Denosumab in patients with aneurysmal bone cysts: A case series with preliminary results

Modern treatment of unicameral and aneurysmatic bone cysts

The best treatment of unicameral bone cyst and aneurismatic bone cyst (ABC) is debated in the literature. For simple bone cysts, multiple treatments were proposed from observation only to open curettage. The historical treatment with intraosseous injection of methylprednisolone acetate into the bone cysts nowadays is reduced due to the morbidity of multiple injections and the risk of multiple pathologic fractures until the healing. Different types of treatments for ABC are reported, including surgery, percutaneous treatments, and medical treatments; however, there is currently no consensus on the best approach. The association of curettage, bone graft, and elastic stable intramedullary nail (ESIN) had a success rate of over 85%. Decompressing the cyst wall is more critical for increasing the healing rate than the type of graft used to fill the cavity. In ABC, sclerotherapy offers the advantages of lower invasiveness and morbidity, associated with better functional scores and faster return to full weight-bearing. Moreover, they can be used in challenging locations. Selective arterial embolization is a complex procedure and often requires association with other treatments. Further studies are needed to confirm the effectiveness of denosumab and its side effects on skeletally immature patients. Curettage with adjuvants and autogenous bone grafting still shows promising results and can be used in larger, aggressive defects or superficial lesions. For simple bone cysts, the combination of curettage, bone graft, and ESIN showed the best results. Sclerotherapy for ABC also shows promising results.

Pathological Fractures in Aneurysmal Bone Cysts: A Systematic Review

Background: Aneurysmal bone cysts (ABCs) are osteolytic, non-malignant, vascular lesions of the bone. Pathological fractures can be a manifestation of the ABCs, which occur in about 8% of ABCs. Different treatments have been described in the literature, but, nowadays, an optimal management of the pathological fractures in patients with ABCs is still a matter of debate and there are no standard guidelines for treatment nor any shared indication about the best surgical intervention. The aim of our study is to review the current literature available on this matter exploring and confronting different surgical treatments for pathological fractures in ABC in order to clarify the surgical approach to these patients. Methods: A systematic review of the literature indexed in PubMed, MEDLINE, and Cochrane Library databases was carried out. The Preferred Reporting Items for Systematically Reviews and Meta-Analyses (PRISMA) were followed. Results: A total of 37 articles were relevant and were finally included in the study. In total, we reached a population of 140 patients. Of the 140 patients included in the review, 124 patients (88.6%) underwent curettage surgery, 15 patients (10.7%) underwent en bloc resection surgery. A total of 47% of patients (70) underwent synthesis surgery with a plate, screw, nail, or external fixator. Adjuvant treatments were used in 8.6% of patients (12). Complications involved 20.7% of the patients (29). Conclusions: In conclusion, the treatment of pathological fractures in aneurysmal bone cysts requires careful patient assessment, considering factors such as age, the presence of open growth plates, the location of the lesion, and the surgeon's expertise.

Management of RANKL-mediated Disorders With Denosumab in Children and Adolescents: A Global Expert Guidance Document

CONTEXT

Denosumab is an effective treatment for many receptor activator of nuclear factor kappa-B ligand (RANKL)-mediated disorders but there are potential safety considerations and limited data to guide its use in children and adolescents.

OBJECTIVE

This document seeks to summarize the evidence and provide expert opinion on safe and appropriate use of denosumab in pediatric RANKL-mediated disorders.

PARTICIPANTS

Ten experts in pediatric bone and mineral medicine from 6 countries with experience in the use of denosumab participated in the creation of this document.

EVIDENCE

Data were sourced from the published literature, primarily consisting of case reports/series and review articles because of the lack of higher level evidence. Expert opinion of the authors was used substantially when no published data were available.

CONCLUSION

Denosumab is an effective treatment for RANKL-mediated disorders in children and adolescents but is often not curative and, in some cases, is best used in conjunction with surgical or other medical treatments. Careful multidisciplinary planning is required to define the goals of treatment and expert oversight needed to manage the risk of mineral abnormalities. Substantive, collaborative research efforts are needed to determine optimal treatment regimens and minimize risks.

Denosumab and sclerotherapy for recurrent spinal aneurysmal bone cyst in a child

Aneurysmal bone cyst (ABC) is a non-malignant, locally destructive, blood-filled lesion in the bone that tends to grow aggressively. A young girl presented with a rapid recurrence after aggressive surgery of a large symptomatic sacral-spinal ABC. After a multidisciplinary tumour board, she was successfully treated with sclerotherapy and monthly intravenous denosumab. The patient has maintained asymptomatic for over 36 months now and has returned to full activity and strength. She never required surgery and has had radiologic resolution of the lesions. Treatment of recurrent ABC requires a multidisciplinary team approach. We believe this to be the first report to use this combined therapy to provide an alternative to morbid surgery for children with ABCs.

