Population-based study of giant cell tumor of bone in Sweden (1983-2011)

Diaphyseal giant cell tumour of mid-shaft tibia

SummaryGiant cell tumours of bone are benign and locally aggressive tumours that usually occur in young adults and at the epiphysial locations after physeal closure. Occurrence outside of epiphysial locations and appearance in geriatric patients is rare. We report a case of a woman in her late 60s with a giant cell tumour of the mid-shaft of the right tibia. Extended curettage and biological reconstruction were performed with autologous double-barrel fibular struts and tri-cortical iliac crest bone grafting. At the 28-month follow-up examination, we noted full bony union at both ends with successful consolidation of the fibular struts, and importantly, no evidence of recurrence or other complications was observed.

Evaluating Extended Curettage and Adjuvant Therapy Against Wide Resection and Reconstruction in the Management of Distal Radius Giant Cell Tumors: A Systematic Review and Meta-analysis

BACKGROUND

The management of distal radius giant cell tumors (GCTs) remains challenging, and the optimal approach is still a matter of debate. This systematic review and meta-analysis aimed to compare the outcomes of extended curettage and wide resection, the mainstays of treatment.

METHODS

Medline (via PubMed), Cochrane Library, Web of Science, Google Scholar, ClinicalTrials.gov, and Embase databases were searched for comparative studies that assessed extended curettage with adjuvant therapy and wide resection with reconstruction in patients with GCTs of the distal radius up to April 2023. Data were collected and analyzed on rates of local recurrence, metastasis, overall complications, and functional outcomes. The Newcastle-Ottawa scale was used to appraise the risk of bias within each study.

RESULTS

Fifteen studies (n = 373 patients) were included and analyzed. Patients who underwent curettage were more likely to develop recurrence (risk ratio [RR] = 3.02 [95% confidence interval; CI, 1.87-4.89], P < .01), showed fewer complications (RR = 0.32 [95% CI, 0.21-0.49], P < .01), and showed greater improvement in Visual Analog Scale and lower Disabilities of the Arm, Shoulder, and Hand scores (P < .00001) than those who underwent wide resection. No significant difference was found regarding metastasis (RR = 1.03 [95% CI, 0.38-2.78], P = .95).

CONCLUSIONS

Regarding the surgical approach to GCT of the distal radius, curettage with adjuvant therapy was associated with a higher likelihood of recurrence compared with wide resection with reconstruction. Nevertheless, the curettage approach resulted in significantly lower rates of operative complications, decreased pain scores, and better functional outcomes in comparison to the resection group.

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.

RANKL, OPG, and RUNX2 expression and epigenetic modifications in giant cell tumour of bone in 32 patients

Aims

The present study investigated receptor activator of nuclear factor kappa-Β ligand (RANKL), osteoprotegerin (OPG), and Runt-related transcription factor 2 (RUNX2) gene expressions in giant cell tumour of bone (GCTB) patients in relationship with tumour recurrence. We also aimed to investigate the influence of CpG methylation on the transcriptional levels of RANKL and OPG.

Methods

A total of 32 GCTB tissue samples were analyzed, and the expression of RANKL, OPG, and RUNX2 was evaluated by quantitative polymerase chain reaction (qPCR). The methylation status of RANKL and OPG was also evaluated by quantitative methylation-specific polymerase chain reaction (qMSP).

Results

We found that RANKL and RUNX2 gene expression was upregulated more in recurrent than in non-recurrent GCTB tissues, while OPG gene expression was downregulated more in recurrent than in non-recurrent GCTB tissues. Additionally, we proved that changes in DNA methylation contribute to upregulating the expression of RANKL and downregulating the expression of OPG, which are critical for bone homeostasis and GCTB development.

Conclusion

Our results suggest that the overexpression of RANKL/RUNX2 and the lower expression of OPG are associated with recurrence in GCTB patients.

