Pulmonary metastasis of giant cell tumor of bones

Establishment and characterization of two novel patient-derived cell lines from giant cell tumor of bone: NCC-GCTB8-C1 and NCC-GCTB9-C1

Giant cell tumor of bone (GCTB) is a rare osteolytic bone tumor consisting of mononuclear stromal cells, macrophages, and osteoclast-like giant cells. Although GCTB predominantly exhibits benign behavior, the tumor carries a significant risk of high local recurrence. Furthermore, GCTB can occasionally undergo malignant transformation and distal metastasis, making it potentially fatal. The standard treatment is complete surgical resection; nonetheless, an optimal treatment strategy for advanced GCTB remains unestablished, necessitating expanded preclinical research to identify appropriate therapeutic options. However, only one GCTB cell line is publicly available from a cell bank for research use worldwide. The present study reports the establishment of two novel cell lines, NCC-GCTB8-C1 and NCC-GCTB9-C1, derived from the primary tumor tissues of two patients with GCTB. Both cell lines maintained the hallmark mutation in the H3-3A gene, which is associated with tumor formation and development in GCTB. Characterization of these cell lines revealed their steady growth, spheroid-formation capability, and invasive traits. Potential therapeutic agents were identified via extensive drug screening of the two cell lines and seven previously established GCTB cell lines. Among the 214 antitumor agents tested, romidepsin, a histone deacetylase inhibitor, and mitoxantrone, a topoisomerase inhibitor, were identified as potential therapeutic agents against GCTB. Conclusively, the establishment of NCC-GCTB8-C1 and NCC-GCTB9-C1 provides novel and crucial resources that are expected to advance GCTB research and potentially revolutionize treatment strategies.

A case report on pulmonary metastasis of giant cell tumor mimicking arteriovenous malformation

Giant cell tumor (GCT) is typically a benign tumor of the skeletal system that mainly presents with bone pain. Pulmonary metastasis is one of the distant presentations of GCT in patients who have previously undergone surgical resection of the tumor. Among the various presentations of pulmonary metastasis in GCT, lesions with arteriovenous malformation (AVM) features are rare and have only been reported in a few cases. In this case report, we present the case of a 29-year-old female patient who had previously undergone surgical resection of a GCT in her right lower extremity 4 years ago. The patient was referred to us with progressive dyspnea, and a lesion resembling an AVM was found during radiologic evaluation using chest computed tomography. Pathologic evaluation of the lesion after biopsy revealed that it was a metastasis of GCT presenting with vascular-like features in the lung. This study reports on a very rare occurrence of GCT pulmonary metastasis with an AVM appearance on imaging, highlighting the clinical importance of atypical presentations of pulmonary metastasis in patients with a history of GCT. Appropriate and timely screening and management of such lesions may prevent adverse outcomes such as massive hemorrhage and deterioration of lung function.

Non‑surgical outcomes and risk factors for pulmonary metastasis from giant cell tumor of bone

The present study detailed four factors associated with an increased risk of pulmonary metastasis, age, pathological fracture, local recurrence and mode of treatment. Local recurrence and pathological fracture were independent risk factors for developing metastasis. From January 2016 to December 2021, data from 50 patients diagnosed with giant cell tumor of bone (GCTB) treated in Khon Kaen Hospital, Thailand, were retrospectively analyzed. The risk factors, including age at diagnosis, location of GCTB, clinical presentation, Campanacci stage and no. of local recurrences, for GCTB-induced pulmonary metastasis were evaluated using univariate and multivariable logistic regression analyses. Of the 50 patients analyzed, 9 patients (18%), with a mean age of 46.3 years (range, 18-68 years), developed pulmonary metastasis. No patients died from pulmonary metastasis in the present study. Statistically significant associations were observed between the development of metastasis and both clinical fracture [odds ratio (OR), 6.107; 95% confidence interval (CI), 1.08-34.70] and local recurrence (OR, 6.48; 95% CI, 1.03-40.87). Patients presenting with both a clinical fracture and local tumor recurrence require more rigorous clinical observation due to the significantly elevated risk of disease progression.

Tetraploidization Increases the Motility and Invasiveness of Cancer Cells

Polyploidy and metastasis are associated with a low probability of disease-free survival in cancer patients. Polyploid cells are known to facilitate tumorigenesis. However, few data associate polyploidization with metastasis. Here, by generating and using diploid (2n) and tetraploid (4n) clones from malignant fibrous histiocytoma (MFH) and colon carcinoma (RKO), we demonstrate the migration and invasion advantage of tetraploid cells in vitro using several assays, including the wound healing, the OrisTM two-dimensional cell migration, single-cell migration tracking by video microscopy, the Boyden chamber, and the xCELLigence RTCA real-time cell migration. Motility advantage was observed despite tetraploid cell proliferation weakness. We could also demonstrate preferential metastatic potential in vivo for the tetraploid clone using the tail vein injection in mice and tracking metastatic tumors in the lung. Using the Mitelman Database of Chromosome Aberrations in Cancer, we found an accumulation of polyploid karyotypes in metastatic tumors compared to primary ones. This work reveals the clinical relevance of the polyploid subpopulation and the strategic need to highlight polyploidy in preclinical studies as a therapeutic target for metastasis.

Imaging of Lower Limb Tumors and Tumor-Like Conditions

Bone and soft tissue lesions are frequently seen in the lower limbs. Many are non-neoplastic but may mimic tumours. In this article, we discuss a practical approach for the diagnosis and management of the most common tumours and tumour-like conditions seen in the lower limbs.

Is three-dimension-printed mesh scaffold an alternative to reconstruct cavity bone defects near joints?

PURPOSE

Reconstruction of cavity bone defects after curettage of benign bone tumours around the joint remains challenging. We designed a novel 3D-printed mesh scaffold as a substitute for bone cement, aiming to support the articular surface, protect the subchondral bone, and reduce complication rates.

METHODS

We retrospectively analyzed seven patients who received curettage and reconstruction using a 3D-printed mesh scaffold between January 2020 and June 2021. Pain and function were evaluated using the 10-cm Visual Analogue Scale (VAS) score and the 1993 version of the Musculoskeletal Tumor Society (MSTS-93) score. Radiographs were used to evaluate articular surface supporting, subchondral bone protection, and complications.

RESULTS

The median functional MSTS-93 and VAS scores were both improved after surgery, and the median 3D-printed mesh scaffold volume was smaller than the median defect volume. Articular surface supporting, subchondral bone preservation, and osteogenesis were observed post-operatively. No related complications were observed during the last follow-up.

CONCLUSIONS

The 3D-printed mesh scaffold provided sufficient mechanical support for the articular surface and protected the subchondral bone. We recommended the 3D-printed mesh structure as an alternative to repair cavity bone defects around joints.

Giant Cell Tumor of the Triquetrum: Clinical Case and Literature Review

Giant cell tumor (GCT) is a benign, locally aggressive neoplasm with little incidence at the carpal bone level. We present a case of pyramidal bone GCT that required open biopsy for diagnosis. As a definitive treatment, en bloc resection of the pyramidal bone and luno-capitate arthrodesis were performed to avoid frequent relapses of these neoplasms and ensure proper functionality of the anatomical segment.

