surgeons should be aware that LR is still frequent.

Scanning Electron Microscopy of Giant Cells from Giant Cell Tumor of Bone

Surface ultrastructures of giant cells (GCs) may help distinguish an aggressive tumor from an indolent giant cell tumor (GCT). This protocol describes a better way for ultrastructural surface imaging of GC from GCT of bone by scanning electron microscope (SEM). Fresh GCT samples collected in Dulbecco's modified Eagle medium (DMEM) are thoroughly washed to remove the blood and treated with collagenase to isolate the GCs. The collagenase-treated and critical point dried (CPD) samples yield a greater number of isolated GCs with better surface morphology, including membrane folding and micro-vesicular structures on the surface. Collagenase digestion and CPD should be performed for ultrastructural surface imaging of individual giant cells.

Denosumab Does Not Decrease Local Recurrence in Giant Cell Tumor of Bone Treated With En Bloc Resection

We performed a systematic analysis of existing studies to determine whether preoperative denosumab reduces the risk of local recurrence for patients with giant cell tumor of bone treated with en bloc resection and to address the optimal duration of preoperative denosumab with respect to the risk of local recurrence after en bloc resection. Denosumab did not decrease the risk of local recurrence after en bloc resection; the proportion of patients with local recurrence was 3.6% (2 of 56) in the en bloc resection with preoperative denosumab group vs 14.2% (40 of 280) in the en bloc resection alone group, with an overall pooled odds ratio of 0.76 (P=.67). Meta-regression models revealed no association between the duration of preoperative denosumab and the odds of local recurrence after en bloc resection (P=.83). Administration of denosumab for 3 months before en bloc resection is appropriate for sufficient bone hardening to reduce tumor cell spillage and does not result in denosumab-related complications. [Orthopedics. 2021;44(6):326-332.].

Cytodiagnosis of giant cell tumour presenting at unusual age and site with review of literature

Giant cell tumour (GCT), also known as osteoclastoma, is an osteolytic tumour. It involves the epiphyseal and metaphyseal regions of long bones in adults. On rare occasions, these may occur in paediatric patients, and may involve uncommon locations such as the sternum, pelvis and, particularly infrequently, rib bones. We present a rare case of GCT in the rib of a child, diagnosed on fine needle aspiration.

Establishment and characterization of the NCC-GCTB4-C1 cell line: a novel patient-derived cell line from giant cell tumor of bone

Giant cell tumor of bone (GCTB) is a rare osteolytic intermediate bone tumor that harbors a pathogenic H3F3A gene mutation and exhibits characteristic histology. The standard curative treatment for GCTB is complete surgical resection, but it frequently results in local recurrence and, more rarely, metastasis. Therefore, effective multidisciplinary treatment is needed. Although patient-derived tumor cell lines are promising tools for preclinical and basic research, there are only four available cell lines for GCTB in public cell banks. Thus, the aim of this study was to establish a novel GCTB cell line. Using surgically resected tumor tissues from a patient with GCTB, we established a cell line named NCC-GCTB4-C1. The cells harbored the typical H3F3A gene mutation and exhibited constant proliferation and invasive capabilities. After characterizing NCC-GCTB4-C1 cell behaviors, we conducted high-throughput screening of 214 anti-tumor drugs and identified seven effective drugs. Comparing the results of high-throughput screening using NCC-GCTB4-C1 cell line with the results using NCC-GCTB1-C1, NCC-GCTB2-C1, and NCC-GCTB3-C1 cell lines that we previously established, four drugs were in common effective. This study showed potential drugs for the treatment of GCTB. These data indicate that NCC-GCTB4-C1 has the potential to be a powerful tool in preclinical and basic research on GCTB.

Extended Curettage for Giant Cell Tumors of Bone: A Surgeon's View

The key to intralesional surgical treatment of giant cell tumor of bone (GCTB) is extended curettage. As GCTB is locally aggressive with a high propensity for local recurrence, a primary factor of surgical treatment is the ability to achieve local tumor clearance. GCTB commonly affects the epimetaphyseal region of the bone, which may compromise the integrity of the articular surface. With the exception of expendable bone that may be considered for resection without the challenge of reconstruction (e.g., the proximal aspect of the fibula or the distal aspect of the ulna), a large majority of cases of GCTB can be treated with joint-preserving techniques. In the present article, we share a video demonstration including the surgeon view of intralesional surgery for GCTB, with emphasis on the 360° visualization of the tumor cavity, dilemmas regarding use of adjuvants for extended curettage, and options in cavity reconstruction.

Description

The surgical procedure involves 4 essential components.(1) Surgical exposure and isolation of the soft tissues. The technique begins with a complete exposure that allows visualization of the entire tumor cavity. The initial part of the exposure involves getting to the bone and to the soft-tissue mass outside the bone, when present. The muscles are separated from the bone and retracted away from the soft-tissue component of the tumor. Soft tissue is adequately retracted to allow complete visualization of the tumor cavity. The tissues around the cavity are protected by placing hydrogen peroxide-soaked mops around the tumor cavity. The aim is to isolate the bone opening and avoid any contamination of soft tissue by the tumor, as hydrogen peroxide kills GCTB cells on contact¹. The soft-tissue mass of the tumor is removed en bloc with a cover of normal tissue in order to prevent spillage into uninvolved tissues. Ward and Li advise the use of cautery for this part of the exposure in order to minimize contamination because high-temperature cautery kills the tumor². The initial opening into the osseous tumor cavity is made smaller in order to control the tumor spillage, and then enlarged in order to gain complete visualization.(2) Curetting and burring for tumor clearance. The walls are curetted, using the sharp edges of the curet. Good visualization is the key to meticulous and complete curetting. We recommend the use of a surgical loupe and headlight for adequate visualization¹. Tumor cavities often have overhanging osseous ridges with tumor hidden behind them. A curet may not be useful for breaking these hard osseous ridges; a burr is best utilized for this task. In addition to breaking the ridges, a high-speed burr helps to extend the curettage for a few millimeters beyond the grossly visible tumor margin^3,4.(3) Use of adjuvants to achieve extended curettage. Various physical and chemical agents have been utilized to control the microscopic disease remaining in the walls following a thorough curettage. Liquid nitrogen, phenol, hydrogen peroxide, alcohol, electrocautery, bone cement, and argon plasma cautery have been utilized as adjuvants. Balke et al. showed that the rate of recurrence decreases with use of more adjuvants, with high-speed burring having the greatest effect on the rate of recurrence, likely as a result of the larger resection and the thermal effect of the burring⁵. We suggest a case-by-case use of specific adjuvants, but in our experience, a high-speed burr is always utilized, hydrogen peroxide is utilized commonly when safe, and argon-plasma cautery is utilized judiciously.(4) Reconstruction of the cavity. The defect may be filled with bone, cement, or a combination of both. We suggest an individual, case-by-case approach to the reconstruction. In cases in which >25% of the articular surface is undermined², subchondral bone grafting is recommended prior to cementing (i.e., a sandwich procedure).

Alternatives

GCTB requires tumor clearance for local control. One alternative to intralesional surgical treatment performed around the knee is resection of the tumor-affected segment of bone and reconstruction with an endoprosthesis. This is a joint-sacrificing alternative and, in our experience, should be reserved for patients with joint involvement, multiply recurrent disease, or insufficient remaining wall to curet.

Rationale

When adequate tumor clearance is possible, joint-salvaging intralesional surgical treatment remains the superior option to achieve physiological joint function⁶. Indications for this procedure include maintained or restorable joint congruity and construct stability allowing early mobilization.

Expected Outcomes

The rate of local recurrence following intralesional surgical treatment ranges from 16% to 25%^1,7. The use of a high-speed burr is an essential part of the curettage⁵, and hydrogen peroxide is a safe choice for an adjuvant, if desired and when suitable, to provide greater local control⁸. Reconstruction with bone, cement, or both is acceptable, but we recommend building up a few millimeters of subchondral bone with bone graft before cement filling^1,9.

Important Tips

Illumination and magnification within the tumor cavity provide better visualization.Isolation of the soft tissue around the tumor with use of hydrogen peroxide-soaked mops can prevent seeding and contamination.Meticulous tumor clearance is more important to minimize recurrence than the use of adjuvants.Use of a C-arm helps to better guide extension of the curettage and avoid inadvertent joint penetration.Maintaining joint congruity is essential.