Conversion in a Resectable Tumor after Denosumab Neoadjuvant in a Large Dorsal Giant Cells Tumor: A Case Report and a Literature Review

Giant cell tumors of bone are a rare entity, usually occurring in young patients and characteristically arising in the long bones. The spinal location is rare and usually presents with pain and/or neurological symptoms. The treatment of choice is surgery. Treatment with Denosumab, a bisphosphonate inhibitor of RANK-L, which is highly expressed in these tumors, has shown extensive activity in unresectable patients or those undergoing incomplete surgery. Preoperative treatment with this drug is gaining increasing interest, as its high potency in tumor reduction in this subtype of neoplasm has allowed resectability in selected patients. We present the case of a young patient with a large spinal tumor who, after neoadjuvant Denosumab, underwent complete en bloc surgery with clean margins and a great pathological response.

Giant Cell Tumors With HMGA2::NCOR2 Fusion : Clinicopathologic, Molecular, and Epigenetic Study of a Distinct Entity

Giant cell tumors (GCTs) with high mobility group AT-Hook 2 ( HMGA2 )::nuclear receptor corepressor 2 ( NCOR2 ) fusion are rare mesenchymal tumors of controversial nosology, which have been anecdotally reported to respond to CSFR1 inhibitors. Here, we performed a comprehensive study of 6 GCTs with HMGA2::NCOR2 fusion and explored their relationship with other giant cell-rich neoplasms. Tumors occurred in 4 females and 2 males ranging in age from 17 to 32 years old (median 24). Three lesions originated in subcutaneous soft tissue and 3 in bone. Tumor size ranged from 20 to 33 mm (median 27 mm). The lesions had a nodular/multinodular architecture and were composed of sheets of mononuclear "histiocytoid" cells with uniform nuclei intermingled with multinucleated giant cells. Mitotic activity was low and nuclear atypia and metaplastic bone were absent. Variable findings included necrosis, cystic degeneration, lymphocytic infiltrate (sometimes forming nodules), and xanthogranulomatous inflammation. On immunohistochemistry, all cases focally expressed pan-keratin and were negative with SATB2 and H3.3G34W. Whole RNA-sequencing was performed in all cases of GCT with HMGA2::NCOR2 fusion and a subset of giant cell-rich tumors (tenosynovial-GCT, n = 19 and "wild-type" GCT of soft tissue, n = 9). Hierarchical clustering of RNA-sequencing data showed that GCT with HMGA2::NCOR2 fusion formed a single cluster, independent of the other 2 entities. Methylome profiling showed similar results, but the distinction from "wild-type" GCT of soft tissue was less flagrant. Gene expression analysis showed similar levels of expression of the CSF1/CSFR1 axis between GCT with HMGA2::NCOR2 fusion and tenosynovial-GCT, supporting their potential sensitivity to CSFR1 inhibitors. Clinical follow-up was available for 5 patients (range: 10 to 64 mo; median 32 mo). Three patients (60%) experienced local recurrences, whereas none had distant metastases or died of disease. Overall, our study confirms and expands previous knowledge on GCT with HMGA2::NCOR2 fusion and supports its inclusion as an independent entity.

Giant cell tumor of bone with H3F3B mutation: A case report

RATIONALE

Giant cell tumor of bone is a locally aggressive and rarely metastasizing neoplasm that typically affects the ends of long bones or the axial skeleton of young to middle-aged adults. As many as 69% to 100% of giant cell tumors harbor H3F3A gene mutations, while H3F3B gene mutations have rarely been reported.

PATIENT CONCERNS

A 53-year-old male patient who underwent right distal femoral tumor resection.

DIAGNOSES

Preoperative CT plain scan indicated giant cell tumor of bone with pathological fracture. Laboratory findings were as follows: serum calcium was 2.23 mmol/L (reference range: 2.1-2.55 mmol/L) and serum phosphorus was 1.35 mmol/L (reference range: 0.81-1.45 mmol/L).

INTERVENTIONS

The histological morphology showed the typical features of a conventional GCT. The immunoprecipitation analysis results were as follows: H3.3G34W(-), H3.3G34R(-), H3.3G34V(-), and H3K36M(-). Sanger sequencing showed that the H3F3A and H3F3B gene mutations were wild type. The high-throughput gene sequencing results revealed the H3F3B gene mutations H3.3p.Gly35Trp and H3.3p.Val36Leu.