Siglec-15 as a New Perspective Therapy Target in Human Giant Cell Tumor of Bone

The main features of a giant cell tumor of bone (GCTB) are frequent recurrence and aggressive osteolysis, which leads to a poor prognosis in patients. Although the treatment methods for a GCTB, such as scraping and resection, effectively inhibit the disease, the tendency toward malignant transformation remains. Therefore, it is important to identify new treatment methods for a GCTB. In this study, we first found high Siglec-15 expression in GCTB tissues, which was significantly associated with Campanacci staging and tumor recurrence. In Spearman's analysis, Siglec-15 expression was significantly correlated with Ki-67 levels in tumor tissues. In vitro, the mRNA and protein levels of Siglec-15 were high in GCTB stromal cells (Hs737. T), and Siglec-15 knockdown inhibited the biological characteristics of GCTB stromal cells. The RNA sequencing results enabled a prediction of the downstream genes by using the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and MCODE analyses, and the findings showed that CXCL8 was significantly regulated by Siglec-15 and might be a promising downstream target gene of Siglec-15. Therefore, Siglec-15 may be a potential immunotherapy target for a GCTB.

A Retrospective Audit of Demography and Different Surgical Modalities Adopted for Giant Cell Tumor of Bone in Eastern India

Background and objective

There is scarce data on demography and different surgical treatment modalities for giant cell tumor of bone (GCTB) from eastern India. In light of this, the present study aimed to examine the demographic characteristics, different surgical treatment modalities, and recurrence rate of GCTB at a tertiary care institute in Bihar.

Materials and methods

A retrospective audit of 52 GCTB patients who were treated at the center from January 2016 to December 2020 was conducted. The minimum follow-up period was one year. GCTB patients underwent surgical procedures ranging from extended intralesional curettage with bone graft or bone cement with or without fixation to wide local excision to resection with or without reconstruction or amputation depending on the stage and site of the tumors.

Results

The mean age of patients was 31.86 years (range: 13-67 years). The distal femur (20 patients, 38.46%) and proximal tibia (11 patients, 21.15%) were the most common sites of the tumor. Sixty-eight confirmed cases (male: 32, female: 36) of GCTB were operated on, with a male-to-female ratio of 1:1.125. Sixteen patients (four males and 12 females) were lost to follow-up. So, the final study consisted of 52 patients with a median age of 28 years (first quartile: 24 years, third quartile: 38 years). The majority of patients (32 patients, 61.53%) were in the third and fourth decades of life.

Conclusion

Based on this retrospective audit, it is concluded that the knee region is the most common site of GCTB. Surgery is the mainstay of management. Most of the patients came under Campanacci Grade 3 with low compliance with follow-up and adherence to the treatment. Hence, educational programs, the establishment of early detection centers, and timely referral to expert treatment are necessary.

Outcomes in Bone Giant Cell Tumors Treated With Surgical Resection With and Without Denosumab Injection: A Single-Institution Retrospective Study

Background: Giant cell tumors of the bone (GCTB) are rare, benign, aggressive, recurrent tumors that are most often found at the ends of long bones. They account for 5% of all primary bone tumors and 20% of all benign bone tumors. The clinical features of GCTB include local swelling, pain, and limitations in joint movement. Approximately half of GCTB arise around the knee joint, affecting either the distal femur or proximal tibia. Tissue biopsy reveals an excess of multinucleated giant cells on a stromal cell background, indicating a diagnosis. Intralesional curettage is used to treat GCTB and is associated with minimal disability; however, local recurrence may occur in many patients. Resection and endoprosthetic repair or bone graft reconstruction are often used to treat GCTB near the joint. To our knowledge, there are currently no studies on this topic in the city of Jeddah, where we conducted our study. Our aim was to evaluate the outcome of surgical resection accompanied by denosumab injection compared to that of surgery alone in treating GCTB.

Methods: All cases of GCTB at King Abdulaziz Medical City, Jeddah, between January 2008 and December 2018, that fulfilled the inclusion and exclusion criteria were included. All cases of GCTB in the pre-specified period were classified as surgical resection with denosumab injection or surgical resection alone. The outcomes of the two modalities were compared. Recurrence was investigated in patients belonging to both the groups.

Results: Twenty-six cases that met the inclusion criteria were included in the study and the data were analyzed. The subjects were divided into two groups: denosumab and surgery (n = 7) and surgery alone (n = 19). Patients treated with denosumab and surgery had a higher recurrence rate (57%); however, the difference was not significant (p = 0.407).

Conclusion: Our study showed that when comparing local recurrence after curettage in patients treated with denosumab and patients who did not receive it, preoperative denosumab therapy was associated with an increased incidence of local recurrence. We recommend a systematic review that can include more studies in this field to acquire more definitive results regarding this topic.

Secondary Malignancy in Giant Cell Tumor: A Single-Center Study

Giant cell tumor of bone (GCTB) undergoes a sarcomatous transformation. Secondary malignancy in giant cell tumor (MGCT) is associated with radiotherapy and has a dismal prognosis. We reviewed medical records to investigate the clinicopathological characteristics and prognosis of MGCT patients. The enrollment criterion was high-grade spindle-cell sarcoma, which developed at the site of prior GCTB treatment. Twelve patients were analyzed: six females and six males. The median age was 42.5 years. Benign recurrence occurred in five GCTB patients not treated with radiotherapy. No pulmonary implants were observed. The median latency to the malignant transformation was 63 months. Nine patients were AJCC stage IIB, and three were stage IVA. The median follow-up period after malignant transformation was 62.5 months. Five patients developed local recurrence, and six had distant metastasis. Five-year overall recurrence and metastasis-free survival rates were 61.9%, 66.7%, and 58.3%, respectively. Initial metastasis was a predictive factor for overall survival. Benign local recurrence of GCTB was also a negative factor for metastasis-free survival of MGCT patients. Differences in overall survival according to benign recurrence also showed a tendency toward significance. In our series, secondary MGCT did not occur after radiotherapy. The prognosis was better than previous findings. Benign recurrence of GCTB could reflect the prognosis of MGCT.

Epigenetic lockdown of CDKN1A (p21) and CDKN2A (p16) characterises the neoplastic spindle cell component of giant cell tumours of bone

Giant cell tumour of bone (GCTB) comprises the eponymous osteoclastic multinucleated giant cells eliciting bone lysis, a H3F3A-mutated neoplastic mononucleated fibroblast-like cell population and H3F3A-wild type mononucleated stromal cells. In this study, we characterised four new cell lines from GCTB. Furthermore, we compared the genome-wide DNA methylation profile of 13 such tumours and three further cell lines with giant cell rich lesions comprising three H3F3B-mutated chondroblastomas, three USP6-rearranged aneurysmal bone cysts, three non-ossifying fibromas, two hyperparathyroidism-associated brown tumours as well as mesenchymal stem cells, osteoblasts, and osteoclasts. In an unsupervised analysis, we delineated GCTB and chondroblastomas from the other analysed tumour entities. Using comparative methylation analysis, we demonstrated that the methylation pattern of the cell lines approximately equals that of H3F3A-mutated stromal cells in tissue. These patterns more resemble that of osteoblasts than that of mesenchymal stem cells, which argues for the osteoblast as the cell of origin of giant cell tumours of bone. Using enrichment analysis, we detected distinct hypermethylated clusters containing histone and collagen genes as well as target genes of the tumour suppressor p53. We found that the promotor regions of CDKN1A, CDKN2A and IGFBP3 are methylated more strongly in GCTB than in the other giant cell containing lesions, mesenchymal stem cells, osteoblasts, and osteoclasts (p<0.001). This hypermethylation correlates with the lower gene expression at the mRNA level for these three genes in the cell lines, the lack of p16 and p21 in these cell lines and the lower expression of p16 and p21 in GCTB. Overall, our analysis reveals characteristic DNA methylation patterns of giant cell tumours of bone and chondroblastomas and shows that cell lines of giant cell tumours of bone are a valid model for further analysis of H3F3A-mutated tumour cells. This article is protected by copyright. All rights reserved.