Using Denosumab as a Nonsurgical Management of Aneurysmal Bone Cysts in the Pelvis

Background

Aneurysmal bone cysts (ABCs) are infrequent, benign, and locally destructive lesions that most commonly occur during the first two decades of life. They usually affect the metaphysis of the long bones, but the pelvis is involved in 8%-12% of the cases. The management of pelvic ABCs is a challenging issue due to difficulties in choosing the appropriate approach, adjacent neurovascular bundles, the risk of intraoperative bleeding with difficulty achieving good hemostasis, and the risk of injury to the hip or sacroiliac joints. Limited data exist concerning the use of denosumab as a non-surgical treatment for pelvic ABCs. Our hypothesis was that denosumab might be an effective and safe solo treatment of cases with ABCs in the pelvis.

Methods

We retrospectively assessed 20 patients with ABCs in the pelvis, who were treated by denosumab as a solo agent without surgery. Patients were assessed regarding disease control, the incidence of recurrence and non-oncological complications, and functional outcome.

Results

The mean follow-up period was 38.5 months. Disease control was achieved in 16 patients (80%), with no local recurrence. Tolerable drug-related complications occurred in 15% of cases. The mean Musculoskeletal Tumor Society score was 92.3%.

Conclusions

Denosumab may provide a reliable option in the nonsurgical treatment of ABCs of pelvic origin with expected lower morbidity than the surgical solution and tolerable complications. Further studies on the safety profile and long-term effects of denosumab especially in skeletally immature patients are required.

Sclerotherapy as a primary or salvage procedure for aneurysmal bone cysts: A single-center experience

BACKGROUND

Aneurysmal bone cysts (ABC) are benign cystic bone tumors of an osteolytic and locally aggressive nature. As an alternative to the primary treatment of choice, which consists of curettage with bone grafting, alternative treatment methods with promising results have been described. At our department, we have, in recent years, used percutaneous sclerotherapy with polidocanol. The objective of this study was to identify the healing rate and safety of sclerotherapy with polidocanol.

AIM

To identify the efficacy and safety of sclerotherapy with polidocanol in primary and recurrent ABC.

METHODS

Twenty-two consecutive patients (median age 12.5 years; range 1-27) with 23 ABCs treated with sclerotherapy with polidocanol from 2016-2021 were included retrospectively. Eleven patients (48%) had undergone different forms of previous treatment with recurrence. Under general anesthesia and fluoroscopic guidance, repeated percutaneous injections of 4mg polidocanol/kg body weight were performed. Through review of the electronic medical records, the following were identified: healing and recurrence rate, number of treatments, gender, age, comorbidity, location of the tumor and side effects / complications, as well as any previous surgery for ABC. The median length of radiographic follow-up was 19.5 mo.

RESULTS

All ABCs except one (96%) showed healing or stable disease after a median of 4 (range 1-8) injections. Complete clinical and radiographic healing was observed in 16 cysts (70%), while partial radiographic healing with resolution of pain was seen in 6 cases (26%) and considered as stable disease. The cyst that failed to heal had previously undergone curettage twice with recurrence. One patient with a large pelvic ABC experienced, right after two injections, a sudden drop in blood pressure, which could quickly be reversed. One patient with a juxtaphyseal ABC in the femoral neck showed a minor limb length discrepancy because of deformity. Beyond that, no complications were observed.

CONCLUSION

Percutaneous sclerotherapy with polidocanol appears to be a safe alternative for treatment of aneurysmal bone cysts. In our series of both primary and recurrent cysts, it showed the ability to achieve healing or stable disease in 22 of 23 cases (96%). Further studies are needed to decide if this provides a long-lasting effect.

Denosumab-Induced Rebound Hypercalcemia Treated With Bisphosphonates in a Pediatric Patient

Denosumab is a RANK-L inhibitor used off-label as a treatment for a variety of pediatric bone disorders, including aneurysmal bone cysts (ABC). Rebound hypercalcemia is a known side effect after denosumab therapy and is more commonly reported in pediatric patients. Although there are no established treatment guidelines, denosumab-induced rebound hypercalcemia is usually managed with a combination of intravenous fluids, diuretics, corticosteroids, denosumab, and/or bisphosphonates. We present the case of a 10-year-old female patient with history of a right sacral ABC treated with denosumab who presented with recurrent episodes of rebound hypercalcemia beginning 3 months after denosumab cessation. After the third hospitalization for hypercalcemia, which was treated with zoledronic acid, normocalcemia was achieved. This case demonstrates an increasingly recognized side effect of denosumab therapy that occurs mainly in skeletally immature patients and presents a possible approach to initial therapy of rebound hypercalcemia with a long-acting bisphosphonate.