OUTCOMES

The patient was stable with no recurrence in 12 months follow-up.

LESSONS

Giant cell tumor of bone with H3F3B gene mutations is extremely rare. In the pathological diagnosis of bone tumors, we need to analyze clinical presentation, imaging features, histology, immunophenotype, and cytogenetic/molecular alterations, in order to get a correct diagnosis.

A Retrospective Observational Study on Disease Characteristics and Treatment Patterns of Giant Cell Tumor of the Bone in China

Aims

Giant cell tumor of the bone (GCTB) is associated with considerable morbidity. As GCTB epidemiological data for China are limited, this study is aimed at describing the disease characteristics of GCTB in China and establishing the historical context for its treatment before recent advances in treatment options.

Methods

The disease characteristics, treatment patterns, and local GCTB recurrence rate after primary surgery for GCTB were evaluated in this single-center, retrospective, noninterventional, observational study of patients treated for GCTB at Ji Shui Tan Hospital, Beijing, from 2009 to 2016 based on medical chart review. Patients with unmet need were defined as those whose surgical treatment was difficult or who had to undergo high-morbidity surgery.

Results

Among the 668 patients with a primary GCTB diagnosis, 578 (86.5%) of target lesions were in the extremities, and 89 (13.3%) were in the pelvic or axial bone. Of these, 173 (25.9%) were characterized as having an unmet need. Almost all GCTB patients received surgical treatment at both primary diagnosis (666/668 (99.7%)) and last disease recurrence (196/200 (98.0%)). Additionally, about one-third of patients received nonsurgical treatment at primary diagnosis (205/668 (30.7%)) and disease recurrence (67/200 (33.5%)), with neoadjuvant therapy being the most common treatment. The rate of high-morbidity surgery increased for recurrent disease (65/200 (32.5%)) compared with primary diagnosis (111/668 (16.6%)). The 2-year cumulative incidence of postoperative disease recurrence was 29.2%, in line with rates observed in prior studies.

Conclusion

As many patients with primary and recurrent disease received high-morbidity surgery, more effective treatments are needed.

[Giant-cell tumor of bone in 2022]

Giant cell tumors of bone (GCTs) are rare mesenchymal tumors classified as intermediate in the WHO 2020 classification, i.e. neither completely benign nor definitely malignant, due to recurrence (frequent) and pulmonary metastases (rare). They involve the end of long bones as well as the axial bones of mature skeletons. They are made of mononuclear stromal tumor cells of (pre-) osteoblastic phenotype, mononuclear cells of the monocyte-macrophage lineage and osteoclast-like multinuclear giant cells responsible for tumor osteolysis. In 95% of cases, the stromal cells have a specific mutation in the H3F3A gene which encodes histone H3.3. The mutated H3.3 G34W protein (90% of cases) can be easily detected by immunohistochemistry, even on small samples. Many tumors or bone pseudotumors contain osteoclast-like giant cells, cells of the bone microenvironment, and should not be confused with GCT: mainly brown tumor of hyperparathyroidism, aneurysmal bone cyst, chondroblastoma, non-ossifying fibroma and central giant cell granuloma.

[Giant cell-containing tumors of bone and differential diagnoses]

Osteoclastic giant cells represent a common cellular component of lesions arising in bone. Highlighting this morphological finding, the current WHO classification of bone tumors defines a diagnostic group comprising aneurysmal bone cyst, giant cell tumor of bone and non-ossifying fibroma, which may display morphologic similarities while being distinct with regard to molecular and biological features. Starting with these tumors - putting a focus on lesions arising in bone - this article gives a survey of other (chondrogenic and osteogenic) tumors that frequently contain osteoclastic giant cells, which may, particularly in small biopsies, enter differential diagnosis. Overlapping features with selected giant cell-containing soft tissue tumors, which may be of differential diagnostic relevance in daily routine, are discussed.