Giant cell tumor of the cervical spine treated by carbon ion radiotherapy: A case report

INTRODUCTION

Giant cell tumor (GCT) of the bone is a benign-malignant intermediate tumor with locally destructive growth and a relatively high local recurrence rate. Neurological symptoms may develop in patients with GCT of the spine, and surgical treatment is prioritized in cases where resection is possible. However, the local recurrence rate of GCT of the bone is higher than that of GCT at other sites owing to the associated surgical challenges, and treatment is often difficult. No study to date has reported long-term remission of recurrent tumors for more than 5 years by treatment with carbon ion beam radiotherapy after resection of GCT of the cervical spine.

PATIENT CONCERNS

A 14-year-old boy who experienced recurrence after surgery for GCT of the cervical spine.

DIAGNOSIS

The patient presented with cervical pain, and computed tomography revealed a mass of the C2 vertebral body. He underwent surgery for tumor resection and autologous bone grafting, and the final pathological diagnosis was GCT. The transplanted bone exhibited gradual progression of resorption, and recurrent tumors were observed on computed tomography and magnetic resonance imaging 1 year and 4 months after surgery.

INTERVENTIONS

The patient was started on denosumab at 15 years of age and received carbon ion beam therapy with 70.4 Gy administered in 32 sessions over 7 weeks.

OUTCOMES

No progressive tumor growth was observed, there were no neurological symptoms such as paralysis or pain were noted, and the patient was in remission for 5 years after irradiation.

CONCLUSION

These findings suggest that carbon ion radiotherapy is a safe and effective therapeutic option for patients with recurrent GCT of the cervical spine.

Serglycin induces osteoclastogenesis and promotes tumor growth in giant cell tumor of bone

Giant cell tumor of bone (GCTB) is an aggressive osteolytic bone tumor characterized by the within-tumor presence of osteoclast-like multinucleated giant cells (MGCs), which are induced by the neoplastic stromal cells and lead to extensive bone destruction. However, the underlying mechanism of the pathological process of osteoclastogenesis in GCTB is poorly understood. Here we show that the proteoglycan Serglycin (SRGN) secreted by neoplastic stromal cells plays a crucial role in the formation of MGCs and tumorigenesis in GCTB. Upregulated SRGN expression and secretion are observed in GCTB tumor cells and patients. Stromal-derived SRGN promotes osteoclast differentiation from monocytes. SRGN knockdown in stromal cells inhibits tumor growth and bone destruction in a patient-derived orthotopic xenograft model of mice. Mechanistically SRGN interacts with CD44 on the cell surface of monocytes and thus activates focal adhesion kinase (FAK), leading to osteoclast differentiation. Importantly, blocking CD44 with a neutralizing antibody reduces the number of MGCs and suppresses tumorigenesis in vivo. Overall, our data reveal a mechanism of MGC induction in GCTB and support CD44-targeting approaches for GCTB treatment.

Imaging following surgery for primary appendicular bone tumours

Primary bone tumours are uncommon, with sarcomas accounting for < 0.2% of all malignancies. The survival rate of primary bone sarcomas has significantly improved due to (neo)adjuvant therapy, while improved surgical techniques and development of new prostheses have shifted the surgical focus from amputation to limb preservation in the vast majority of patients. A wide variety of surgical options are available for the treatment of primary bone tumours which depend upon histological diagnosis, their appearance at the time of presentation and response to any (neo)adjuvant therapy as required. This review is intended to help radiologists familiarise themselves with the management of primary appendicular bone tumours and expected normal postoperative appearances for the various surgical techniques, and to recognise potential complications.

Management of the Cavity After Removal of Giant Cell Tumor of the Bone

Purpose: To find out the most appropriate management scheme through the analysis and comparison of different inactivation methods and filling materials. Method: A systematic literature search was performed using the terms, anhydrous ethanol, phenol, hypertonic saline, cryotherapy, thermal therapy, bone reconstruction, GCTB, and etc., Selected articles were studied and summarized. The mechanism, clinical effects, and influence on bone repair of various methods are presented. Recent developments and perspectives are also demonstrated. Recent Findings: Compared to curettage alone, management of the residual cavity can effectively reduce the recurrence of giant cell tumours of bone. It is a complex and multidisciplinary process that includes three steps: local control, cavity filling, and osteogenic induction. In terms of local control, High-speed burring can enlarge the area of curettage but may cause the spread and planting of tumour tissues. Among the inactivation methods, Anhydrous ethanol, and hyperthermia therapy are relatively safe and efficient. The combination of the two may achieve a better inactivation effect. When inactivating the cavity, we need to adjust the approach according to the invasion of the tumour. Filling materials and bone repair should also be considered in management.

Establishment and characterization of novel patient-derived cell lines from giant cell tumor of bone

Giant cell tumor of bone (GCTB) is a locally aggressive and rarely metastasizing tumor. GCTB is characterized by the presence of unique giant cells and a recurrent mutation in the histone tail of the histone variant H3.3, which is encoded by H3F3A on chromosome 1. GCTB accounts for ~ 5% of primary bone tumors. Although GCTB exhibits an indolent course, it has the potential to develop aggressive behaviors associated with local recurrence and distant metastasis. Currently, complete surgical resection is the only curative treatment, and novel therapeutic strategies are required. Patient-derived cancer cell lines are critical tools for basic and pre-clinical research. However, only a few GCTB cell lines have been reported, and none of them are available from public cell banks. Therefore, we aimed to establish novel GCTB cell lines in the present study. Using curetted tumor tissues of GCTB, we established two cell lines and named them NCC-GCTB2-C1 and NCC-GCTB3-C1. These cells harbored a typical mutation in histones and exhibited slow but constant growth, formed spheroids, and had invasive capabilities. We demonstrated the utility of these cell lines for high-throughput drug screening using 214 anticancer agents. We concluded that NCC-GCTB2-C1 and NCC-GCTB3-C1 cell lines were useful for the in vitro study of GCTB.

Tumor microenvironment in giant cell tumor of bone: evaluation of PD-L1 expression and SIRPα infiltration after denosumab treatment

Giant cell tumor of bone (GCTB) is an intermediate malignant bone tumor that is locally aggressive and rarely metastasizes. Denosumab, which is a receptor activator of nuclear factor kappa B ligand (RANKL) inhibitor, can be used to treat GCTB. We focused on potential immunotherapy for GCTB and investigated the tumor microenvironment of GCTB. Programmed death-ligand 1 (PD-L1) and indoleamine 2,3-dioxygenase 1 (IDO1) expression and signal-regulatory protein alpha (SIRPα), forkhead box P3 (FOXP3), and cluster of differentiation 8 (CD8) infiltration were assessed by immunohistochemical studies of 137 tumor tissues from 96 patients. Of the naive primary specimens, 28% exhibited PD-L1 expression and 39% exhibited IDO1 expression. There was significantly more SIRPα⁺, FOXP3⁺, and CD8⁺ cell infiltration in PD-L1- and IDO1-positive tumors than in PD-L1- and IDO1-negative tumors. The frequency of PD-L1 expression and SIRPα⁺ cell infiltration in recurrent lesions treated with denosumab was significantly higher than in primary lesions and recurrent lesions not treated with denosumab. PD-L1 expression and higher SIRPα⁺ cell infiltration were significantly correlated with shorter recurrence-free survival. PD-L1 and SIRPα immune checkpoint inhibitors may provide clinical benefit in GCTB patients with recurrent lesions after denosumab therapy.

New Target for Precision Medicine Treatment of Giant-Cell Tumor of Bone: Sunitinib Is Effective in the Treatment of Neoplastic Stromal Cells with Activated PDGFRβ Signaling

Simple Summary

The purpose of this study was to analyze differential cell signaling in response to denosumab treatment to identify and subsequently inhibit molecular targets in the neoplastic stromal cell population, which poses a risk for tumor recurrence. Using phosphoprotein arrays, a distinct signaling profile was detected in GCTB tissues treated with denosumab, a specific RANKL antibody, which coincided with the RTK profile in derived cell lines. PDGFRβ was selected as a promising receptor target, and its inhibition by the small-molecule inhibitor sunitinib resulted in potent inhibition of cell proliferation in vitro. The addition of sunitinib to denosumab resulted in the disappearance of both multinuclear giant cells and neoplastic stromal cells, as reported here. Thus, sunitinib could become an effective addition to denosumab in the treatment of GCTB with activated PDGFRβ.