Surgical Management and Denosumab for Aneurysmal Bone Cysts of the Spine in an Australian Tertiary Paediatric Centre

Aneurysmal bone cysts (ABC) are rare osteolytic, benign but often locally aggressive tumours of the long bones or vertebrae. For spinal ABC, surgical management, embolisation or sclerotherapy alone often carry high morbidity and/or high recurrence rates. Interruption of receptor activator of nuclear factor-kappa B ligand (RANKL) signalling holds promise as an effective therapeutic strategy for these tumours. We aimed to review the approach to surgical management and evaluate the efficacy and safety of denosumab for ABC of the spine in children. Retrospective review of 7 patients treated with denosumab using a standardised protocol for ABC of the spine in a tertiary paediatric centre. Surgical intervention was only conducted if there was spinal instability or significant neurological impairment. Denosumab 70 mg/m² was given 4-weekly for at least 6 months, followed by 2 doses of zoledronate 0.025 mg/kg, aiming to prevent rebound hypercalcaemia. All patients achieved stability of the spine and resolution of neurological impairment, if present. Six patients achieved metabolic remission and have ceased denosumab without recurrence to date; the other showed clinical and radiological improvement without complete metabolic remission. Three patients developed symptomatic hypercalcaemia 5-7 months after cessation of denosumab, requiring additional bisphosphonate treatment. We present our algorithm for the surgical and medical management of paediatric spinal ABC. Denosumab produced a radiological and metabolic response in all patients, with complete remission in most. Follow-up time was not long enough to evaluate the endurance of response after cessation in some patients. Incidence of rebound hypercalcaemia in this paediatric cohort was high, prompting a change to our protocol.

The role of neoadjuvant denosumab in the treatment of aneurysmal bone cysts: a case series and review of the literature

OBJECTIVE

Aneurysmal bone cysts (ABCs) are benign cystic lesions most commonly occurring in the long bones of pediatric patients. Spinal ABCs may be difficult to resect given their invasive, locally destructive nature, proximity to critical structures such as the spinal cord, and their intrinsic hypervascularity, for which complete embolization is often constrained by radiculomedullary segmental feeders. Denosumab, a monoclonal antibody that binds the receptor activator of nuclear factor kappa B (NF-κB) ligand, has been utilized in the treatment of ABCs most often as a rescue therapy for recurrent disease. Here, the authors present 3 cases of neoadjuvant denosumab use in surgically unresectable tumors to calcify and devascularize the lesions, allowing for safer, more complete resection.

METHODS

This is a single-center, retrospective case series treated at a tertiary care cancer center. The authors present 3 cases of spinal ABC treated with neoadjuvant denosumab.

RESULTS

All 3 patients experienced calcification, size reduction, and a significant decrease in the vascularity of their ABCs on denosumab therapy. None of the patients developed new neurological deficits while on denosumab. Subsequently, all underwent resection. One patient continued denosumab during the immediate postoperative period because a subtotal resection had been performed, with stabilization of the residual disease. No complications were associated with denosumab administration.

CONCLUSIONS

The use of denosumab in unresectable ABCs can cause calcification and devascularization, making safe resection more likely.

A bibliometric research based on hotspots and frontier trends of denosumab

Denosumab is a monoclonal antibody that targets and inhibits the osteoclast activating factor receptor activator for nuclear factor-κB ligand (RANKL). It has been widely used in the treatment of osteoporosis, giant cell tumors of bone, and in the prevention of malignant skeletal-related events (SREs). We collected the research results and related MeSH terms of denosumab from 2011 to 2021 through the Web of Science and PubMed, respectively. The literature was visualized and analyzed by CiteSpace and bibliometric online analysis platforms. The MeSH terms were biclustered using the Bibliographic Co-Occurrence Analysis System (BICOMB) and graph clustering toolkit (gCLUTO). The results show that the number of denosumab-related annual publications had increased from 51 to 215, with the United States leading and Amgen Inc. being the most influential in the past 10 years. Articles published in the Journal of Bone and Mineral Research had the highest total citations. Three scholars from Shinshu University in Matsumoto, Yukio Nakamura, Takako Suzuki, and Hiroyuki Kato, joined the field relatively late but produced the most. The clinical comparison and combination of denosumab with other drugs in the treatment of osteoporosis was the most significant focus of research. Drug withdrawal rebound and management strategies have gained more attention and controversy recently. MeSH analysis revealed eight major categories of research hotspots. Among them, exploring the multiple roles of the RANK-RANKL-OPG system in tumor progression, metastasis, and other diseases is the potential direction of future mechanism research. It is a valuable surgical topic to optimize the perioperative drug administration strategy for internal spinal fixation and orthopedic prosthesis implantation. Taken together, the advantages of denosumab were broad and cost-effective. However, there were still problems such as osteonecrosis of the jaw, severe hypocalcemia, a high recurrence rate of giant cells in the treatment of bone and individual sarcoidosis, and atypical femoral fractures, which need to be adequately solved.