SELNET clinical practice guidelines for bone sarcoma

Bone sarcoma are infrequent diseases, representing < 0.2% of all adult neoplasms. A multidisciplinary management within reference centers for sarcoma, with discussion of the diagnostic and therapeutic strategies within an expert multidisciplinary tumour board, is essential for these patients, given its heterogeneity and low frequency. This approach leads to an improvement in patient's outcome, as demonstrated in several studies. The Sarcoma European Latin-American Network (SELNET), aims to improve clinical outcome in sarcoma care, with a special focus in Latin-American countries. These Clinical Practice Guidelines (CPG) have been developed and agreed by a multidisciplinary expert group (including medical and radiation oncologist, surgical oncologist, orthopaedic surgeons, radiologist, pathologist, molecular biologist and representatives of patients advocacy groups) of the SELNET consortium, and are conceived to provide the standard approach to diagnosis, treatment and follow-up of bone sarcoma patients in the Latin-American context.

Current management of giant-cell tumor of bone in the denosumab era

Giant-cell tumor of bone is a rare, locally aggressive and rarely metastasizing primary bone tumor. The mainstay of treatment remains controversial and is decided by the balance between adequate surgical margin and sufficient adjacent joint function. Although curettage with a high-speed burr and local adjuvants can maintain normal joint function, many reports have revealed a high local recurrence rate. Conversely, en bloc resection and reconstruction with prostheses for highly aggressive lesions have reportedly lower local recurrence rates and poorer functional outcomes. Denosumab-a full human monoclonal antibody that inhibits receptor activator of nuclear factor-kappa β ligand-was approved by the Food and Drug Authority in 2013 for use in surgically unresectable or when resection is likely to result in severe morbidity for skeletally mature adolescents and adults with giant-cell tumor of bone. However, subsequent studies have suggested that the local recurrence rate would be increased by preoperative use of denosumab. In systematic reviews of the local recurrence rate after preoperative use of denosumab, conclusions vary due to the small sample sizes of the studies reviewed. Therefore, controversy regarding the treatment of giant-cell tumor of bone is ongoing. Here, this review elucidates the management of giant-cell tumor of bone, especially with the local adjuvant and neoadjuvant use of denosumab, and presents the current, evidence-based treatment for giant-cell tumor of bone.

OUP accepted manuscript

Background

Methods

Results

Conclusions

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.

Role of denosumab before resection and reconstruction in giant cell tumors of bone: a single-centered retrospective cohort study

BACKGROUND

Denosumab has been approved by Food and Drug Authority in 2013 for use in surgically unresectable Giant cell tumor (GCT) to achieve resectable tumor margins. The aim of this study is to investigate the functional outcome and surgical convenience with the use of neoadjuvant denosumab before resection and reconstruction in Campanacci grade III GCT.

METHODS

We retrospectively reviewed 70 cases of Campanacci grade III GCT receiving resection and reconstruction between January 2014 and December 2019. They were stratified into two groups: one group of 29 patients received once-weekly denosumab 120 mg for 4-weeks before resection and reconstruction, while the other group of 41 patients did not receive denosumab before resection and reconstruction. Quality of life by musculoskeletal tumor society score where 0-7 means poor, 8-14 means fair, 15-22 means good; above 22 means excellent, incidence of tumor recurrence, intraoperative duration in minutes and postoperative positive margins were assessed for each cohort after 12 months follow-up.

RESULTS

There was no significant difference in musculoskeletal tumor society score (25.75 vs. 27.41; P  = 0.178), incidence of recurrence (3.45% vs. 4.88%; P  < 0.001), and postoperative positive margins (10.34% vs. 4.88%; P  = 0.38) for both groups. However, the intraoperative duration (133.38 vs. 194.49; P  < 0.001) was significantly higher in the non-denosumab group compared with denosumab group.

CONCLUSIONS

Neoadjuvant denosumab is equally effective considering postoperative functional outcomes and surgical convenience except intraoperative duration where it is highly helpful in saving the operating time duration. Easier identification, resection and lesser reconstruction are the key surgical convenience offered by neoadjuvant denosumab.