Resultados da curetagem estendida com e sem aloenxerto ósseo para tumores de células gigantes de grau II no joelho. Um estudo comparativo retrospectivo

Objetivo Este é o primeiro estudo a estabelecer a utilidade da curetagem estendida com ou sem enxerto ósseo em tumores de células gigantes (TCGs) de grau II na articulação do joelho com o objetivo de explorar os resultados funcionais pós-operatórios.

Métodos Revisamos retrospectivamente 25 casos de TCGs de grau II de Campanacci submetidos a curetagem estendida entre janeiro de 2014 e dezembro de 2019. Os participantes foram divididos em 2 grupos: um grupo de 12 pacientes foi submetido a curetagem estendida com aloenxerto ósseo e cimento ósseo, enquanto o outro grupo, com 13 pacientes, foi submetido a curetagem estendida apenas com cimento ósseo. A qualidade de vida foi avaliada pela Pontuação Revista da Musculoskeletal Tumor Society (MTS, na sigla em inglês) e pela Pontuação da Knee Society (KS, na sigla em inglês), enquanto as taxas de recidiva e complicações foram avaliadas em cada coorte na última consulta de acompanhamento. O teste de Fisher e os testes t de duas amostras foram usados para comparação de resultados categóricos e contínuos, respectivamente

Resultados A média de idade dos pacientes foi de 28,09 (7,44) anos; 10 (40%) pacientes eram do sexo masculino e 15 (60%) pacientes eram do sexo feminino. O fêmur distal e a tíbia proximal foram acometidos em 13 (52%) e 12 (48%) dos pacientes, respectivamente. Não houve diferença significativa na pontuação revista da MTS (25,75 versus 27,41; p = 0,178), na pontuação da KS (78,67 versus 81,46; p = 0,33) e nas taxas de recidiva (0 versus 0%; p = 1) e complicações (25 versus 7,69%; p = 0,21).

Conclusões A curetagem estendida com ou sem aloenxerto ósseo tem resultados funcionais semelhantes em pacientes com TCGs de grau II no joelho, sem qualquer diferença importante na incidência de recidivas e complicações. No entanto, a conveniência cirúrgica e o custo-benefício podem favorecer a utilização apenas de cimento ósseo, enquanto a prevenção da osteoartrite em longo prazo precisa ser investigada para favorecer o enxerto ósseo.

Giant Cell Tumor of Bone Versus Tenosynovial Giant Cell Tumor - Similarities and Differences

Giant cell tumor of bone (GCTB) and tenosynovial giant cell tumor (TGCT) share misleadingly similar names, soft texture and brown color macroscopically, osteoclast-like multinucleated giant cells microscopically and localisation in the musculoskeletal system. However, these two tumor types are biologically and clinically two distinct entities with different natural courses of progression and considerably different modes of surgical and medical treatment. In this article, we provide a detailed update on the similarities and the differences between both tumor types.GCTB is a locally aggressive osteolytic bone tumor, commonly seen in patients in their third decade of life. It usually occurs as a solitary lesion in the meta-epiphyseal region of long bones. It can be diagnosed using plain radiographic imaging, CT radiography or MRI to estimate the tumor extent, soft tissue and joint involvement. GCTB is usually treated with intralesional excision by curettage. Systemically, it can be treated with bisphosphonates and denosumab or radiotherapy.TGCT is a rare, slowly progressing tumor of synovial tissue, affecting the joint, tendon sheath or bursa, mostly seen in middle-aged patients. TGCT is usually not visible on radiographs and MRI is mostly used to enable assessment of potential bone involvement and distinguishing between two TGCT types. Localised TGCT is mostly treated with marginal surgical resection, while diffuse TGCT is optimally treated with total synovectomy and is more difficult to remove. Additionally, radiotherapy, intraarticular injection of radioactive isotopes, anti-TNF-α antibodies and targeted medications may be used.

Recurrent Giant Cell Tumor of Distal Radius with Pulmonary Metastasis: A Case Report

Introduction

Giant cell tumor (GCT) is a rare, locally aggressive tumor of bone characterised by the presence of abundant giant cells. GCT has a tendency for recurrence, occurring in approximately a quarter of cases. GCT very rarely metastasize, with metastasis to lungs being reported in approximately 1% of GCTs.

Case Presentation

A 48 year -year-old gentleman noticed a swelling around his left wrist. Radiograph showed a lytic lesion in the distal radius having typical soap bubble appearance. He underwent left distal radius curettage and bone cement placement. The histopathological examination of excised tissue confirmed the diagnosis of GCT. Patient then had recurrence of the tumor 6 months after the surgery. He underwent left distal radius resection, fibular grafting, and wrist arthrodesis. Resected tissue on histopathological examination showed features consistent with GCT. One year later, patient noticed multiple swellings in the region of his left wrist. On examination, there were multiple bony hard, non-tender swellings over the distal forearm. Radiographs revealed a lytic lesion in the fibular strut graft with breach of the cortex. Patient was diagnosed to have recurrence for GCT for the second time. Chest radiograph and Computed Tomography (CT) scan of the thorax revealed multiple canon ball lesions in bilateral lungs, suggesting a metastasis of GCT. The patient, however, did not have any respiratory complaints. We then performed an excision of the tumor, removal of plate and k-wire, and applied a wrist spanning external fixator. Histopathological examination confirmed a recurrence of GCT. The patient was not willing for metastasectomy. The patient was followed up for a period of 18 months. We found no clinical, radiological evidence of recurrence. The metastatic lesions in the lungs were not found to have increased in number or size, while the patient remained asymptomatic.

Conclusion

Giant cell tumours are benign, however, they have a propensity for recurrence. Recurrent GCT are more likely to lead to pulmonary metastasis, and thus warrant pulmonary evaluation. Pulmonary metastasis has a favourable outcome with only half the cases having progression.

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.

Reconstruction and repair, using mini-plate and bone graft for persons living with HIV with giant cell tumor of long bone: retrospective analysis of a single-center experience

Background

To evaluate the effect of reconstruction and repair, using a mini-plate and bone graft for HIV -positive patients with giant cell tumor of long bone.

Methods

We conducted a retrospective analysis of 12 HIV positive patients with giant cell tumor of long bone. A non-HIV-positive cohort of patients, matched for age, sex, and disease type, was selected as the control group. From June 2012 to August 2020, curettage by ultrasonic scalpel was performed in all patients, combined with min- plate and bone graft treatment. All patients were followed- up for 18 to 60 months. Limb function was evaluated, using the MSTS93 scoring system, and any examples of postoperative recurrence, distant metastasis, complications, MSTS93 score, and fracture prognosis were recorded.