Aneurysmal Bone Cyst (ABC) of the C2 Vertebra

An aneurysmal bone cyst (ABC) is a benign bone lesion commonly found in the younger age group. The principal aim of complete surgical excision to prevent recurrence in an ABC of the C2 vertebra presents a surgical challenge. We report a case of a 13-year-old with an ABC of the C2 vertebra and the strategies in its management surgically and pharmacologically.

Results in the surgical treatment of aneurysmal bone cysts - A retrospective data analysis

BACKGROUND

Aneurysmal bone cysts (ABC) are benign tumors mostly occurring in children and young adults. Different open and minimal invasive surgical approaches have been proposed for the treatment of ABCs and yet no consensus is defined to date. The aim of this study was to retrospectively review data of a large single center series of ABCs with patients treated by open curettage with or without filling of the cavity or en-bloc resection. Questions/purposes We asked: (1) What was the local recurrence rate of ABC after surgical treatment at our institution? (2) What were positive or negative predictors for local recurrence? (3) Was there a benefit from adjuvant burring, phenolization or filling, respectively? (4) Where there changes in recurrence free survival in different time periods of primary surgery?

METHODS

By retrospective data analysis of the Vienna Bone and Soft Tissue Tumor Registry, 123 patients surgically treated for primary aneurysmal bone cysts were identified. After exclusion of 33 patients (27%) due to a postoperative follow up below one year, 90 patients who were treated for primary ABCs between 1986 and 2009 were evaluated. These included 50 males and 40 females with a mean age of 16 years (SD 10 years; range: 2 to 51 years). The mean follow-up was 99 months. (SD 72 months, range: 13 to 329 months) RESULTS: Curettage was performed in 84 patients, while 45 patients received adjuvant phenolization. Local recurrence occurred in 28 patients after a mean time of 16 months, with a corresponding local recurrence free survival (RFS) of 83% after one year, 77% after 2 years and 66% after 5 years. ABCs located in hands and feet (p=0.044) showed a superior RFS, while younger patients (p=0.001) displayed an inferior RFS. Regarding adjuvant surgical techniques, mechanical cavity burring (p=0.004) and filling with autologous cancellous bone graft (p=0.024) showed protective effects on RFS. Patients treated between 1986 and 1999 (n=47) had a higher RFS than patients treated between 2000 and 2009 (n=43, p=0.011), as surgeons and surgical indications changed over time.

CONCLUSION

Although curettage, burring, phenolization and reconstruction with bone grafts came with a relatively high risk of local recurrence, open surgery is still justified in aggressively growing ABCs of critical localizations.

LEVEL OF EVIDENCE

IV; therapeutic study.

Minimally invasive treatment of aneurysmal bone cysts: Systematic literature review

INTRODUCTION

The optimal treatment of aneurysmal bone cysts (ABC) remains controversial. Surgery has long been considered as the treatment that yields the best outcomes. Some authors now prefer using less invasive options as the primary treatment. The primary objective of this systematic literature review was to determine if treatments that are less invasive than surgery are also effective in curing the ABC. The secondary objective was to determine the respective role of each treatment in the therapeutic arsenal.

HYPOTHESIS

Less invasive treatments can replace surgery as the base treatment for ABC.

PATIENTS AND METHODS

A PubMed® search was carried out for this review. The inclusion criteria were ABC treatment without cyst removal, case series, clinical case reports, reviews, publication in French or English. Excluded were articles that described the results of surgical treatment only, cranial or maxillofacial cysts, secondary ABC, duplicates, no abstract available. Based on the first six items of the "MINOR criteria", we selected 42 studies. For each selected study, we analyzed the number of cases, clinical response to treatment, radiological healing, recurrence or failure rate, complications and side effects of the treatment.

RESULTS

This review found that less invasive treatments generate results that are at least as good as surgery, often with fewer complications. Thus, in certain cases, these treatments can be recommended as first-line therapy. This category includes selective arterial embolization, sclerotherapy (alcohol, polidocanol) and injection of demineralized bone matrix.

DISCUSSION

Selective arterial embolization yields good results. While this is a difficult, operator-dependent technique that is not suitable for all ABCs (no identifiable feeding vessel), we recommend it as the primary treatment for spinal ABCs. For ABCs in other locations, sclerotherapy can be used as the primary treatment. However, this treatment becomes inconvenient if the number of injections is too high. Radiation therapy is not a first-line treatment because of its side effects. Bisphosphonates and denosumab can be used when the other treatments are contraindicated.

Primary Aneurysmal Bone Cyst of Nasal Cavity and Sinuses in a Child: Case Report and Literature Review

INTRODUCTION

Aneurysmal bone cysts (ABCs) are a rare benign bone lesion, which are divided into primary and secondary categories, and occur mainly in the vertebra and the long tubular bones. Primary ABCs in the nasal cavity and the sinuses are rare.