The 2020 WHO Classification of Tumors of Bone: An Updated Review

Bone tumors are a rare and heterogeneous group of neoplasms that occur in the bone. The diversity and considerable morphologic overlap of bone tumors with other mesenchymal and nonmesenchymal bone lesions can complicate diagnosis. Accurate histologic diagnosis is crucial for appropriate management and prognostication. Since the publication of the fourth edition of the World Health Organization (WHO) classification of tumors of soft tissue and bone in 2013, significant advances have been made in our understanding of bone tumor molecular biology, classification, prognostication, and treatment. Detection of tumor-specific molecular alterations can facilitate the accurate diagnosis of histologically challenging cases. The fifth edition of the 2020 WHO classification of tumors of soft tissue and bone tumors provides an updated classification scheme and essential diagnostic criteria for bone tumors. Herein, we summarize these updates, focusing on major changes in each category of bone tumor, the newly described tumor entities and subtypes of existing tumor types, and newly described molecular and genetic data.

Prognostic Factors for Survival in Patients with Malignant Giant Cell Tumor of Bone: A Risk Nomogram Analysis Based on the Population

Background

Malignant giant cell tumor of bone (MGCTB) is a rare histological type of malignant tumor that has a high tendency for local relapse and distant metastasis and ultimately leads to a poor prognosis. The purpose of this study was to describe the epidemiological features, identify the prognostic factors, and construct nomograms for patients with MGCTB.

Material/Methods

Patients with MGCTB that was histologically diagnosed between 1973 and 2014 were selected from the Surveillance, Epidemiology, and End Results (SEER) database as a training set. Survival analysis, Lasso regression, and random forests were used to identify the prognostic variables and establish the nomograms for patients with MGCTB, while an external cohort of 37 patients from our own institution and an external cohort of 163 patients from the SEER database in 2016 were used to validate the generalization performance of the nomograms.

Results

In total, univariate and multivariable analysis indicated that age, International Classification of Diseases for Oncology, historical stage, primary site, surgery information, radiotherapy, and chemotherapy were independent prognostic variables for overall survival or cause-specific survival. Nomograms based on the multivariable models were built to predict survival, and we achieved a higher C-index in subsequent multidimensional validation.

Conclusions

Age, historical stage, and chemotherapy were independent prognostic variables for overall survival and cause-specific survival of MGCTB patients, and radiotherapy and primary site were independent prognostic variables for overall survival. Nomograms based on significant clinicopathological features and clinical experience can be effective in predicting the probability of survival for MGCTB patients.

H3F3A G34 mutation DNA sequencing and G34W immunohistochemistry analysis in 366 cases of giant cell tumors of bone and other bone tumors