Abstract

Giant-cell tumor of bone (GCTB) is an intermediate type of primary bone tumor characterized by locally aggressive growth with metastatic potential. The aim of this study was to identify new druggable targets among the cell signaling molecules involved in GCTB tumorigenesis. Profiles of activated signaling proteins in fresh-frozen tumor samples and tumor-derived cell lines were determined using phosphoprotein arrays. Analysis of the obtained data revealed epidermal growth factor receptor (EGFR) and platelet-derived growth factor receptor beta (PDGFRβ) as potential targets, but only the PDGFR inhibitor sunitinib caused a considerable decrease in stromal cell viability in vitro. Furthermore, in the case of a 17-year-old patient suffering from GCTB, we showed that the addition of sunitinib to the standard treatment of GCTB with the monoclonal antibody denosumab resulted in the complete depletion of multinucleated giant cells and mononuclear stromal cells in the tumor tissue. To summarize, the obtained data showed that a specific receptor tyrosine kinase (RTK) signaling pattern is activated in GCTB cells and plays an important role in the regulation of cell proliferation. Thus, activated RTKs and their downstream signaling pathways represent useful targets for precision treatment with low-molecular-weight inhibitors or with other types of modern biological therapy.

Selective and caspase-independent cytotoxicity of bioactive glasses towards giant cell tumor of bone derived neoplastic stromal cells but not to bone marrow derived stromal cells

Semi-malignant giant cell tumors of bone (GCTB) are associated with large osteolytic defects and significant bone destructions. Surgical resection remains the standard therapy that is, however, associated with very high recurrence rates. Bioactive glasses (BGs) that are osteogenic but under certain conditions also cytotoxic might be suitable to achieve biological reconstruction with simultaneous reduction of tumor recurrence in GCTB. In this study, a concentration and time dependent cytotoxic effect of five different BG compositions towards neoplastic GCTB cells was identified while bone marrow derived mesenchymal stromal cells were mostly unaffected. Time course and extent of the cytotoxic effect were dependent on the BG composition and were not associated with caspases activation, indicating that apoptotic mechanisms are not involved. Rather, detection of BG-induced disruption of the cell membranes and a rapid drop of intracellular HMG1 (High Mobility Group Box 1 protein) levels suggest a necrotic cell death. Notably, the cytotoxic effects were dependent on a direct contact of cells and BGs and could not be observed using indirect cultivation settings. Our data suggest that BGs might represent promising materials for the treatment of GCTB in order to reduce tumor recurrence with simultaneous enhancement of bone regeneration.

Giant cell tumor of bone - Analysis of 213 cases involving extra-craniofacial bones

We elucidated clinicopathological characteristics of giant cell tumor of bone (GCTB) in Japan, and significant clinicopathological factors for predicting local recurrence. Clinicopathological profiles of 213 patients with GCTB (100 male, 113 female) involving extra‐craniofacial bones were retrieved. Pathological slides obtained at the initial surgery were reviewed. Fourteen pathological and five clinical features were statistically analyzed to disclose prognostic significance. Patient age ranged from 12–80 years (Average 38.7). Long bones were most frequently affected (86.4%), especially around the knee (62.9%). Histological features are basically similar to those previously reported. Within a follow‐up period (24–316 months, average 106.1 months), the local recurrence rate is 29.1%. Metastasis has occurred in 9 patients. Cox regression analysis of representative clinicopathological features shows that younger age, higher mitotic count, smaller zones of stromal hemorrhage, considerable vascular invasion and absence of ischemic necrosis are significant predictors for local recurrence. Initial operative method (curettage) is a significant risk factor in univariate analysis but not by multivariate analysis (P = 0.053). Denosumab administration increases risk but not significantly (P = 0.053). Histone 3.3 G34W immunopositivity is not significant for predicting local recurrence.

Understanding giant cell sarcoma of the head and neck: A population-based study

BACKGROUND

Giant cell sarcomas (GCS) are rare head and neck neoplasms.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was analyzed for all patients who have been diagnosed with GCS from 1973 to 2014.

RESULTS

Four hundred and forty cases of GCS of the head and neck were identified. The average age at diagnosis was 74.4 years, 86.8% were white, 82.5% were male, 70.7% were insured, and 88.2% lived in an urban metropolitan region. Connective tissue was the most frequent primary site (42.5%). The 5Y-DSS rate was 91.1%, while the 5Y-OS was 54.6% for all cases. Patients treated with surgery alone had the highest 5Y-DSS rate of 94.5. T-classification odds ratio was a significant predictor of survival accounting for confounding variables on multivariate analysis.

CONCLUSIONS

GCS presents most frequently in connective tissue of the head and neck with overall high probability of survival. The treatment of choice is surgery alone.

Clinical outcome of a conservative approach to giant cell tumor of ankle and foot bones

Giant cell tumor of the bone (GCTB) affecting foot and ankle is rare, and the literature available on their clinical behavior and reconstructive options is scarce. Many authors consider these sites a special subset with high rates of local recurrence. Eighteen patients with GCTB of foot and ankle were treated from (March 2014 to February 2020). Extended curettage was offered wherever feasible. Twelve patients underwent extended curettage, three underwent resection and reconstruction, one patient had ray amputation, one had below knee amputation. One patient with multifocal disease was treated conservatively with denosumab. There were 11 females and the mean age was 31.7 years. Distal tibia (11 patients) was the commonest location, followed by the first metatarsal (four patients). At a median follow up of 46 months, two patients out of the 17 operated had a local recurrence. GCTB affecting the foot and ankle have a clinical course comparable to those at other locations. They should be treated with a conservative approach, where radical resection and amputation are reserved for only the non-curettable tumors.

Primary Aneurysmal Bone Cyst and Its Recent Treatment Options: A Comparative Review of 74 Cases

(1) Background: An aneurysmal bone cyst (ABC) is a benign, locally aggressive tumor. Different treatment modalities are described in the literature i.e., en bloc resection, intralesional curettage and percutaneous sclerotherapy. (2) Methods: This single-center study is a review of 74 patients with primary ABCs who underwent a surgical treatment or polidocanol instillation. Cyst volume measurements using MRI and conventional radiographs are compared. (3) Results: The mean pre-interventional MRI-based cyst volume was 44.07 cm³ and the mean radiographic volume was 27.27 cm³. The recurrence rate after intralesional curettage with the need for further treatment was 38.2% (13/34). The instillation of polidocanol showed a significant reduction of the initial cyst volume (p < 0.001) but a persistent disease occurred in 29/32 cases (90.6%). In 10 of these 29 cases (34.5%) further treatment was necessary. After en bloc resection (eight cases) a local recurrence occurred in two cases (25%), in one case with the need for further treatment. (4) Conclusions: MRI scans are superior to biplanar radiographs in the examination of ABCs. Sequential percutaneous instillations of polidocanol are equally effective in the therapy of primary ABCs compared to intralesional curettage. However, several instillations have to be expected. In a considerable number of cases, a conversion to intralesional curettage or en bloc resection may be necessary.

A giant cell tumor of the bone in the rib cage left to proliferate unfettered for seven years to an extensive size

Giant cell tumors of the bone are generally benign tumors of the bone, though they can be locally invasive in nature. They are also known as "osteoclastomas," and patients are typically between 20 and 40 years of age, who present with pain and swelling of the joints. Though the tumor is benign, malignant degeneration, metastasis, and other complications of tumor growth are possible. Here we present a case where a delay in treatment led to a significant tumor burden. This tumor's unique location in the anterior arc of the rib, as well as its growth to a size that has rarely been reported, ultimately caused major compressive effects that significantly impacted our patient's quality of life.