CASE PRESENTATION

We reported on a one-year-old boy who suffered from progressive nasal obstruction and intermittent nosebleeds over a period of approximately 1 month. The patient had no history of trauma or surgery. Physical examination showed a red tumor in his right nasal cavity. A magnetic resonance imaging scan showed a multicystic lesion arising from the ethmoid sinus. The lesion was resected under a nasal endoscope without any complications. Histological evaluation confirmed that the lesion was an aneurysmal bone cyst. Because an osteoma was found during the surgery on the cyst, the lesion was considered secondary clinically. However, fluorescence in situ hybridization testing showed a rearrangement of the USP6 (ubiquitin-specific protease 6) oncogene on chromosome 17. No recurrence was observed after 1 year.

CONCLUSION

An ABC of the nasal cavity and sinuses in such a young child is very rare and needs to be further analyzed according to postoperative pathology and combined with a genetic examination to make a diagnosis. Endoscopic sinus surgery is an effective method of treatment for this kind of disease.

Aneurysmal bone cyst and osteoblastoma after neoadjuvant denosumab: histologic spectrum and potential diagnostic pitfalls

The use of denosumab to treat giant cell tumors of bone (GCT) and other giant cell-containing bone tumors has become more common. While the clinicopathologic features of denosumab-treated giant cell tumors of bone have been well-illustrated, descriptions of other denosumab-treated bone tumors are very limited. Surgical pathology files of two institutions and consultation files from two authors were searched for denosumab-treated aneurysmal bone cysts and denosumab-treated osteoblastomas. Clinicopathologic features were reviewed and analyzed. We identified four patients with denosumab-treated bone tumors other than GCT from our surgical pathology and consultation files, including two aneurysmal bone cysts and two osteoblastomas. All were treated with denosumab for 0.5-7.0 (median 4.5) months. Radiologically, denosumab-treated tumors showed decreased size with increased ossification and mineralization on CT and heterogeneous intermediate to hypointense signal on MRI. Histologically, denosumab-treated aneurysmal bone cyst contained thin, elongated, curvilinear, and anastomosing strands of bone with empty lacunae, while denosumab-treated osteoblastoma showed circumscribed nodules of woven bone lined by small osteoblasts. Denosumab-treated aneurysmal bone cyst and osteoblastoma showed treatment-related morphologic changes that can mimic other bone neoplasms. Their recognition requires correlation with the clinical history of denosumab use and radiologic findings.

Destructive Giant Cell Tumor With a Secondary Aneurysmal Bone Cyst of Cervical Spine: A Rare Pediatric Case Report

Spinal giant cell tumor (GCT) and aneurysmal bone cyst (ABC) are infrequent neoplasms of bone. Thirty percent of ABCs are secondary to tumors, such as GCT. We report a rare case of a pediatric cervical spine secondary ABC to GCT that had to be multimodally managed through anterior and posterior surgical approach, embolization, and denosumab treatment leading to a stabilization of the remnant. The case shows the importance of therapeutic strategy decision that depends on the patient and the lesion. 

Doxycycline sclerotherapy of cervical spine aneurysmal bone cysts: single-institution 13-year experience

BACKGROUND

Aneurysmal bone cysts (ABCs) are benign, locally aggressive neoplasms that typically affect patients during their first two decades of life. Curettage with or without bone grafting or adjuvants is the current standard treatment; however, other surgical and medical treatments, such as sclerotherapy, have been reported. Treatment options for cervical spine ABCs are more limited because the proximity of ABCs to critical structures leads to greater risk of spontaneous or treatment-related adverse events, including death.

OBJECTIVE

To retrospectively review all children and young adults with cervical spine ABCs treated with doxycycline sclerotherapy at one referral center to assess its viability as a standalone treatment.

MATERIALS AND METHODS

We retrospectively reviewed the clinical notes and imaging of 16 patients treated with doxycycline sclerotherapy for pathologically proven cervical spine ABCs at our institution between May 2008 and March 2021. All patients underwent image-guided percutaneous doxycycline sclerotherapy to ablate the ABC and stimulate bone formation. We assessed clinical outcomes through chart review and described post-treatment imaging outcomes using modified Neer scoring.

RESULTS

Of the 16 total children and young adults treated, 2 were lost to follow-up, leaving 14 patients with a median age of 14.5 years. Twelve of these 14 patients were successfully treated with doxycycline sclerotherapy for a success rate of 86%. One patient experienced one treatment-related complication (Society of Interventional Radiology [SIR] adverse event classification D), before ultimately being successfully treated. Doxycycline treatment failed in two patients, who then underwent surgical management. Post-treatment imaging of successfully treated cases had a mean modified Neer score of 1.3, whereas post-treatment imaging in failed cases had a mean score of 3.5.

CONCLUSION

Doxycycline sclerotherapy is a viable standalone treatment for cervical spine ABCs because it is safe and effective while avoiding the morbidity associated with open surgical treatments.