H3F3A mutations and the expression of glycine 34 to tryptophan (G34W) mutants in giant cell tumors of bone (GCTBs) and other bone tumors were detected to compare H3F3A mutation types and the expression of G34W-mutant protein in order to provide a theoretical basis for using H3F3A mutations as a diagnostic and differential-diagnostic tool for GCTBs. A total of 366 bone tumor cases were investigated. The cases involved 215 men and 151 women, whose median age was 29 years (3-84). The cases included GCTB (n=180), recurrent GCTB (n=19), GCTB with lung metastasis (n=5), pediatric GCTB (n=15), primary malignant GCTB (n=5), chondroblastoma (CB, n=61), chondrosarcoma grade II (n=15), dedifferentiated chondrosarcoma (n=17), chondromyxoid fibroma (n=9), aneurysmal bone cyst (n=9), nonossifying fibroma (n=9), osteosarcoma (n=16), and undifferentiated sarcoma (n=6). Sanger DNA sequencing analysis was used to detect H3F3A mutations. Immunohistochemistry was used to assess the expression of the G34W-mutated protein in these bone tumors. DNA sequencing results revealed H3F3A mutations in 95.00% of GCTBs (171/180), including glycine 34 to tryptophan (G34W, 163/180, 90.56%), glycine 34 to leucine (G34L, 3/180, 1.67%), glycine 34 to valine (G34V, 3/180, 1.67%), and glycine 34 to arginine (G34R, 2/180, 1.11%). Recurrent GCTBs mostly had the H3F3A G34W mutation (18/19, 94.74%), and GCTBs with lung metastasis all had the H3F3A G34W mutation (5/5, 100%). Pediatric GCTBs had a mutation rate of 93.33% (14/15), including one case with G34L. Four cases of primary malignant GCTB showed the H3F3A G34W mutation (4/5, 80.00%), and the classical GCTB component and malignant component showed consistent mutation types. Immunohistochemistry showed that GCTBs harboring G34W also expressed the mutant protein in tumor cell nuclei. Furthermore, one case of GCTB and one case of recurrent GCTB showed positive G34W immunostaining results despite being negative for the genetic mutation. Other bone tumors all showed wild-type expression in both DNA sequencing and immunohistochemistry. Our large-sample DNA sequencing analysis detected four different forms of mutations in GCTBs, including three rare mutation forms. The most common mutation of H3F3A was G34W, which was in accordance with the expression of G34W in GCTBs detected by immunohistochemistry. Although DNA sequencing analysis detected rare mutation types of H3F3A, false-negative results were also present due to the small number of cells in the samples. Detection of the most common (G34W) mutant protein by immunohistochemistry was more convenient. Given the high prevalence of these driver mutations, the detection of H3F3A mutant proteins can assist in the diagnosis of GCTB and its differential diagnosis from other bone tumors.

Successful Treatment with Denosumab of a Giant Cell Tumor of Bone in the Iliac Bone of an 84-Year-Old Man

We report a case of GCTB in an 84-year-old Japanese man who had a tumor in his left iliac bone and was treated safely with denosumab. The patient noticed a painful mass, with gradual enlargement, in his left low back next to the iliac region. Magnetic resonance imaging revealed that the tumor measured 94 × 66 × 90 mm and was located in the left iliac bone. Histologically, the tumor was composed of proliferative oval-shaped mononuclear cells, admixed with large number of osteoclast-like giant cells. Immunohistochemically, a strong positivity for histone 3.3 G34W mutant protein was observed in the nuclei of the mononuclear cells, confirming the diagnosis of GCTB. Because it was considered as unresectable tumor, the patient was treated with denosumab without any side effects.

Significance of EGFR/HER2 Expression and PIK3CA Mutations in Giant Cell Tumour of Bone Development

Giant Cell Tumour of Bone (GCTB) is a rare bone tumour. Locally aggressive and recurrent, it might evolve into pulmonary metastases. Our present work is aimed at investigating the involvement of the epidermal growth factor receptor (ErbB) family and its downstream effectors in the development and recurrence of GCTB. For this purpose, we used a cohort of 32 GCTB patients and we evaluated the clinicohistological features and the expression of RANKL, EGFR, and HER2. The mutation status of KRAS, PI3KCA, and PTEN gene as potential oncogene involved in GCTB was also evaluated. We found a significant correlation between advanced histological stages, overexpression of EGFR/HER2, and tumour recurrence. Moreover, two mutations were found in the PIK3CA gene: a missense mutation, 1634A>C, detected for the first time in GCTB patients, without influencing the stability of the protein, and a frameshift mutation, c.1658_1659delGTinsC, causing the loss of the protein kinase domain. Altogether, these results suggest that overexpression of HER2/EGFR, Campanacci, and histological stages could be used as a novel prognostic marker for GCTB recurrence.

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.