Origin and Use of Hydrogen Peroxide in Neurosurgery

Hydrogen peroxide (H2O2) is a chemical with a wide range of applications. This includes its use in the medical field, in which its use has been ubiquitous but is most useful as an antiseptic and in achieving hemostasis. Neurosurgeons have been using H2O2 for well over a century, primarily for its hemostatic and antiseptic effects. This is in spite of the fact that the actual effectiveness of H2O2 as an antiseptic is questionable, and its use, in general, may be more dangerous than it appears. We review the application of H2O2 in medicine generally and, more specifically, in neurosurgery. This review outlines the reasoning behind the use of H2O2 as an antiseptic and details why it may not be as effective as one might think. We also detail its use as a hemostatic agent in neurosurgery, reviewing a number of techniques in which it has been useful in this role. Finally, we review the documented cases of complications associated with the use of H2O2 in neurosurgery. Ultimately, we conclude that the use of H2O2 in neurosurgery be reconsidered because of its lack of effectiveness as an antiseptic and potentially fatal complications.

Multiprofessional Management of Giant Cell Tumors in the Cervical Spine: A Systematic Review

BACKGROUND

Giant cell tumors of the bone (GCTB) are rare bone tumors, especially in the cervical spine. Generally considered benign, local aggressiveness and metastatic growth have been described. Surgical concepts for GCTB are challenged by complex neurovascular anatomy. Specific clinical management guidelines are nonexistent. This systematic review aims to compile existing evidence on the treatment of GCTB of the cervical spine.

METHODS

Four electronic databases were searched: Medline, Embase, Web of Science, and Cochrane Library. All clinical studies reporting the treatment of GCTB in the human cervical spine in English language were found eligible for review.

RESULTS

Seven studies were included in the synthesis including a total number of 54 patients. Of those patients, 46 (85%) were treated for naive nonrecurrent GCTB. Only 1 study is considered a cohort study; all other studies were case reports. Generally, intralesional procedures were performed in 13 (24%) cases. Subtotal resections were reported for 11 (20%) patients. Twenty-eight (52%) patients were surgically treated with piecemeal resection, en-bloc resection, or spondylectomy. Thirty-six (67%) patients underwent adjuvant radiotherapy. A combination of radiotherapy and chemotherapy was reported in 2 (4%) cases. Bisphosphonates were prescribed for 9 (17%) patients. Inconsistent reporting of outcome data did not allow for comparative analyses.

CONCLUSIONS

Best available evidence suggests that the most aggressive surgical approach should be the main goal of any GCTB surgery. No specific adjuvant or neoadjuvant treatment can be recommended as superior due to a lack of comparative data. Therapeutic approaches need to be planned thoroughly on an individual basis.

Denosumab Treatment for Giant Cell Tumors, Aneurysmal Bone Cysts, and Fibrous Dysplasia-Risks and Benefits

PURPOSE OF REVIEW

This review summarizes current understanding of the role of denosumab, an inhibitor of receptor activator of nuclear kappa-B ligand (RANKL), in the management of 3 skeletal neoplasms: giant cell tumors, aneurysmal bone cysts, and fibrous dysplasia.

RECENT FINDINGS

A growing body of literature supports denosumab use in giant cell tumors, a neoplasm in which RANKL plays a clear pathogenic role. Comparatively less data is available in aneurysmal bone cysts and fibrous dysplasia; however, the pathogenic similarity of these disorders to giant cell tumors, as well as encouraging preliminary data, suggests denosumab may be useful. Denosumab's inhibitory effects on bone turnover are fully reversible after drug discontinuation. This raises important unanswered questions for clinical management, including potential risks of tumor recurrence and bone turnover rebound. Denosumab is a promising potential treatment for skeletal neoplasms. However, its clinical use is impacted by ongoing safety concerns related to postdiscontinuation rebound, particularly in children. There is a critical need to understand denosumab treatment and discontinuation effects on tumor recurrence and to develop strategies for long-term treatment in patients who cannot be managed surgically.

Giant Cell Tumor of Bone: An Update

PURPOSE OF REVIEW

To highlight the new developments in the management of advanced giant cell tumor of bone, a rare locally aggressive benign tumor, which was traditionally managed with surgery alone by either curettage and local adjuvant therapy, wide resection, or marginal excision. Here, we review the current role of systemic therapy for management of locally advanced or metastatic giant cell tumor of bone (GCTB).

RECENT FINDINGS

The elucidation of the pathophysiology of giant cell tumor of bone, especially with regards to the role of nuclear factor kappa B ligand (RANKL), has led to the Food and Drug Administration (FDA) approval of denosumab in the management of locally advanced or metastatic GCTB. For advanced giant cell tumor where surgical resection alone can cause severe morbidity, the paradigm has shifted from local treatment alone to multidisciplinary management with the consideration of use of denosumab.

A case of pelvic giant cell tumor of bone, complete remission with denosumab: long duration of response

Although giant cell tumor of bone has been considered as a disease with benign course, it can lead to bone destruction and serious morbidity. A 19-year-old case was presented with hip pain. There was a recurrence after 9 months of curative surgical resection and zoledronic acid use, and as surgical morbidity would be high, antiosteoclastic receptor activator of nuclear factor kappa B ligand inhibitor denosumab treatment was administered. She had a complete remission after 18 months of denosumab treatment. The important point in the present case is that it has been followed up without recurrence after around 42 months of denosumab use and 11 months of follow-up after the cessation of drug. In recurrent cases in which nonmetastatic surgery is not suitable, the use of denosumab decreases tumor progression. The duration of use in unresectable and advanced cases still remains unclear.

Unusual presentation in Haiti of a recurrent giant cell tumor of bone affecting the distal radius: A case report

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En bloc resection with centralization is a viable approach in low-resource areas.

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Multidisciplinary surgical approaches are necessary in low-resource settings.

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Loss of motion can be compensated with proper rehabilitation measures.

Introduction

Giant cell tumor of bone (GCTB) is a benign-aggressive tumor that has a high-rate of recurrence with curettage resection alone. Patients with GCTB in underserved regions of the world can have progression of the tumor with significant disability due to a lack of specialty care. We present a case of an en bloc resection of an aggressive, recurrent GCTB of the radius with excellent function and no evidence of tumor recurrence two years after surgery.

Presentation of case

A 22-year-old right-hand dominant female in Haiti developed an aggressive recurrence of a giant cell tumor of bone (GCTB) of the distal radius. Treatment consisted of en bloc resection of the distal radius with the proximal row of the carpus and centralization of the ulna. At two-year follow-up, the patient maintained good functional capacity with no clinical or radiological evidence of recurrence.

Discussion

GCTB can cause significant destruction of the bone and articular surface if not treated adequately. Treatment options should be considered carefully in underserved regions of the world based on the resources available. This case exemplifies that complex limb-salvage surgery is possible when coordination of care between international and local surgeons is provided with an emphasis on continuity of care post-operatively.

Conclusion

En bloc resection with centralization of the ulna remains a viable technique to address aggressive GCTB of the distal radius and can be appropriate in resource-limited settings.

Preoperative denosumab treatment with curettage may be a risk factor for recurrence of giant cell tumor of bone

PURPOSE

Giant cell tumor of bone (GCTB) is a local aggressive bone tumor, histologically classified as intermediate malignancy. Recently, the RANKL inhibitor, denosumab, was developed as a novel and effective treatment option for GCTB. Since the risk of preoperative use of denosumab with curettage had been previously reported, this study aimed to investigate the relationship between recurrences and clinicopathological features associated with adjuvant denosumab treatment in GCTB.

METHODS

A total of 87 GCTB cases were treated at our institution. We reviewed 66 patients with conventional-type GCTB occurring in the extremities and analyzed 78 surgical treatments, including curettages and resections, with clinicopathological features and denosumab treatment.

RESULTS

GCTB lesions, including 66 primary and 12 recurring, underwent surgical treatment like curettage and resection. Recurrence-free survivals in 78 GCTB surgeries were 78.7% in 3 years and 71.9% in 5 years. In the resected cases of GCTBs, there was no recurrence either with or without denosumab. In curettage cases, 3-year recurrence-free survivals were 0.0% (n = 3) in preoperative treatment of denosumab, 66.7% (n = 6) in postoperative treatment, and 76.6% (n = 43) in no treatment. Interestingly, three preoperative treatment cases demonstrated low MIB-1 index despite 100% recurrence. The other clinicopathological factors did not contribute much to the risk of recurrence in curettage cases.