Percutaneous Curettage and Local Autologous Cancellous Bone Graft: A Simple and Efficient Method of Treatment for Benign Bone Cysts

BACKGROUND

Several treatment modalities have been reported to minimize the recurrence after surgical treatment of benign bone cysts. In this study, we evaluated local tumor control, recurrence rate, and bone healing of benign bone cysts after treatment with a simple technique, percutaneous curettage and a local autologous cancellous bone graft.

METHODS

Retrospective analysis of the records of 16 patients diagnosed with benign bone cysts between 2003 and 2010. We documented the demographic data, radiographic signs of healing (progressive decrease in radiolucency, remineralisation, ossification, consolidation of the cyst, and reconstitution of the bone), healing rate, postoperative complications, and recurrence.

RESULTS

Seven of the 16 patients (43.75%) were diagnosed with a simple bone cyst (SBC), while nine (56.25%) had an aneurysmal bone cyst (ABC). On average, radiographic signs of healing were present within 3-6 months, but in two patients these signs presented after 16 months. During the follow-up period, there was no difference in the healing rate between patients with SBC and ABC; no signs of deep or superficial wound infection, no postoperative fracture, and no recurrence in any case over an average of 6.3 years of follow-up.

CONCLUSION

Treatment of benign bone cysts (SBC/ABC) with minimally invasive percutaneous curettage and a local autologous cancellous bone graft is a simple and effective modality with a promising outcome in the local control of recurrence and in enhancing bony consolidation.

Mechanisms of acute hypercalcemia in pediatric patients following the interruption of Denosumab

PURPOSE

Denosumab is a fully human monoclonal anti-RANK-L antibody that is clinically used to counteract the bone loss induced by exacerbated osteoclast activity. Indeed, its binding to RANK-L prevents the interaction RANK-L/receptor RANK that is essential for osteoclastogenesis and bone resorbing activity. Although there are many medications available to treat bone loss diseases, including bisphosphonates, Denosumab is highly effective since it reduces the bone erosion. The use in pediatric patients is safe. However, some concerns are related to the interruption of the treatment. Indeed, in this study, we reported hypercalcemia in two pediatric patients and alterations of circulating osteoclast precursors.

METHODS

Peripheral Blood Mononuclear Cells (PBMC) were isolated from two pediatric patients with hypercalcemia after Denosumab interruption and from 10 controls. Cytofluorimetric analysis and in vitro osteoclastogenesis experiments were performed.

RESULTS

Increase of CD16^-CD14⁺CD11b⁺ cells was revealed in PBMC from patients reflecting the enhanced in vitro osteoclastogenesis.

CONCLUSION

Our data suggest that precautions must be taken when Denosumab therapy is interrupted and gradual decrease of dose and/or timing of treatment should be performed. To prevent the onset of hypercalcemia that could be in the discontinuation phase, cytofluorimetric analysis of PBMC should be performed to evaluate osteoclast precursors.

Dramatic response of aneurysmal bone cyst to denosumab: Case report and literature review

Denosumab, a monoclonal antibody that specifically targets cytokine receptor activator of nuclear factor-kappa B ligand (RANKL), is a potentially viable option in resistant aneurysmal bone cysts.

Denosumab in the management of Aneurysmal bone cyst

BACKGROUND

Aneurysmal bone cyst (ABC) is a benign, locally aggressive tumour that arises predominantly in long bones and spine. Following the encouraging results of denosumab use in Giant Cell Tumors (GCT) and the histological similarities between ABC and GCT, the interest on the role of denosumab in the therapeutic arsenal of the most advanced ABC is growing. The purpose of this literature review is to investigate the current state of knowledge about the use of denosumab in ABCs.

METHODS

A literature research was conducted through PUBMED, COCHRANE and GOOGLE SCHOLAR using the keywords "aneurysmal bone cyst" AND "denosumab". Seventeen articles were included.

RESULTS

A total of 43 cases were reported in the literature. There were 23 males, 20 females. The mean age was 15,9±8,1 year. Pain relief and neurological improvement were rapid and sustained. Radiological assessment showed ossification and/or volume reduction in 36/39 patients. Eight patients (18,6%) presented a recurrence after or during denosumab therapy of whom 7 were adults. Adverse events occurred in 11 patients, 5 of them were admitted to the intensive care unit due to hypercalcemia.

CONCLUSION

Denosumab use in non-surgical ABCs has shown a positive impact in pain and neurological symptoms. The oncological outcome remains unclear with a recurrence rate of 18,6% during/after denosumab therapy, mostly in adults. However, regarding the potential clinical benefits, its use might be discussed in the most advanced cases. Further research and clinical trials are mandatory to precise its belonging in the therapeutic arsenal.