Results

The mean age of HIV group was 43.5 years. The ratio of men to women was 11: 1. In all cases the histopathological diagnosis was clear, except the patients with primary malignant giant cell tumor of bone, including five, three, two, and two cases in the proximal tibia, distal femur, distal tibia, and talus, respectively. Following their surgery, all patients were followed up with an average of 31.24 ± 11.84 months. No local recurrence or pulmonary metastases were observed. Post-surgery, all the 12 patients showed good bone morphologic repair and reconstruction, good bone healing, good joint function, and no pathological fractures around their lesion. In the HIV group, one case of giant cell tumor in the proximal tibia showed mild articular surface collapse and mild valgus deformity of the knee joint but retained good joint function. The MSTS scores of excellent or good in the two groups comprised 83.3%, thus, there was no significant difference between them (P > 0.05). Compared with preoperatively, the MSTS scores in the HIV group were significantly improved, ranging from 7 to 11 points preoperatively to 24 to 27 points postoperatively; this difference was statistically significant (P < 0.05).

Conclusion

Reconstruction and repair, using a mini-plate and bone graft for HIV -positive patients with giant cell tumor of long bone can achieve satisfactory results. The mini- plate requires little space and is flexible during reconstruction and fixation, significantly reducing complications such as surgical site infection, as well as preserving joint function and avoiding amputation; therefore, it is a safe and effective treatment method.

Risk factors and oncological outcomes of pulmonary metastasis in patients with giant cell tumor of bone

BACKGROUND

Giant cell tumor (GCT) of bone has a rare potential for metastatic spread. This study aimed at evaluating the incidence of chest metastases in GCT and their oncological outcome and identifying possible risk factors.

METHODS

Medical records of 466 (313 de novo and 153 recurrent) patients with primary GCT of bone were retrospectively reviewed. Fifteen (3.2%) patients developed chest metastasis. Time from diagnosis of the primary bone lesion to the diagnosis of metastasis, treatment modalities of metastasis, and the course of treatment were revised. The functional outcome was evaluated using the Musculoskeletal Tumor Society (MSTS) scoring system, and postoperative complications were recorded.

RESULTS

This study included 7 males and 8 females with a mean age of 27.3 ± 7.9 years. The most common site of the primary tumor was the distal femur. All fifteen patients were recurrent cases. The mean follow-up period was 67.7 ± 33.2 months. Chest metastasis was diagnosed after a mean time of 28.1 ± 28.9 months from the initial diagnosis of the bone lesion. One patient died of disease (DOD) 18 months after the surgical intervention. The incidence of chest metastasis in recurrent cases was 9.8%, while de novo cases did not develop chest metastasis, P < 0.001. Previous curettage was associated with a higher incidence of chest metastasis (14.6%) compared to previous resection (4.2%), P = 0.03.

CONCLUSIONS

Chest metastasis following GCT of bone is rare. Risk factors include recurrent cases, especially following previous curettage. Patients have a good prognosis and a low mortality rate.

LEVEL OF EVIDENCE

Level IV, retrospective.

Aberrant sphingomyelin 31P-NMR signatures in giant cell tumour of bone

An understanding of the biochemistry of the giant cell tumour of bone (GCTB) provides an opportunity for the development of prognostic markers and identification of therapeutic targets. Based on metabolomic analysis, we proposed glycerophospholipid metabolism as the altered pathway in GCTB and the objective of this study was to identify these altered metabolites. Using phosphorus-31 nuclear magnetic resonance spectroscopy (³¹P-NMR), sphingomyelin was determined as the most dysregulated phospholipid in tissue samples from six patients with GCTB; subsequently, enzymes related to its biosynthesis and hydrolysis were examined using immunodetection techniques. High expression of sphingomyelin synthases 1 and 2, but low expression of neutral sphingomyelinase 2 (nSMase2), was found in GCTB tissues compared to non-neoplastic bone tissues. Sphingomyelin/ ceramide biosynthesis is dysregulated in GCTB due to alterations in the expression of SMS1, SMS2, and nSMase2.

Response to Denosumab in 2 Children With Recurrent Giant Cell Tumor of the Bone With Pulmonary Metastasis

Giant cell tumor of the bone (GCTB) is an uncommon bone tumor, usually localized, and rarely presents at <20 years of age. Denosumab, a fully human monoclonal antibody against RANKL (receptor activator of nuclear factor κB ligand), is approved for the treatment of unresectable GCTB in skeletally mature individuals. We present a case series of 2 pediatric patients with recurrent GCTB with pulmonary metastasis, with clinical response to denosumab therapy.

The role of Denosumab in joint preservation for patients with giant cell tumour of bone

AIMS

Local recurrence remains a challenging and common problem following curettage and joint-sparing surgery for giant cell tumour of bone (GCTB). We previously reported a 15% local recurrence rate at a median follow-up of 30 months in 20 patients with high-risk GCTB treated with neoadjuvant Denosumab. The aim of this study was to determine if this initial favourable outcome following the use of Denosumab was maintained with longer follow-up.

METHODS

Patients with GCTB of the limb considered high-risk for unsuccessful joint salvage, due to minimal periarticular and subchondral bone, large soft tissue mass, or pathological fracture, were treated with Denosumab followed by extended intralesional curettage with the goal of preserving the joint surface. Patients were followed for local recurrence, metastasis, and secondary sarcoma.

RESULTS

A total of 25 patients with a mean age of 33.8 years (18 to 67) with high-risk GCTB received median six cycles of Denosumab before surgery. Tumours occurred most commonly around the knee (17/25, 68%). The median follow-up was 57 months (interquartile range (IQR) 13 to 88). The joint was salvaged in 23 patients (92%). Two required knee arthroplasty due to intra-articular fracture and arthritis. Local recurrence developed in 11 patients (44%) at a mean of 32.5 months (3 to 75) following surgery, of whom four underwent repeat curettage and joint salvage. One patient developed secondary osteosarcoma and another benign GCT lung metastases.

CONCLUSION

The use of Denosumab for joint salvage was associated with a higher than expected rate of local recurrence at 44%. Neoadjuvant Denosumab for joint-sparing procedures should be considered with caution in light of these results. Cite this article: Bone Joint J 2021;103-B(1):184-191.

Drivers underpinning the malignant transformation of giant cell tumour of bone

The rare benign giant cell tumour of bone (GCTB) is defined by an almost unique mutation in the H3.3 family of histone genes H3‐3A or H3‐3B; however, the same mutation is occasionally found in primary malignant bone tumours which share many features with the benign variant. Moreover, lung metastases can occur despite the absence of malignant histological features in either the primary or metastatic lesions. Herein we investigated the genetic events of 17 GCTBs including benign and malignant variants and the methylation profiles of 122 bone tumour samples including GCTBs. Benign GCTBs possessed few somatic alterations and no other known drivers besides the H3.3 mutation, whereas all malignant tumours harboured at least one additional driver mutation and exhibited genomic features resembling osteosarcomas, including high mutational burden, additional driver event(s), and a high degree of aneuploidy. The H3.3 mutation was found to predate the development of aneuploidy. In contrast to osteosarcomas, malignant H3.3‐mutated tumours were enriched for a variety of alterations involving TERT, other than amplification, suggesting telomere dysfunction in the transformation of benign to malignant GCTB. DNA sequencing of the benign metastasising GCTB revealed no additional driver alterations; polyclonal seeding in the lung was identified, implying that the metastatic lesions represent an embolic event. Unsupervised clustering of DNA methylation profiles revealed that malignant H3.3‐mutated tumours are distinct from their benign counterpart, and other bone tumours. Differential methylation analysis identified CCND1, encoding cyclin D1, as a plausible cancer driver gene in these tumours because hypermethylation of the CCND1 promoter was specific for GCTBs. We report here the genomic and methylation patterns underlying the rare clinical phenomena of benign metastasising and malignant transformation of GCTB and show how the combination of genomic and epigenomic findings could potentially distinguish benign from malignant GCTBs, thereby predicting aggressive behaviour in challenging diagnostic cases. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Sacral tumours and their mimics: pictorial review and diagnostic strategy

Sacral tumours encompass an extensive range of differential diagnosis. The clinical presentation is often non-specific, including neurological deficits and low back pain. Accurate diagnosis of sacral lesions is challenging and requires a comprehensive imaging strategy and robust knowledge on the imaging characteristics of different pathological processes. This review will provide an updated overview of the computed tomography (CT), magnetic resonance imaging (MRI), and integrated positron-emission tomography (PET)-CT features of some common and rare sacral tumours and their mimics. Several clinical scenarios with specific diagnostic considerations and treatment implications will be described.