Role of cancer stem cells in the development of giant cell tumor of bone

The primary bone tumor is usually observed in adolescence age group which has been shown to be part of nearly 20% of the sarcomas known today. Giant cell tumor of bone (GCTB) can be benign as well as malignant tumor which exhibits localized dynamism and is usually associated with the end point of a long bone. Giant cell tumor (GCT) involves mononuclear stromal cells which proliferate at a high rate, multinucleated giant cells and stromal cells are equally present in this type of tumor. Cancer stem cells (CSCs) have been confirmed to play a potential role in the development of GCT. Cancer stem cell-based microRNAs have been shown to contribute to a greater extent in giant cell tumor of bone. CSCs and microRNAs present in the tumors specifically are a great concern today which need in-depth knowledge as well as advanced techniques to treat the bone cancer effectively. In this review, we attempted to summarize the role played by cancer stem cells involving certain important molecules/factors such as; Mesenchymal Stem Cells (MSCs), miRNAs and signaling mechanism such as; mTOR/PI3K-AKT, towards the formation of giant cell tumor of bone, in order to get an insight regarding various effective strategies and research advancements to obtain adequate knowledge related to CSCs which may help to focus on highly effective treatment procedures for bone tumors.

In situ cell cycle analysis in giant cell tumor of bone reveals patients with elevated risk of reduced progression-free survival

OBJECTIVE

Giant cell tumor of bone (GCTB) is a frequently recurring locally aggressive osteolytic lesion, where pathological osteoclastogenesis and bone destruction are driven by neoplastic stromal cells. Here, we studied if cell cycle fractions within the mononuclear cell compartment of GCTB can predict its progression-free survival (PFS).

METHODS

154 cases (100 primaries and 54 recurrent) from 139 patients of 40 progression events, was studied using tissue microarrays. Ploidy and in situ cell cycle progression related proteins including Ki67 and those linked with replication licensing (mcm2), G1-phase (cyclin D1, Cdk4), and S-G2-M-phase (cyclin A; Cdk2) fractions; cell cycle control (p21^waf1) and repression (geminin), were tested. The Prentice-Williams-Peterson (PWP) gap-time models with the Akaike information criterion (AIC) were used for PFS analysis.

RESULTS

Cluster analysis showed good correlation between functionally related marker positive cell fractions indicating no major cell cycle arrested cell populations in GCTB. Increasing hazard of progression was statistically associated with the elevated post-G1/S-phase cell fractions. Univariate analysis revealed significant negative association of poly-/aneuploidy (p < 0.0001), and elevated cyclin A (p < 0.001), geminin (p = 0.015), mcm2 (p = 0.016), cyclin D1 (p = 0.022) and Ki67 (B56: p = 0.0543; and Mib1: p = 0.0564 -strong trend) positive cell fractions with PFS. The highest-ranked multivariate interaction model (AIC = 269.5) also included ploidy (HR 5.68, 95%CI: 2.62-12.31, p < 0.0001), mcm2 (p = 0.609), cyclin D1 (HR 1.89, 95%CI: 0.88-4.09, p = 0.105) and cyclin A (p < 0.0001). The first and second best prognostic models without interaction (AIC = 271.6) and the sensitivity analysis (AIC = 265.7) further confirmed the prognostic relevance of combining these markers.

CONCLUSION

Ploidy and elevated replication licensing (mcm2), G1-phase (cyclin D1) and post-G1 phase (cyclin A) marker positive cell fractions, indicating enhanced cell cycle progression, can assist in identifying GCTB patients with increased risk for a reduced PFS.

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.

Incidence and demographics of giant cell tumor of bone in The Netherlands: First nationwide Pathology Registry Study

Background and purpose - Giant cell tumors of bone (GCT-B) are rare, locally aggressive tumors characterized by an abundance of giant cells. Incidence studies for GCT-B are rare. This is the first study using a fully automated 100% covering pathology database, the nationwide Dutch Pathology Registry (17 million inhabitants), PALGA, to calculate incidence rates for GCT-B. Patients and methods - From PALGA, all pathology excerpts were retrieved for patients diagnosed with GCT-B, giant cell tumors of tenosynovium, and giant cell tumors of soft tissue between January 1, 2009 and December 31, 2013. The incidence of GCT-B was calculated. Results - In total, 8,156 excerpts of 5,922 patients were retrieved; these included 138 first GCT-B diagnosis. For GCT-B the incidence was 1.7 per million inhabitants per year with a male to female ratio of 1:1.38 and a median age of 35 years (9-77). Most common localization was the femur (35%), followed by the tibia (18%). No differences in localization according to age and sex were found. The incidence rate of local recurrence was 0.40 per million inhabitants per year. Interpretation - This is the first nationwide study reporting the incidence of GCT-B, based on a nationwide pathology database with 100% coverage of pathology departments. Current incidence calculations are based only on doctor-driven registries. We confirmed that GCT-B is a rare disease with an incidence that is slightly higher than previously published. The relatively young median age of patients and the high incidence of recurrence stresses the importance of developing more effective treatments for this disease.