Combined Transarterial Embolization and Percutaneous Sclerotherapy as Treatment for Refractory and Nonresectable Aneurysmal Bone Cysts

PURPOSE

To evaluate the safety and effectiveness of combined transarterial embolization and percutaneous sclerotherapy in the treatment of refractory and nonresectable aneurysmal bone cysts (ABCs) as assessed by imaging and clinical outcomes.

MATERIALS AND METHODS

This retrospective, single-center study included 16 consecutive patients (9 women and 7 men; median age, 17 years [range, 6-25 years]) who underwent combined transarterial embolization (using ethylene vinyl alcohol) and percutaneous sclerotherapy (using ethanol gel and polidocanol) for refractory and nonresectable ABCs. The median follow-up was 27.3 months (range, 6.7-47.5 months). Grade of mineralization (5-point Likert scale), grade of fluid-fluid levels (FFLs; 4-point Likert scale), and contrast-enhancing lesion volume were evaluated before and after treatment. The quality of life was determined before and after treatment using the Musculoskeletal Tumor Society (MSTS) score and the 36-Item Short Form Survey (SF-36) health questionnaire.

RESULTS

A mean of 1.6 ± 0.7 transarterial embolizations and 3.2 ± 1.7 percutaneous sclerotherapies were performed. No adverse events were observed. All patients showed either partial or complete response; no patient showed ABC recurrence. The grade of mineralization (3.7 ± 0.7 after therapy vs 1.4 ± 0.5 at baseline; P < .0001) and grade of FFL (3.5 ± 0.8 after therapy vs 1.9 ± 0.6 at baseline; P < .0001) significantly improved after therapy compared with baseline. The mean contrast-enhancing lesion volume significantly decreased after treatment compared with baseline (45.9 mm³ ± 96.1 vs 156.0 mm³ ± 115.3, respectively; P = .0003). The MSTS scores (28.8 ± 1.8 after treatment vs 14.1 ± 8.6 at baseline; P < .0001) and SF-36 findings revealed a significant improvement in the quality of life after treatment compared with baseline, leaving most patients without relevant constraints.

CONCLUSIONS

Combined transarterial embolization and percutaneous sclerotherapy is a minimally invasive, safe, and effective treatment option for refractory and nonresectable ABCs. Treatment fostered bone mineralization and significantly improved patients' quality of life.

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 Efficacy of Denosumab in the Management of a Tibial Paediatric Aneurysmal Bone Cyst Compromised by Rebound Hypercalcaemia

Surgery is the main treatment option for patients with aneurysmal bone cyst (ABC). We report our experience of using denosumab as an alternative treatment in a child with a multiply recurrent and unresectable tibial ABC. The efficacy and safety of denosumab in the paediatric population, and in the treatment of ABC, are still to be fully evaluated. We describe a 13-year-old boy with an extensive and aggressive ABC involving the proximal tibia, which had recurred following multiple previous surgeries. The patient had ongoing severe pain, was unable to weight-bear, and was at significant risk of pathological fracture. En bloc resection and embolization were not deemed viable, and a decision to use denosumab was made. He received 17 doses of subcutaneous denosumab (70 mg/m²) over a 27-month period, at increasing dose intervals. His symptoms significantly improved, and bony consolidation was observed within six months of treatment. He was able to walk without protection and fully weight-bear without any pain by 18 months. With an increase to a six-month dosing interval, the patient presented with a severe, symptomatic rebound hypercalcaemia requiring bisphosphonate therapy. This reoccurred on two further occasions. This case adds to the evidence that denosumab is effective in the treatment of ABC in paediatric patients, but there is a risk of rebound hypercalcaemia. Therefore, patient awareness and biochemical monitoring for rebound hypercalcaemia are essential.

Primary aneurysmal bone cyst of sacrum for adolescent: Eleven cases experience and literature review

The present study is aiming to describe clinical characteristics, surgical flowchart and treatment results of eleven adolescent patients with primary aneurysmal bone cyst (ABC) of sacrum and review in the literature. We retrospectively reviewed eleven young patients with sacral primary ABC, which had the intact clinical and follow-up information at our bone tumor center from 2001 to 2018. The literature review was based on Google Scholar, Medline, EMBASE and Pubmed databases. The search was performed using terms of "aneurysmal bone cyst", "sacral tumor", "sacrum tumor" "spine tumor" and "spinal tumor" for the literature review from 1998 to 2019. There were six male and five female with a mean age of 13 years old at the presentation. The mean follow-up duration was 6.5 years. No patient died of disease and had the pulmonary metastasis. Two patients had wound complications, including onesurgical site infection and one wound dehiscence. No patient had the local recurrence and neurologic deficit. In the literature review, 11 articles were reviewed and 45 cases with sacral primary ABC were included. The rate of local recurrence may be higher than that in our cohort. We proposed our flow chart for preparation of surgery for patients. Preoperative selective arterial embolization and intraoperative aortic balloon occlusion could provide the clear surgical vision and guarantee complete tumor excision by intralesional curettage. Preoperative selective arterial embolization, intraoperative aortic balloon occlusion and complete tumor excision by intralesional curettage can yield satisfactory results with a low rate of recurrence in adolescent patients with a sacral primary ABC.