Radiological Features of Giant Cell Tumours of Bone

Introduction

The aim of this study was to evaluate radiological measurements to establish the origin of giant cell tumours of bone.

Methods

A multi-centre retrospective review was conducted of patients with histologically confirmed giant cell tumours of bone. Images were analysed to estimate the centre of the tumour. Measured from the joint line, the ratio between the distance of the centre of the tumour and the physeal scar was calculated.

Results

Ninety-five patients were included in the study. Two observers found the tumour to be arising from the metaphyseal area in 94% - 97% of the cases. There was good agreement between the measurements of observers (interclass correlation coefficient 0.71).

Conclusion 

Giant cell tumours of bone appear to be arising from the metaphyseal region.

Benign albeit glycolytic: MCT4 expression and lactate release in giant cell tumour of bone

Giant cell tumour of bone (GCTB) is a histologically benign, locally aggressive skeletal lesion with an unpredictable propensity to relapse after surgery and a rare metastatic potential. The microscopic picture of GCTB shows different cell types, including multinucleated giant cells, mononuclear cells of the macrophage-monocyte lineage, and spindle cells. The histogenesis of GCTB is still debated, and morphologic, radiographic or molecular features are not predictive of the clinical course. Characterization of the unexplored cell metabolism of GCTB offers significant clues for the understanding of this elusive pathologic entity. In this study we aimed to characterize GCTB energetic metabolism, with a particular focus on lactate release and the expression of monocarboxylate transporters, to lie down a novel path for understanding the pathophysiology of this tumour. We measured the expression of glycolytic markers (GAPDH, PKM2, MCT4, GLUT1, HK1, LDHA, lactate release) in 25 tissue samples of GCTB by immunostaining and by mRNA and ELISA analyses. We also evaluated MCT1 and MCT4 expression and oxidative markers (JC1 staining and Bec index) in tumour-derived spindle cell cultures and CD14+ monocytic cells. Finally, we quantified the intratumoural and circulating levels of lactate in a series of 17 subjects with GCTB. In sharp contrast to the benign histological features of GCTB, we found a high expression of glycolytic markers, with particular reference to MCT4. Unexpectedly, this was mainly confined to the giant cell, not proliferating cell component. Accordingly, GCTB patients showed higher levels of blood lactate as compared to healthy subjects. In conclusion, taken together, our data indicate that GCTB is characterized by a highly glycolytic metabolism of its giant cell component, opening new perspectives on the pathogenesis, the natural history, and the treatment of this lesion.

Giant Cell Tumor of the Calcaneus

A 17-year-old female presented to us with pain and swelling in the right heel. Examination revealed the swelling to be tender, hard and fixed to the calcaneus. Radiographs showed an expansile, lytic lesion of the calcaneus with well-defined margins and no extraosseus spread. A core biopsy was done which showed multinucleated giant cells in a sea of mononuclear stromal cells, suggestive of a giant cell tumour (GCT). Curettage and filling up of the defect with bone cement was done under anaesthesia. The patient was fully ambulatory three months after the surgery. At two-year follow-up, the patient continued to be asymptomatic and radiographs revealed no signs of recurrence. It is important to note that GCT can occur in these rare sites and unusual age groups, and hence requires a good level of awareness of the surgeon and adequate preoperative workup, including biopsy, before proceeding to the definitive treatment of the lesion. Considering its potential local aggressiveness, early intervention is necessary. The patient should be kept under regular follow-up to detect any recurrence or metastasis in early stage.

[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.

Simvastatin Possesses Antitumor and Differentiation-Promoting Properties That Affect Stromal Cells in Giant Cell Tumor of Bone

Giant cell tumor of bone (GCTB) is a locally aggressive destructive bone lesion. The management of pulmonary metastasis and local recurrence after the surgical treatment of GCTB remains a challenge. Pathologically, stromal cells in GCTB are known as primary neoplastic cells and are recognized as incompletely differentiated preosteoblasts. Therefore, inducing GCTB stromal cells to differentiate into cells with a mature osteoblastic phenotype may stop tumor growth and recurrence. In this study, we aimed to investigate how simvastatin, a clinically approved and commonly used statin that has been known to promote the maturation of cells of the osteogenic lineage, affects GCTB stromal cells. We found that simvastatin effectively inhibited cell viability by suppressing proliferation and by inducing apoptosis in GCTB stromal cells. Moreover, simvastatin treatment upregulated the expression of genes related to osteogenic maturation, such as runt-related transcription factor 2, osteopontin, and osteocalcin, and increased the mineralization of the extracellular matrix in GCTB stromal cells. Ingenuity pathway analysis was used to discover that the vitamin D receptor pathway was involved in the simvastatin-induced osteogenic differentiation of GCTB stromal cells by upregulating the 1,25-dihydroxyvitamin D metabolism. Taken together, this in vitro study demonstrates the antitumor and differentiation-promoting effects of simvastatin on GCTB stromal cells and suggests the possibility of using simvastatin as an adjuvant therapy for GCTB. These findings support further clinical investigation of the efficacy of using simvastatin as an adjuvant therapy for GCTB to reduce recurrence and distant metastasis after surgical treatment. © 2019 Orthopedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:297-310, 2020.

Giant cell tumor of bone: Unusual features of a rare tumor

Giant cell tumor of bone is a benign tumor with an aggressive behavior. Its typical subarticular location and high recurrence risk can be associated with significant morbidity. Although benign, it can rarely metastasize especially to the lungs. Also, it can be multicentric in less than 1% of patients. Late malignant transformation, although rare, can occur with a very poor prognosis. This series reports on these unusual and challenging features and management considerations of giant cell tumor of bone. This retrospective study included review of the medical records of patients with a confirmed histopathological diagnosis of giant cell tumor of bone. A total of 25 patients (16 females and 9 males) with a mean age of 34.5 years were included; 22 had primary tumors, while 3 were referred with recurrent tumors. Pain was the most common presenting symptom. Most patients had grade III tumors. Tumors around the knee were the most common. Multicentric tumors were detected in three patients. Twenty-three patients (20 primary giant cell tumor of bone and 3 with recurrence) received treatment. Most patients (15/23) were treated with intralesional curettage with or without adjuvants. Seven patients had wide excision. Recurrence was seen in 45% (9/20) of primary giant cell tumor of bone especially with difficult anatomical locations. Most recurrences occurred more than 4 years after treatment. Pulmonary nodules were detected in four patients; two of them showed resolution during follow-up. One patient developed secondary sarcoma transformation with a fatal outcome. Giant cell tumor of bone was more common in females. Long bones were more affected, especially around the knee. Intralesional curettage was the most frequently used treatment. Recurrence was associated with inadequate tumor resection (especially in difficult anatomical location), younger age, male gender, and advanced local tumor grade. Denosumab can be used in the treatment of pulmonary metastasis, multicentric and recurrent giant cell tumor of bone. Due to late recurrence and malignant transformation, a prolonged follow-up is warranted.