CONCLUSION

Our findings revealed the use of denosumab in GCTB, prior to curettage, to possibly increase the risk of local recurrence. Together with previous reports, our finding might provide information for beneficial treatment of GCTB.

A comparison of depth of necrosis among adjuvant therapies used for the treatment of benign bone tumors

BACKGROUND AND OBJECTIVES

Benign bone tumors are often treated with extended curettage utilizing an adjuvant therapy to eliminate any remaining tumor cells. The purpose of this study was to explore and compare the histologic depth of necrosis created by various adjuvant therapies used in the treatment of benign bone tumors.

METHODS

A high-speed burr was utilized to create cortical defects within porcine humeri and femora. Phenol, polymethyl methacrylate (PMMA), argon beam coagulation (ABC), liquid nitrogen, and the Bipolar Hemostatic Sealer (BHS) were each applied to five defects, with an additional five defects left untreated as a control. The maximal depth of necrosis was determined under microscopic examination.

RESULTS

The phenol, PMMA, ABC, liquid nitrogen, and BHS demonstrated an average histologic depth of necrosis of 0.30, 0.78, 2.54, 2.54, and 0.92 mm, respectively, each of which was significantly increased compared to the control group (p = .001, .003, .003, .01, and  <.001). Their respective variances, a measure of reproducibility, were 0.01, 0.09, 0.96, 1.93, and 0.03 mm² .

CONCLUSION

This study confirms, through histologic analysis, adjuvant therapies create a rim of cellular necrosis beyond that of burring during extended curettage, supporting their use in the treatment of benign bone tumors. Furthermore, it provides a head-to-head comparison.

Novel Strategy of Curettage and Adjuvant Microwave Therapy for the Treatment of Giant Cell Tumor of Bone in Extremities: A Preliminary Study

Objectives

To evaluate whether curettage with adjuvant microwave therapy was successful in the treatment of giant cell tumor of the bone (GCTB) in extremities, especially for GCTB with pathological fractures and GCTB of the distal radius.

Methods

This was a retrospective study of 54 cases of GCTB of the extremities treated by curettage with adjuvant microwave therapy between 2007 and 2019. Five patients were lost to follow up and excluded from the study. A total of 33 male and 21 female patients were included in this study. Patients were aged 15–57 years (mean 29.72 ± 10.48 years). Among these patients, there were 10 cases of GCTB with pathological fractures and eight cases of GCTB of the distal radius; one of these cases was combined with a pathological fracture. Comprehensive imaging examinations (X‐rays [including lesion site and chest], CT, MRI, emission computed tomography, and pathology examination) of all patients were reviewed. The clinical staging of these patients were evaluated radiologically using the Campanacci classification system based on the extent of spread of the tumor. All patients underwent curettage with adjuvant microwave therapy. Clinical and imaging evaluations were performed in all cases to check for recurrence or metastasis. Lower limb and upper limber function were assessed using the Musculoskeletal Tumor Society score (MSTS), and wrist function was assessed according to the disabilities of the arm, shoulder and hand (DASH) score. Data on surgical‐related complications were recorded.

Results

All cases were followed up for 24–126 months (mean 60.69 ± 29.61 months). There were 24 patients with a Campanacci grade of 3 and 30 with a Campanacci grade of 2. The 52 patients were continuously disease‐free. The local recurrence rate was 3.70% (2 patients). One patient had recurrence in the proximal femur, and the other developed in soft tissue of the calf muscle. No recurrence occurred for GCTB of the distal radius. One recurrence occurred in a GCTB with pathological fractures. The intervals were 9 and 28 months, respectively. The cases of recurrence all had a Campanacci grade of 3 (8.33%). The median MSTS among the 54 patients was 27.67 ± 3.81. The mean wrist function DASH score was 8.30 ± 2.53. The mean MSTS was 28.67 ± 1.63 and 26.71 ± 5.49 for patients with GCTB of the distal radius and for those with pathological fractures, respectively. In comparing patients with and without pathological fractures, there was no significant difference in the MSTS functional score. Five patients had complications after the surgery.

Conclusion

Curettage with adjuvant microwave ablation therapy provided favorable local control and satisfactory functional outcomes in the treatment of GCTB, especially for cases with pathological fractures and those with GCTB of the distal radius.

Current concepts in the treatment of giant cell tumour of bone

PURPOSE OF REVIEW

Giant cell tumour of bone (GCTB) is an intermediate, locally aggressive primary bone tumour. In addition to local therapy, new drugs became available for this disease. Denosumab, a receptor activator of nuclear factor κ-B-ligand inhibitor, was introduced as systemic targeted therapy for advanced or inoperable and metastatic GCTB. Also, the bisphosphonate zoledronic acid has activity in GCTB by directly targeting the neoplastic stromal cells.

RECENT FINDINGS

In a small RCT, bisphosphonates were successful in controlling tumour growth and a higher apoptotic index of tumour cells was seen after zoledronic acid versus controls. Although bisphosphonate-loaded bone cement has not been studied to a large extent, it does not seem harmful and may constitute a logical local adjuvant. From the largest clinical trial to date, the risk-to-benefit ratio for denosumab in patients with advanced GCTB remains favourable, also in facilitating less morbid surgery. Concerns have arisen that recurrence rates would be higher than after conventional treatment, ranging from 20 to 100% in a systematic review, although this may be because of bias. H3F3A (G34W) driver mutations are helpful in the differentiation between GCTB and other giant cell-containing malignancies. H3.3-G34W proved sufficient to drive tumourigenesis. The cumulative incidence of malignancy in GCTB is estimated at 4%, of which primary malignancy 1.6% and secondary malignancy 2.4%, the latter mainly after radiation. To date, a potential causal relationship between denosumab and pulmonary metastases has not been confirmed; if they do not behave indolently, it would be advised to reassess diagnosis and consider malignancy.

SUMMARY

Denosumab remains a highly effective treatment option for patients with advanced GCTB. A short duration of 2-4 months neoadjuvant denosumab is advised to facilitate less morbid surgery and prevent incomplete curettage by macroscopic tumour alterations. Reduced dose intensity is being studied to reduce long term side-effects. Further research on bisphosphonates and other targets including H3.3-G34W remains warranted.

Giant Cell Tumor: Changing Behavior from Intraorbital to Intraosseous Mass

Purpose

To present a patient with giant cell tumor (GCT) of the orbit by changing behavior from an intraorbital mass to an intraosseous tumor.

Methods

A 16-year-old boy presented with pain, swelling, erythematous of the left upper and lower eyelids, proptosis, and diplopia. Ophthalmic examination revealed chemosis, conjunctival injection, limited elevation, depression as well as abduction in the left eye.

Results

Multislice computed tomography scan (CT scan) of the orbit and paranasal sinuses showed a hyperdense, oval, extraconal mass with bone erosion. Magnetic resonance imaging of the orbit showed an inferior lateral isointense, oval, extraconal mass that had indented the globe. The patient underwent superior lateral orbitotomy, and the orbital mass was excised. Two months later, the patient developed proptosis, severe chemosis, and eyelid erythema in the same eye. CT scan showed an intraosseous mass in the lateral wall of the orbit that had pushed the globe anteromedially. Intraosseous tumor was resected, and the lateral orbital wall was drilled during the second surgery. GCT was diagnosed based on pathological survey.

Conclusion

Following the resection of the orbital GCT, the tumor behavior may change to an intraosseous lesion.

Recurrence Rate of Giant Cell Tumor With the Treatment of Scooping Curettage, Burr Down Technique, Phenolization, and Bone Cement

Objective: To find the recurrence and outcomes of giant cell tumors treated with scooping curettage, burr down technique, phenolization, and bone cement.