Giant Cell Tumor of Bone in Patients 55 Years and Older: A Study of 34 Patients

OBJECTIVES

Most giant cell tumors of bone (GCTs) occur in patients aged 20 to 40 years. We analyzed features of GCT in patients 55 years or older.

METHODS

GCTs were examined for fibrosis, matrix, cystic change, histiocytes, mitoses, and necrosis. Clinical/radiologic data were collected.

RESULTS

Thirty-four (5%) of 710 GCTs occurred in patients older than 55 years (14/20 male/female; 56-83 years) in long bones (n = 24), vertebrae (n = 6), pelvis (n = 3), and metacarpal (n = 1). Imaging was classic in 26 of 27 cases; one case appeared malignant. Morphologic patterns included fibrosis (n = 29), bone formation (n = 19), cystic change (n = 8), necrosis (n = 8), foamy histiocytes (n = 7), and secondary aneurysmal bone cyst formation (n = 1). Mitoses ranged from 0 to 18 per 10 high-power fields. Six recurred; one patient developed metastasis. Four of five cases harbored H3F3A mutations.

CONCLUSIONS

GCTs in patients 55 years or older share pathologic characteristics with those arising in younger adults. Fibrosis and reactive bone are common, potentially leading to diagnostic confusion in this population. No histologic features correlate with adverse outcome.

Biology of Bone Sarcomas and New Therapeutic Developments

Bone sarcomas are tumours belonging to the family of mesenchymal tumours and constitute a highly heterogeneous tumour group. The three main bone sarcomas are osteosarcoma, Ewing sarcoma and chondrosarcoma each subdivided in diverse histological entities. They are clinically characterised by a relatively high morbidity and mortality, especially in children and adolescents. Although these tumours are histologically, molecularly and genetically heterogeneous, they share a common involvement of the local microenvironment in their pathogenesis. This review gives a brief overview of their specificities and summarises the main therapeutic advances in the field of bone sarcoma.

The distinct clinical features of giant cell tumor of bone in pagetic and non-pagetic patients are associated with genetic, biochemical and histological differences

Giant Cell Tumor of Bone (GCT) is a tumor characterized by neoplastic mesenchymal stromal cells and a high number of osteoclast-like multinucleated giant cells. Rarely, GCT could arise in bones affected by Paget's disease of bone (GCT/PDB). Although it is already known that GCT/PDB and GCT show a different clinical profile regarding the age-onset and skeletal localization, our deep clinical comparison between the two GCT/PDB and GCT cohorts, permitted us to identify additional differences (e.g. focality, ALP serum levels, the 5-year survival rate and the familial recurrence), strongly suggesting a different molecular basis. Accordingly, driver somatic mutations in H3F3A and IDH2 were described in GCT patients, while we recently identified a germline mutation in ZNF687 as the genetic defect of GCT/PDB patients. Here, we detected H3F3A mutations in our GCT cohort, confirming its molecular screening as the elected diagnostic tool, and then we excluded the two-hit in H3F3A and IDH2 as the trigger event for the GCT/PDB development. Importantly, we also identified an alternative biochemical profile with GCT/PDB not exhibiting the up-regulation of the GCT marker FGFR2IIIc. Finally, our histological analysis also showed a different appearance of the two forms of the tumor, with GCT/PDB showing a higher number of osteoclast-like giant cells (twice), with an abnormal number of nuclei per cell, corroborating its different behaviour in terms of neoplastic properties. We demonstrated that the distinct clinical features of pagetic and conventional GCT are associated with different genetic background, resulting in a specific biochemical and histological behaviour of the tumour.