[New aspects on giant cell tumor of bone]

A giant cell tumor of bone (GCTB) is one of the giant cell-rich lesions of bone and has to be differentiated from non-ossifying fibroma, aneurysmatic bone cyst, chondroblastoma, "brown tumor" and osteosarcoma containing giant cells. A hallmark of GCTB is the presence of the distinct histone 3 (H3F3A) mutation G34W and its detection either by sequencing methods or using immunohistochemistry with a novel antibody against this mutational site. Worrisome is the fact that under denosumab therapy a histological change of the lesions can be seen and there are first reports of sarcomas arising after therapy. When diagnosing giant cell-rich lesions, pathologists should be aware of the various differential diagnoses and morphological spectrum within GCTB.

Retrospective analysis of 51 intralesionally treated cases with progressed giant cell tumor of the bone: local adjuvant use of hydrogen peroxide reduces the risk for tumor recurrence

BACKGROUND

Giant cell tumor of the bone (GCT) has high local recurrence rates and the prognosis is hard to predict. We therefore retrospectively analyzed clinical outcome and recurrences of 51 GCT cases focusing on the effects of adjuvant local use of hydrogen peroxide.

METHODS

The series enclosed 51 advanced GCT cases of the upper and lower extremities (n = 27 Campanacci grade III; n = 24 grade II; n = 39 surgery at our institution, n = 12 elsewhere). Mean follow-up was 88.3 (± 62.0) months. Surgical details, histology, metastases, recurrences, and interview-based data on satisfaction and function including the Musculoskeletal Tumor Society (MSTS) score were evaluated. It was investigated whether hydrogen peroxide was additionally used or not to clean the tumor cavity after curettage as we hypothesized influence on recurrences. To analyze the underlying mechanisms, GCT-derived stromal cell lines were cultured in vitro and tested for cell viability and apoptosis after treatment with hydrogen peroxide. Statistical analysis was performed with Student's t tests, analysis of variance (ANOVA) with post hoc testing, Mann-Whitney U tests, chi-square tests, Kaplan-Meier analysis, and multivariate Cox regression analysis.

RESULTS

The whole series had 21 recurrences (41%). Eleven recurrences were found (28%) after surgery at our institution. Kaplan-Meier analysis of cumulative recurrence-free survival revealed at 2 years follow-up 69% (72%, only our institution) and at 10 years follow-up 54% (68%, only our institution). Intralesional resection was performed by vigorous curettage, burring, and defect filling with either polymethylmethacrylate bone cement (n = 45) or cancellous bone from the iliac crest (n = 6). Univariate chi-square analysis showed significantly lower recurrence rate after bone cement filling (2.3-fold, p = 0.024). Cleaning of the lesion cavity with hydrogen peroxide significantly reduced recurrence rate (whole collective 2.9-fold, p = 0.004; our institution 2.8-fold, p = 0.04) and significantly increased cumulative recurrence-free survival rate (whole collective at 10 years follow-up 74% versus 31%, p = 0.002; our institution 79% versus 48%, p = 0.02) compared to cases without hydrogen peroxide treatment. In multivariate analysis, significant risk factors for recurrence were pathological fracture (hazard ratio 3.7; p = 0.04), high mitosis rate (hazard ratio 15.6; p = 0.01), and lack of hydrogen peroxide use (hazard ratio 6.0; p = 0.02). In vitro cell culture analyses found apoptotic nature of hydrogen peroxide induced GCT cell death.

CONCLUSIONS

The present series proved for the first time that additional cleaning of the tumor cavity with hydrogen peroxide before defect filling significantly reduced recurrence rate and significantly increased recurrence-free survival in advanced but intralesionally treated GCT cases.

Increased Risk of Lung Metastases in Patients with Giant Cell Bone Tumors: A Systematic Review

Giant cell tumors of the bone are rare, usually benign, tumors consisting of large, multinucleated bone cells. Remarkably, these tumors are characterized by aggressive growth. They tend to recur frequently and, in rare cases, metastasize to the lungs. Previous studies tried to identify risk factors for lung metastasis by giant cell bone tumors. Those studies reported different results due to a small number of patients. Therefore, a particularly high risk associated with this type of bone tumor prompted this systematic review and meta-analysis to identify risk factors for the development of lung metastases. The risk factors for lung metastasis by giant cell bone tumors searched for in this study were gender, age, lung metastasis and recurrence period, follow-up time, primary or recurrent tumor, Campanacci grading, tumor localization, disease course, treatment of primary and recurrent tumors, and pulmonary metastases treated by surgery, radiation, and chemotherapy. This meta-analysis identified the features outlined above by comparing the groups of patients with giant cell bone tumors and lung metastases with the control group consisting of patients without lung metastases. The search for suitable studies revealed 63 publications with a total of 4,295 patients with giant cell bone tumors. Of these, 247 (5.8%; 95% confidence interval (95%CI) 5.1-6.5%) patients had lung metastases. Further, the risk factors for lung metastases were the following: recurrence (p < 0.0001), lung metastasis time (p < 0.0001), Campanacci grade II (p = 0.028) and grade III (p = 0.006), localization in the lower limbs (p = 0.0007), curettage (p = 0.0005), and local irradiation of the primary tumor (p = 0.008). All studies showed a high-risk bias due to the absence of blinding of the participants, personnel, and outcome assessment. Special attention should be paid to tumor recurrence in the long follow-up time, since more advanced giant cell bone tumors, particularly in lower extremities, tend to reoccur and metastasize to the lung. Surgical treatment and local irradiation should be performed thoughtfully, with extended follow-up periods.

[H3F3A mutated multicentric giant cell tumor of bone : A very rare primary bone disease]

This article presents the case of a metachronic multicentric giant cell tumor of bone (GCTB). The patient obtained his first diagnosis of GCTB in the left humerus at the age of 47 years. Furthermore, he suffered from a GCTB in the head of his 4th left metacarpal bone and from a recurrence of the latter. All tumors carried the characteristic H3F3A mutation, which was proven by Sanger sequencing and a mutation specific antibody. The case is the first description of a multicentric H3F3A mutated GCTB.

Prognosis of metastatic giant cell tumor of bone in the pre-denosumab era. A systematic review and a meta-analysis

Background

Data on long-term prognosis of metastatic GCT (mGCT) is scant. The frequency of spontaneous regressions (SRs) is unknown. We aimed to estimate the prognosis of mGCT.

Methods

We searched electronic scientific literature databases and generic Internet from January 1980 to August 2017. After identifying eligible studies we performed descriptive analyses and meta-analyses to estimate overall survival (OS), disease specific survival (DSS) and frequency of SRs in the years before the widespread use of denosumab. We performed pre-specified subgroup analyses of studies published before and after 2000 and of those with more and less than 10 years of follow-up.

Results

After retrieving and combining data from 26 relevant retrospective case-series totaling 242 patients with a median follow-up of 6.9 years, the estimated pooled OS was 86.9% (95% CI 78.0-94.2). Pooled DSS was 88.0% (95% CI 79.7-94.7). SRs were observed in 4.5% of patients. In the subgroup of studies published after 2000 mGCT was the only cause of death of affected subjects. In case-series with a follow-up longer than 10 years pooled DSS was 69.7% (95% CI 25.5-99.8).