Method: We conducted a descriptive case series using a non-probability consecutive sampling technique at the Department of Orthopedics, Lahore General Hospital, Lahore, Pakistan, from May 2014 to June 2018. A total of 40 patients aged between 20 to 40 years with Compannacci grade I, II & III giant cell tumors (GCT) were included and patients unfit for the surgery, those with multiple, recurrent, malignant giant cell tumors, tumors involving the axial skeleton, and previously treated cases were excluded. We recorded the side, site of the tumor, post-operative distal neurovascular status, and recurrence of giant cell tumors. The patients were follow-up in the out-patient department (OPD) at the second week, fourth week, 12th week, 24th week, 48th week, 96th week, and 144th week after the surgery. Side, site of the tumor, and post-operative distal neurovascular status were assessed clinically, and recurrence of the tumors was observed clinically and radiologically.

Results: The mean age of all patients was 25.75±5.74 years. Males were 45% (18) and females were 55% (22). Most (12, 30%) tumors were present in the upper limb, and 22 (70%) were present in the lower limb. The majority (24, 60%) tumors were present around the knee joint. Companacci grade I was five (12.5%), grade II was 14 (35%), and grade III was 21 (52%). There were six (15%) pathological fractures. There was no case of distal neurovascular (DNV) injury, and three patients had a recurrence in two years of follow-up.

Conclusion: Giant cell tumor treated with scooping curettage, burr down technique, phenolization and poly-methyl methacrylate showed 7.5% recurrence. The combined use of local adjuvants in the treatment of giant cell tumors is a safe and effective way to reduce the rate of local recurrence.

Sacral Giant Cell Tumor-Induced Cauda Equina Syndrome: Case Report with Successful Management

Sacral giant cell tumor (GCT) is a rare entity. It often presents late after massive enlargement of tumor. Here we are reporting a case of sacral GCT treated successfully at our institute. A 30-year-old male patient presented with paraplegia, significant sensory disturbance below L2 level, along with severe vesicorectal dysfunction. On imaging, giant mass was seen filling the sacrum with homogenous enhancement and flow voids from L5 level to S4 level. The patient underwent surgical exploration with L4–5 decompressive laminectomy, near-total resection of tumor, and lumboiliac fixation. The patient recovered symptomatically in postoperative period. Sacral GCT is a rare but treatable lesion. Its presentation as sudden cauda equina syndrome is rare, but final management should be aggressive with en bloc resection and fixation.

Does Osteoarticular Allograft Reconstruction Achieve Long-term Survivorship after En Bloc Resection of Grade 3 Giant Cell Tumor of Bone?

BACKGROUND

En bloc resection of benign tumors is only indicated in aggressive lesions with substantial destruction of the affected bone. Few reports have evaluated the long-term outcome of Grade 3 giant cell tumor of bone (GCTB; defined as severe bone destruction and soft tissue extension) treated with en bloc resection and reconstruction with a massive allograft. We recently reported that patients with benign tumors achieved better allograft reconstruction survivorship compared with those treated for a malignant bone tumor. In light of that finding, we wondered whether osteoarticular allografts would be a viable long-term alternative for Grade 3 GCTB, which could be important in some countries because of greater availability and lower costs compared with endoprostheses.

QUESTIONS/PURPOSES

We analyzed a group of patients with Grade 3 GCTBs treated with en bloc resection and osteoarticular allograft reconstruction in terms of (1) survivorship free from allograft removal at 10 years; (2) survivorship free from reoperation for any reason at 10 years, (3) functional results as measured by the Musculoskeletal Tumor Society (MSTS) score, (4) assessment of arthrosis at the knee.

METHODS

We retrospectively analyzed all patients with a Grade 3 GCTB treated between 1980 and 2007. Only patients treated with en bloc resection and reconstruction with massive osteoarticular allografts were included in the analysis. The indication for osteoarticular reconstruction during that time included severe bone destruction with intraarticular compromise of the tumor, intraarticular fracture because of tumor growth, the presence of inadequate remaining subchondral bone to resist normal loading (for the distal femur or proximal tibia), and the preservation of a soft-tissue component (ligaments or meniscus) for articular stability. During the period, 75 patients were treated with en bloc resection. Patients treated with intralesional curettage (n = 7), reconstruction with an endoprosthesis (n = 2), intercalary arthrodesis (n = 13), or unicondylar reconstruction (n = 14) were excluded. Of the original 75 treated with en bloc resection, 52% (39) were treated with osteoarticular allograft reconstruction, and no patient was lost to follow-up before 2 years or had substantial missing data. However, of the 39 patients, another 21% (8) have not been seen in the last 5 years, but these were included here because they reached the 10-year minimum surveillance period before being lost. Twenty-three of those 39 patients were previously reported by our group and 16 new patients (treated between 1980-1985) were included in this series (eight distal radius, six distal femur, two proximal tibias), extending the follow-up period and including more patients for analysis. The median (range) follow-up duration was 26 years (10 to 34). We assessed survivorship using a Kaplan-Meier analysis, we drew MSTS scores retrospectively from patients´ medical records, and we graded arthrosis using the Ahlbäck scale for the knee (which was by far the most common joint involved, n = 31, and so it was the joint we assessed for the presence of arthrosis).

RESULTS

The survivorship free from allograft removal was 85% at 10 years (95% CI 74 to 96). The allograft survivorship free from reoperation for any reason at 10 years was 72% (95% CI 59 to 87). The median (range) MSTS score was 28 points (19 to 30). The grade of arthrosis in the knee at last follow-up was analyzed in 20 patients and classified in nine as Ahlbäck Type 4, in six as Type 3, in three as Type 2 and in two as Type 5.

CONCLUSIONS

Osteoarticular allograft reconstruction after a Grade 3 GCTB en bloc resection showed excellent long-term survivorship. We believe these results compare favorably with other studies on endoprosthetic reconstruction and head-to-head studies of these approaches should be performed; these would need to be multicenter trials. In the meantime, in locations where endoprostheses are unavailable or too expensive, we believe our results support the use of osteoarticular allografts.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Integration of denosumab therapy in the management of giant cell tumors of bone

A review of the literature indicated denosumab is gaining favorability in the oncology community, particularly with increasing frequency in GCTB. Will denosumab be the breakthrough GCTB treatment? Here, we provide a pertinent case example, a review of the literature regarding the history and basic science behind the use of denosumab for GCTB, highlight the newest insights into the dosing and duration of treatment, and note advancements in the field.

The impact of curettage technique on local control in giant cell tumour of bone

INTRODUCTION

Although consensus has been reached regarding the main aspects of intralesional surgery for giant cell tumour of the bone (GCTB), debates continue about the most effective combination of local adjuvants. The purpose of study was to analyze the previous experience and determine the most effective curettage approach for GCTB.

METHODS

We summarized the findings from 89 papers published from 1962 to 2020 related to this subject. Database consisted of 137 treated groups that included 6441 patients who underwent different curettage techniques without pre-operative administration of bisphosphonates or RANKL inhibitors.

RESULTS

Recurrence rates after simple curettage ranged between 27 and 82% with a median value at 47%. The use of one or two local adjuvants reduced the incidence of recurrences approximately by 50% when compared with simple curettage. High-speed burring combined with chemical adjuvants or followed by poly(methyl methacrylate) cementation with or without bone grafting further improved the local control leading to good and excellent results; however, these were not documented in all studies. Simultaneous use of burring, chemical adjuvants, and cementation, which we named here as combined curettage, allowed to down local relapses to the range of 0-26%, with a median at 11%. Oncologic outcomes after combined curettage are significantly better when compared with simple curettage (p < 0.0001) and other variants of enhancement (p = 0.001).

CONCLUSIONS

Combined curettage appears to provide the most potent and comprehensive impact on residual tumour cells located in risk zones. This approach should be considered for locally advanced tumours when function-preserving surgery is planned. Additional comparative studies are required to define the optimal curettage enhancement for each individual patient.

Denosumab in Giant Cell Tumor of Bone: Current Status and Pitfalls

Denosumab is a monoclonal antibody against RANK ligand for treatment of giant cell tumor of bone (GCTB). Clinical trials and case series have demonstrated that denosumab is relevant to beneficial tumor response and surgical down-staging in patients of GCTB. However, these trials or case series have limitations with a short follow-up. Recent increasing studies revealed that denosumab probably increased the local recurrence risk in patients treated with curettage. This may be caused by the thicken bone margin of tumor that trapped tumor cells from curettage. The direct bone formation by tumor cells in the margin after denosumab treatment also contributed to the local recurrence. in vitro studies showed denosumab resulted in a cytostatic instead of a true cytotoxic response on neoplastic stromal cells. More importantly, denosumab-treated GCTB exhibited morphologic overlap with malignancy, and a growing number of patients of malignant transformation of GCTB during denosumab treatment have been reported. The optimal duration, long term safety, maintenance dose, and optimum indications remain to be elucidated. With these concerns in mind, this review warns that the denosumab therapy of GCTB should be applied with caution.

Extended curettage versus en bloc resection for the treatment of grade 3 giant cell tumour of the knee with pathologic fracture: a retrospective study

PURPOSE

For the treatment of giant cell tumour of the bone (GCTB) around the knee, preserving the native joint confers advantages over scarifying it. But, there is a controversy about the efficacy of intralesional curettage versus en bloc resection for treatment of such lesions. In this study, we compared local recurrence, functional outcomes, and complications of extended curettage and en bloc resection in these lesions.

METHODS

Patients with grade 3 GCTB of the distal femur or proximal tibia who were presented with a pathologic fracture and treated with either en bloc resection (n = 22) or extended curettage (n = 20) were included. The mean follow-up of the patients was 6.4 ± 1.9 years in the resection group and 5.5 ± 2.4 years in the extended curettage group. The primary outcome was a local recurrence. Secondary outcomes were limb function evaluated by the Musculoskeletal Tumor Society (MSTS) score and rate of complications.

RESULTS

Local recurrence was seen in four (20%) patients of the curettage group and three (13.7%) patients of the resection group (P = 0.69). The mean MSTS score was 24 ± 1.9 in the resection group and 26.5 ± 1.3 in the curettage group (P < 0.001). The number of complications was not significantly different between the two study groups (P = 0.49). However, the number of complications that required revision surgery was significantly more in the resection group (P = 0.049).

CONCLUSION

In grade 3 GCTB around the knee with pathologic fracture, extended curettage results in comparable oncologic outcomes to en bloc resection, while providing better function and a lower rate of revision.

Secondary Osteoarthritis After Curettage and Calcium Phosphate Cementing for Giant-Cell Tumor of Bone Around the Knee Joint: Long-Term Follow-up

Giant-cell tumor of bone (GCTB) is a locally aggressive intermediate bone tumor with a rarely metastasizing disposition. Standard surgical treatment consists of curettage, adjuvant treatment, and augmentation with allograft, autograft, or synthetics. Polymethylmethacrylate (PMMA) has been widely used for augmentation of the bone defect; however, the hyperthermic polymerization of PMMA may cause damage to articular cartilage, and the stiffness of the material may decrease the ability of the joint to absorb shock. These properties were reported to result in secondary osteoarthritis. Calcium phosphate cement has a low degree of thermal reaction and a strength that is similar to cortical bone. The aim of the present study was to investigate the incidence of secondary osteoarthritis around the knee joint following augmentation with calcium phosphate cement.

Mid-term results of intralesional extended curettage, cauterization, and polymethylmethacrylate cementation in the treatment of giant cell tumor of bone: A retrospective case series

OBJECTIVE

The aim of this study was to present the mid-term functional outcomes and recurrence rate in patients with giant cell tumor of bone (GCTB) treated by intralesional extended curettage, electrocauterization, and polymethylmethacrylate (PMMA) cementation.

METHODS

In this retrospective observational study, 79 consecutive patients (41 females, 38 males; mean age=39 years; age range=19-62 years) who were diagnosed and treated for GCTB between 2005 and 2017 were identified from hospital medical records. All patients were treated by intralesional extended curettage using high-speed burr, electrocauterization of the cavity, and filling the defect with PMMA. No additional local adjuvants were used. The mean follow-up period was 47 months (range=24-96). The tumors were graded according to the radiological classification system described by Campanacci. Functional outcomes were evaluated using the Musculoskeletal Tumor Society Score (MSTS) preoperatively, one year postoperatively, and at the final follow-up. Postoperative complications and recurrence rates were recorded.

RESULTS

Twenty-nine tumors were located in the distal femur, 23 in the proximal tibia, nine in the distal radius, five in the proximal humerus, five in the pelvis, three in the proximal fibula, two in the distal ulna, two in the distal tibia, and one in the second metatarsal. According to Campanacci classification, 37 tumors were grade III, 32 grade II, and 10 grade I. The mean MSTS score was 46.1% (range 40.2 to 71.4%) preoperatively, 91.7% (range 73.3% to 100%) one year postoperatively, and 86.3 % (range 66.2% to 96,1%) at the final follow-up. The overall complication rate was 7.6%; which included local tumor recurrence in four patients, superficial wound infection in one, and deep wound infection in another. The recurrence rate was 5.1% (4 patients). Recurrent tumors were located at the distal femur in three patients and proximal tibia in one.

CONCLUSION

With satisfactory functional results and low recurrence rates at the mid-term follow-up, GCTB can be treated effectively with intralesional extended curettage, electrocauterization, and PMMA cementation.

LEVEL OF EVIDENCE

Level IV, Therapeutic study.

Giant Cell Tumors of the Upper Extremity: Predictors of Recurrence

PURPOSE

Giant cell tumors (GCT) of the distal radius are thought to be more aggressive than in other locations. Therefore, the aim of this study was to investigate factors associated with recurrence of GCTs in the upper extremity.

METHODS

We retrospectively identified 82 patients who underwent primary surgical treatment for an upper extremity GCT. Tumors were located in the radius (n = 47), humerus (n = 17), ulna (n = 9), and hand (n = 9). Treatment consisted of either wide resection or amputation or intralesional resection with or without adjuvants. A multivariable logistic regression was performed including tumor grade, type of surgery, and tumor location, from which the percentage of contribution to the model of each variable was calculated.

RESULTS

The recurrence rate after intralesional resection was 48%; after wide resection or amputation, it was 12%. Two patients developed a pulmonary metastasis (2.4%). In multivariable analysis, intralesional resection was independently associated with recurrence. Intralesional resection had a 77% contribution to predict recurrence and the distal radius location had a 16% contribution in the predictive model.

CONCLUSIONS

As expected, intralesional resection was the strongest independent predictor of recurrence after surgical treatment for GCT. The distal radius location contributed to the prediction of giant cell tumor recurrence to a lesser extent.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

USP6-Associated Neoplasms: A Rapidly Expanding Family of Lesions

Nearly 20 years ago, the first description of a translocation involving chromosome 17 on which USP6 resides was described. Since then, not only the culprit gene but also many fusion partners, leading to transcriptional activation of USP6, have been detected. The first neoplasm known to harbor USP6 rearrangements was aneurysmal bone cyst. Since then, other entities like nodular fasciitis, myositis ossificans, fibro-osseous pseudotumor of digits, and a subgroup of fibromas of tendon sheath, probably representing tenosynovial nodular fasciitis, have been added to the list of USP6-rearranged lesions. Remarkably, all of them share clinical as well as morphological characteristics, and authors have suggested that these entities actually belong to the same spectrum. This review summarizes the current knowledge regarding USP6-rearranged lesions and further elaborates on how these neoplasms relate to one another. We propose to call these lesions UAN (Usp6-associated neoplasm).

Role of (Neo)adjuvant Denosumab for Giant Cell Tumor of Bone

OPINION STATEMENT

Denosumab is a RANK ligand inhibitor approved for the treatment of giant cell tumor of bone. While the role of denosumab in the setting of advanced and unresectable disease is well established, its role in surgically resectable disease is currently under discussion. Several prospective and retrospective series on neoadjuvant therapy in potentially resectable tumor with high morbidity surgery reported a relapse rate of 10-20% after resection and 30-40% after curettage. At the same time, less morbid surgery has obvious clinical advantages for the patient, and several studies have shown the efficacy of denosumab in downgrading of the surgical procedure. Currently, the role of neoadjuvant denosumab in operable GCTB is limited to selected cases in which a diffuse reactive bone formation and peripheral ossification can make an easier surgical procedure, for example, in tumors with a large soft tissue component. A planned resection may become less morbid when preoperative denosumab is administered. Whenever a segmental resection is thought to be indicated at diagnosis, denosumab may be considered in the neoadjuvant setting. A preoperative course of 6 months is considered safe and effective. Two case scenarios are presented and critically discussed. Because of the high recurrence rates after denosumab treatment followed by curettage, we discourage the use of denosumab when curettage is considered feasible. In this setting, a short course of preoperative denosumab (2-6 months) may be considered for highly selected cases, for example in pathological fractures. The role of adjuvant denosumab needs further investigation. Long-term disease control has been reported in case of non-surgical lesions, even after treatment interruption, but there is no consensus on ideal treatment duration and dosage for these scenarios. In all cases, multidisciplinary discussion with oncology, pathologist, radiologist, and surgeons is mandatory. Patient's comorbidities, dental conditions, and preferences, including family planning, should always be taken into account.