Conclusions

To our knowledge this is the first study to derive estimated pooled OS and DSS of mGCT based on a large dataset. SRs were not exceptional phenomena. In a long run the disease could impact in a significant way on the life expectancy of affected subjects.

Selective Arterial Embolization for the Treatment of Sacral and Pelvic Giant Cell Tumor: A Systematic Review

Giant cell tumor of the bone (GCTB) is a locally aggressive tumor with a certain distant metastatic rate. For sacral GCT (SGCT) and pelvic GCT (PGCT), surgery has its limitations, especially for unresectable or recurrent tumors. Selective arterial embolization (SAE) is reported to be an option for treatment in several cases, but there are few systematic reviews on the effects of SAE on SGCT and/or PGCT. Medline and Embase databases were searched for eligible English articles. Inclusion and exclusion criteria were conducted before searching. All the clinical factors were measured by SPSS software, with P-values ≤0.05 considered statistically significant. A total of 9 articles were retrieved, including 44 patients receiving SAE ranging from 1 to 10 times. During the mean follow-up period of 85.8 months, the radiographic response rate was 81.8%, with a local control and overall survival rate of 75% and 81.8%, respectively. No bowel, bladder, or sexual dysfunction was observed. Three patients developed distant metastases and finally died. Patients with primary tumors tended to have better prognosis than those with recurrence (P = 0.039). The favorable outcomes of SAE suggest that it may be an alternative treatment for SGCT and PGCT patients for whom surgery is not appropriate.

Development and validation of a prognostic index to predict pulmonary metastasis of giant cell tumor of bone

Purpose

Giant cell tumor of bone (GCTB) is an intermittent tumor with a low probability of pulmonary metastasis. Our aim was to investigate the risk factors and establish a nomogram predictive model for GCTB pulmonary metastasis.

Methods

We retrospectively evaluated GCTB patients at our center from 1991 to 2014. The cohort was randomized into training and validation sets. Univariate and multivariate analyses were used to evaluate the risk factors of pulmonary metastasis. A nomogram was established. Internal validation was achieved based on ROC curve and C-index values in the validation set. Decision curve analysis was performed to assess the clinical performance of the nomogram.

Results

417 patients were studied, including benign and malignant GCTBs. The average follow up was 79 months. Pulmonary metastases were observed in 27 cases. Four independent risk factors were identified: malignancy, tumor bearing time, times of recurrence and tumor size. A nomogram was developed to predict pulmonary metastasis with C-index values of 0.857 and 0.785 in the training and validation groups. In the decision curve analysis, patients could benefit from the nomogram, which differentiates patients at high risk for pulmonary metastasis and avoids unnecessary examination. According to the nomogram, patients with final risks of more than 0.06 should be scheduled for further chest scans.

Conclusion

Malignancy, tumor bearing time, times of recurrence and tumor size were independent risk factors for pulmonary metastasis in GCTB patients. The nomogram can accurately predict the risk of pulmonary metastasis and help doctors to make clinical decisions for further chest examinations.

Detection of H3F3A p.G35W and p.G35R in giant cell tumor of bone by Allele Specific Locked Nucleic Acid quantitative PCR (ASLNAqPCR)

Giant Cell Tumor (GCT) represents about 20% of benign bone tumors, is locally aggressive although malignant transformation is extremely rare, <1% of cases but 2-3% give pulmonary metastasis. Age at onset is between 20 and 40 years with a slight predominance for the female gender. GCT is characterized by specific mutations in H3F3A gene encoding the protein histone 3.3. The study of these mutations is important for the differential diagnosis with giant cell rich sarcomas, chondroblastoma and aneurysmal bone cyst. To identify the most frequent H3F3A mutations we developed a novel allele specific Real Time Polymerase Chain Reaction method, based on Allele Specific Locked Nucleic Acid (ASLNAqPCR) that is here described. Molecular analyses were performed on 20 GCT and 2 osteosarcoma arising on a previous GCT. All cases were verified by Sanger sequencing. We demonstrated that ASLNAqPCR is a quick, sensitive and reliable method to identify mutations of the H3F3A gene, in giant cell tumor of bone, to support diagnosis in morphologically ambiguous cases.

Diagnosing giant cell tumor of the bone using positron emission tomography/computed tomography: A retrospective study of 20 patients from a single center

The aim of the present study was to evaluate the sensitivity of positron emission tomography/computed tomography (PET/CT) in the diagnosis of giant cell tumor of the bone (GCTB) using the maximum standard uptake value (SUVmax), which indicates the metabolic rate of tissue. Patients diagnosed with pathologically confirmed GCTB between January 2006 and July 2015 were included in the study. Data from PET/CT scans and pathological and clinical reports for all patients were retrospectively reviewed. The SUVmax value from the PET/CT scan of each patient was retrieved and analyzed. A total of 20 patients [12 male and 8 female; age range, 12–45 years; mean age ± standard deviation (SD), 33.5±15.7] with complete PET/CT data and a pathologically and clinically confirmed diagnosis were examined. The SUVmax of GCTB was between 1.8 and 18.6, with a mean ± SD of 9.2±3.8. Although GCTB is not considered to be a malignant lesion, PET/CT scans of the tumors reveal high-grade malignant osseous sarcomas. It is, therefore, important not to mistake such lesions for osteosarcomas or metastatic malignancies of the bone.

H3F3A mutation in giant cell tumour of the bone is detected by immunohistochemistry using a monoclonal antibody against the G34W mutated site of the histone H3.3 variant

AIMS

Giant cell tumour of the bone (GCTB) is a neoplasm predominantly of long bones characterized by the H3F3A mutation G34W. Conventional diagnosis is challenged by the tumour's giant cell-rich morphology, which overlaps with other giant cell-containing lesions of the bone. Recently, a monoclonal antibody specific for the H3F3A mutation has been generated. Our aim was to test this antibody on a cohort of giant cell-containing lesions.

METHODS AND RESULTS

We used the antibody for analysis of 22 H3F3A-mutated GCTB, including two patients with recurrences; for comparison we analysed a cohort of 36 H3F3A wild-type giant cell-rich lesions of the bone and soft tissue, containing one brown tumour, six aneurysmal bone cysts (ABC), six chondroblastomas, five non-ossifying-fibromas, two fibrous dysplasias, nine tenosynovial giant cell tumours, one giant cell-rich sarcoma and six osteosarcomas. Furthermore, among the 22 mutated cases, we included one GCTB with two recurrences and lung metastases; the patient was treated with the anti-receptor activator of nuclear factor κB (RANK) ligand denosumab. We show that all 22 H3F3A-mutated GCTB display strong nuclear H3.3 G34W staining in the neoplastic component, while the osteoclastic giant cells are negative. 36 H3F3A wild-type lesions are negative. The GCTB treated with denosumab revealed a reduction in the H3.3 G34W-positive tumour cells and a decrease in osteoclastic giant cells accompanied by matrix and osteoid formation.

CONCLUSIONS

We conclude that positive H3.3 G34W staining is a specific and sensitive method for detection of H3F3A-mutated GCTB. Denosumab treatment leads to a pathomorphosis of the lesion characterized by matrix and osteoid producing H3.3 G34W-negative stromal cells.