The two faces of giant cell tumor of bone

Giant cell tumor (GCT) is a bone-destructive benign neoplasm characterized by distinctive multinucleated osteoclast-like giant cells with osteolytic properties distributed among neoplastic stromal cells. GCT is locally aggressive with progressive invasion of adjacent tissues and occasionally displays malignant characteristics including lung metastasis. GCT is characterized genetically by highly recurrent somatic mutations at the G34 position of the H3F3A gene, encoding the histone variant H3.3, in stromal cells. This leads to deregulated gene expression and increased proliferation of mutation-bearing cells. However, when GCT complicates Paget disease of bone (GCT/PDB) it behaves differently, showing a more malignant phenotype with 5-year survival less than 50%. GCT/PDB is caused by a germline mutation in the ZNF687 gene, which encodes a transcription factor involved in the repression of genes surrounding DNA double-strand breaks to promote repair by homologous recombination. Identification of these driver mutations led to novel diagnostic tools for distinguishing between these two tumors and other osteoclast-rich neoplasms. Herein, we review the clinical, histological, and molecular features of GCT in different contexts focusing also on pharmacological treatments.

Is Treatment with Denosumab Associated with Local Recurrence in Patients with Giant Cell Tumor of Bone Treated with Curettage? A Systematic Review

BACKGROUND

Denosumab, a monoclonal antibody that binds to receptor activation of nuclear factor-kappa ß ligand (RANKL), has been used as a drug to treat aggressive giant cell tumors of bone. It is unclear whether preoperative denosumab therapy is associated with the local recurrence risk in patients with giant cell tumors of bone treated with curettage. Early evidence suggests that denosumab treatment is associated with a reduction in local recurrence, but other studies have questioned that premise. Curettage after a short course of denosumab (3 to 4 months) has been recommended, especially for large, aggressive giant cell tumors in which complete curettage is difficult to achieve. No randomized studies have documented the benefit of this approach, and some investigators have reported higher local recurrence after denosumab treatment. Due to this confusion, we performed a systematic analysis of existing reports to attempt to answer this question and determine whether the appropriate preoperative denosumab therapy duration could be established.

QUESTIONS/PURPOSES

(1) Is the use of preoperative denosumab associated with local recurrence risk in patients with giant cell tumors of bone treated with curettage compared with those treated with curettage alone? (2) Is the preoperative denosumab therapy duration associated with local recurrence after curettage?

METHODS

We searched the PubMed, EMBASE, and CENTRAL databases on April 26, 2019 and included both randomized and non-randomized studies that compared local recurrence between patients who had giant cell tumors of bone and were treated with curettage after preoperative denosumab and patients treated with curettage alone. Two authors independently screened the studies. There were no randomized studies dealing with denosumab in giant cell tumors of bone, and generally, denosumab was used for more aggressive tumors. We assessed the quality of the included studies using the Risk of Bias Assessment tool for Non-randomized Studies, with a moderate overall risk of bias. We registered our protocol in PROSPERO (registration number CRD42019133288). We selected seven eligible studies involving 619 patients for the final analysis.

RESULTS

The proportion of patients with local recurrence ranged from 20% to 100% in the curettage with preoperative denosumab group and ranged from 0% to 50% in the curettage-alone group. The odds ratio of local recurrence ranged from 1.07 to 37.80 in no more than 6 months of preoperative denosumab duration group and ranged from 0.60 to 28.33 in more than 6 months of preoperative denosumab duration group.

CONCLUSIONS

The available evidence for the benefit of denosumab in more aggressive giant cell tumors is inconclusive, and denosumab treatment may even be associated with an increase in the proportion of patients experiencing local recurrence. Because there are no randomized studies and the existing studies are of poor quality due to indication bias (the most aggressive Campanacci 3 lesions or those where even a resection would be difficult and result in morbidity are generally the patients who are treated with denosumab), the evidence to suggest a disadvantage is weak. Denosumab treatment should be viewed with caution until more definitive, randomized studies documenting a benefit (or not) have been conducted. Furthermore, we could not find evidence to suggest an appropriate length of preoperative denosumab before curettage.

Pre-operative denosumab is associated with higher risk of local recurrence in giant cell tumor of bone: a systematic review and meta-analysis

Background

In 2013, denosumab was introduced as peri-operative adjuvant treatment for giant cell tumor (GCT) of bone as it inhibits osteoclast activity. It is suggested that denosumab relives pain, facilitate curettage in lesions requiring resection initially. However, controversy remains whether denosumab increases the risk of local recurrence after surgery.

Methods

Medline, Embase and the Cochrane Library were comprehensively searched in June 2019 to identify studies investigating the clinical outcome of GCT of bone with and without peri-operative denosumab after surgery. Data were gathered and a meta-analysis was conducted.

Result

Ten studies with 1082 cases (169 in denosumab group, 913 in control group) were included. Overall, denosumab was associated with significantly higher risk of recurrence(P < 0.02) and inferior 5 year recurrence free survival(P = 0.000). Denosumab and curettage has a relatively higher risk of recurrence comparing to curettage alone(P = 0.07). The risk of recurrence is not significantly increased if denosumab was administered both preoperatively and postoperatively(P = 0.24).

Conclusion

Administration of denosumab is associated with increased risk of recurrence due to a variety of reasons, though it is proven effective in relieving pain, enabling curettage and improved functional outcome. Post-operative denosumab is recommended as it continuously suppress/eliminate residue tumor cells.

Overview of « druggable » alterations by histological subtypes of sarcomas and connective tissue intermediate malignancies

We summarize herein the literature data about molecular targeted therapies in sarcomas and conjunctive tissue intermediate malignancies. For each clinical setting, the level of evidence, the mechanism of action and the target are described. The two major axes include (i) identification of subgroups of tumors with druggable alteration irrespective of the histological diagnosis (e.g. NTRK), and (ii) druggable target of pathway related to the physiopathology of the tumor: denosumab and bone giant cell tumor, imatinib and soft tissue giant cell tumor, mTOR inhibitor and PECOMA.

[Giant cell tumor of bone : Morphology, molecular pathogenesis, and differential diagnosis]

The histological picture of giant cell tumor of bone is characterized by numerous osteoclast-like giant cells. However, these are not the actual tumor cells, but constitute a reactive infiltrate. Rather, the tumor cells are mononuclear mesenchymal cells, which even reveal an osteoblastic line of differentiation. The CD68-positive macrophages form the second group of mononuclear cells. The receptor activator of nuclear factor kappa-B/ligand (RANK/RANKL) system, which belongs to the tumor necrosis factor (TNF) cytokine family, is decisively involved in the activation of the giant cells. It is generally accepted that a RANKL expression of mononuclear stromal cells is responsible for the development and differentiation of osteoclast-like giant cells. Therefore, the RANKL inhibitor denosumab constituted an essential element for giant cell tumor therapy over the last several years, as it blocks the maturation of osteoclasts and thus the osteolytic activity and the spread of tumor. However, with time it became evident that the not risk-free therapy with denosumab may lead to extensive recurrences upon withdrawal, so this therapy is applied with caution today.At the molecular genetic level, the giant cell tumors of bone are characterized by point mutations in the H3F3A gene. The detection of this mutation is used for the diagnostic differentiation from other bone lesions containing giant cells. Giant cell osteosarcomas rarely contain H3F3A mutations. Chondroblastoma is characterized by mutations in the H3F3B gene.