H3F3 mutation status of giant cell tumors of the bone, chondroblastomas and their mimics: a combined high resolution melting and pyrosequencing approach

Behjati et al recently described recurrent mutations of H3F3 genes in giant cell tumors of the bone and chondroblastomas. Both these entities belong to the spectrum of giant cell-rich bone lesions, often presenting a diagnostic challenge for the pathologist. Our aim was to investigate the value of searching for H3F3 mutations in the diagnosis of giant cell tumors of the bone and giant cell-rich chondroblastomas. Two hundred eighty-one bone lesion samples, including 170 giant cell tumors of the bone, 26 chondroblastomas and 85 other giant cell-rich and/or epiphyseal tumors, were analyzed. Mutation status was determined using first high resolution melting screening and then mutation profiling pyrosequencing. Mutational status was compared with clinical data and, for giant cell tumors of the bone, with p63 immunostaining status. As histone methylation changes have been reported in association with H3F3 mutations, the methylation status of lysine 37 was investigated. H3F3A and H3F3B were found in 85% of giant cell tumors of the bone and 88% of chondroblastomas. In addition to the major G35W mutation, we found two rare H3F3A mutations: one G35R and one G35V. Among the other tumors studied, we only found H3F3A gene mutations in two cases of 'dedifferentiated chondrosarcoma mimicking giant cell tumor of the bone'. A H3F3B mutation was also observed in one case of dedifferentiated chondroblastoma. P63 expression in giant cell tumors of the bone seems to be associated with H3F3 gene mutations (P=0.004). H3F3 mutations did not correlate with clinical data, outcome or methylation changes in Lysin 37. In conclusion, H3F3 mutations are sensitive and specific markers of giant cell tumors of the bone and chondroblastomas. High resolution melting and pyrosequencing procedures are high-performance tools in this context. Determination of H3F3 mutation will allow reclassification of some entities belonging to the spectrum of giant cell-rich lesions.

Expression of Matrix Metalloproteinase-9 and CD34 in Giant Cell Tumor of Bone

OBJECTIVE

Giant cell tumor of bone (GCTB) invades extensively and metastasizes, however, the pathological grade and imaging findings are not accurate predictors of its prognosis. Thus, the aim of this study was to explore the relationships between expression of cluster of differentiation (CD)34 and matrix metalloproteinase-9 (MMP-9) and the biological behavior of GCTB with the hope of identifying predictors of prognosis.

METHODS

Sixty-eight patients with GCTBs attending our institution from September 2008 to August 2013 were enrolled in this prospective study and grouped according to tumor location. Relevant patient characteristics were assessed. Additionally, the expression of CD34 and MMP-9 in these patients was assayed by an immunohistochemistry staining procedure and the relationships between CD34/MMP-9 and microvessel density (MVD) analyzed by Spearman correlation analysis.

RESULTS

It was found that CD34 factor localizes in the cytoplasm of the endothelial cells of small blood vessels in the tumor stroma and is strongly expressed in GCTBs. In addition, radiological grading showed that there was significantly more CD34 antibody-labeled MVD in invasive than in non-invasive tumors (P < 0.05) and significantly more CD34 antibody-labeled MVD in patients who developed recurrences than in those who did not (P < 0.05). Expression of MMP-9 was localized in the cytoplasm of tumor cells and the rate of MMP-9 positivity in GCTBs was significantly higher in active and invasive tumors than in non-invasive tumors (P < 0.01). Moreover, there were significantly more MVDs in MMP-9-positive than in MMP-9 negative tumors (P < 0.01). CD34 and MMP-9 are positively correlated with MVD values in GCTBs and closely correlated with their grade of malignancy.

CONCLUSION

Expression of CD34 and MMP-9 accurately predicts clinical behavior detection and prognosis of GCTBs.

An Unusual and Complicated Course of a Giant Cell Tumor of the Capitate Bone

A 51-year-old female patient presented with a carpal giant cell tumor (GCT) of the right capitate bone. The lesion was initially misdiagnosed as having an osteomyelitis. First, the diagnosis of a benign GCT was confirmed by histological examination. Second, an intralesional curettage and packing of the cavity with cancellous iliac crest bone grafts combined with a fusion of the third carpometacarpal (CMC III) joint were carried out. Third, due to a secondary midcarpal osteoarthritis and a secondary scaphoid nonunion, the CMC III joint fusion plate was removed and the midcarpal joint completely excised. Fourth, in the absence of recurrence of GCT, a four-corner fusion (4CF) with a corticocancellous iliac crest bone graft and complete excision of the scaphoid bone had to be performed. Fifth, a total wrist arthroplasty (TWA) was performed due to hardware failure of 4CF with migration of a headless compression screw into radiocarpal joint which led to erosion of articular surface of the distal radius. At the 3-year follow-up that includes a 1-year follow-up after TWA, there was no recurrence of GCT, and the TWA was not failed. The patient reported that she would have the motion-preserving TWA again.

A solitary pleural metastasis of benign giant cell tumor of bone

Giant cell tumor of bone (GCTB) usually appears as a benign tumor. We describe an extremely rare case of a metastatic pleural tumor arising from a benign GCTB. The patient had undergone radial resection of a GCTB in his left wrist. After 6 years, he was sent to us for diagnosis of a large mass detected upon routine radiographic screening. We resected the tumor, which was found to be a solitary pleural metastasis of GCTB and had evidently spread arterially. To our knowledge, this is the first report of its kind.

Surgery methods and soft tissue extension are the potential risk factors of local recurrence in giant cell tumor of bone

Background

Various treatments of giant cell tumor of bone (GCTB) included in curettages and resections and with adjuvant are exerted, but the best treatment is controversial. The aim of the study was the identification of individual risk factors after various treatments in GCTB.

Methods

A total of 179 patients treated for GCTB between 1998 and 2010 were concluded in the retrospective study. All patients were treated with intralesional curettage, extensive curettage, or wide resection. Mean follow-up was 60.2 ± 18.7 months (36~112 months). Age, gender, tumor location, Campanacci grade, soft tissue extension, pathological features, and surgical methods were performed to univariate Kaplan-Meier survival analysis and multivariate Cox regression analysis.

Results

The local recurrence rates of intralesional curettage (41.9 %) and extensive curettage (19.0 %) were significantly higher than that of wide resection (7.7 %). The higher risk of local recurrence was found for soft tissue extension (hazard = 7.921, 95 % CI 1.107~56.671), compared with no statistical significances between gender, location, Campanacci grade, pathologic fracture, and local recurrences, which were shown by Kaplan-Meier analysis. However, recurrence-free survival (RFS) of patients younger than 30 was significantly lower than that of patients older than 30. The RFS of pathologic fracture patients with soft tissue extension was significantly lower than that of pathologic fracture patients without soft tissue extension. Multivariate Cox regression analysis indicated that the independent variable that contributed to recurrence-free survival was soft tissue extension and surgical methods. The RFS of extensive curettage had no statistically significant difference with wide resection and was significantly higher than that of intralesional curettage. Use of high-speed burring and bone cement significantly decreased the local recurrence rate.

Conclusions

Age (below 30 years), gender, tumor location, Campanacci grade, and pathologic fracture have no statistically significant influence on local recurrences. Soft tissue extension and intralesional curettage of surgical methods increased the RFS. The results of the present study suggested that compared with curettage and wide section, treatment of GCTB by extensive curettage could provide the favorable local control and functional recovery.

Electronic supplementary material

The online version of this article (doi:10.1186/s12957-016-0871-z) contains supplementary material, which is available to authorized users.