Validating the management paradigm for pediatric spinal aneurysmal bone cysts to optimize long-term outcomes: an institutional experience

BACKGROUND

The optimal clinical management and outcomes of rare pediatric spinal aneurysmal bone cysts (spABC) is largely anecdotal. Current practice is based on bigger adult series, although given the disparities in spine growth of adults versus children, what impact this difference may have on long-term outcomes has yet to be substantiated. Correspondingly, the aim of this study was to describe the clinical course of all pediatric spABC cases managed at our institution to better understand this.

METHODS

A retrospective cohort study of all pediatric spABC cases presenting to our institution between 1993 and 2017 was performed using a predetermined set of selection criteria. Primary outcomes of interest were treatment modalities and their outcomes, recurrence status, and functional status.

RESULTS

A total of 24 pediatric spABC cases satisfied all criteria. Median age of diagnosis was 13.5 years, with 15 females and 9 males. Radicular pain was the presenting symptom in 21 (88%) cases. Diagnostic biopsy was pursued in 9 (38%) cases, pre-operative embolization in 8 (33%) cases, surgical intervention in 23 (96%) cases, and sclerotherapy in 2 (8%) cases. In terms of surgery, there were no intraoperative complications, and gross total resection (GTR) was achieved in 14 of the 23 (61%) cases. Overall, there were 5 (21%) cases which experienced recurrence by a median time of 8 months after initial surgery, all of which had initial subtotal resection. Median follow-up was 5 years, by which all patients demonstrated excellent functional status.

CONCLUSIONS

There are a number of feasible therapeutic modalities and combinations that can be utilized to maximize control of pediatric spABCs and optimize long-term function similar to that of adults, irrespective of developing versus developed spines. The incidence of recurrence is not negligible, and therefore, rigorous long-term surveillance is highly encouraged, particularly within the first post-operative year following mono-modal non-GTR treatment.

Benign Osseous Tumors and Tumor-Like Conditions

We will provide an imaging-focused discussion of 3 benign bone tumors that do not fit in the categories of cartilaginous tumors or osteoid tumors. We have chosen giant cell tumor of bone, unicameral bone cyst, and fibrous dysplasia. All 3 of these entities are common enough that one does not have to be a musculoskeletal radiologist in a cancer hospital to encounter them occasionally, but none of them should be seen frequently.

Pelvic Aneurysmal Bone Cyst in an Adolescent: A Case Report and Literature Review

An aneurysmal bone cyst (ABC) is a benign but locally aggressive lesion. The challenge in managing pelvic ABC arises from its relative inaccessibility and the presence of nearby neurovascular structures. In this report, we present the case of a 14-year-old female with pelvic ABC and describe the symptoms, signs, and radiographic appearance of the ABC, management, and good outcome of non-surgical management by selective trans-arterial embolization. Although challenging, non-surgical management of pelvic ABCs can result in a favorable outcome. In addition, we reviewed the literature regarding the treatment modalities of pelvic ABCs.

Challenges of denosumab in giant cell tumor of bone, and other giant cell-rich tumors of bone

Purpose of review

Giant cell tumor of bone (GCTB) is an uncommon benign primary bone tumor, consisting of receptor activator of nuclear factor kappa-B (RANK) expressing reactive osteoclast-like giant cells and neoplastic spindle-shaped cells. Denosumab was approved by FDA in 2013 and by EMA in 2014 to treat adults and skeletally mature adolescents with unresectable GCTB or when resection is likely to result in severe morbidity. However, there is much discussion regarding the optimal applied treatment strategy.

Recent findings

Neoadjuvant treatment of GCTB with denosumab can effectively downstage tumors to facilitate less morbid surgery or completely avoid the need for resection, but there is concern about local recurrence postsurgery. Definitive treatment of unresectable GTCB improves symptoms and halts tumor progression. The optimal treatment duration is unclear and long-term treatment is associated with adverse events like osteonecrosis of the jaw (ONJ) and atypical femoral fractures. Denosumab maintenance dose interval is currently being investigated.

Summary

For the related but heterogenous group of giant cell rich tumors of bone, like aneurysmal bone cysts (ABC) and central giant cell granuloma (CGCG), denosumab is a new treatment modality under investigation. Given the effectiveness in GCTB, this could be a promising treatment option for selected patients with advanced disease.

Soft Tissue Special Issue: Giant Cell-Rich Lesions of the Head and Neck Region

Giant cell-rich lesions represent a heterogeneous group of tumors and non-neoplastic lesions, usually arising in bone, which harbor varying number of reactive osteoclastic-type multinucleate giant cells as a common feature. Among these entities, some are confined to the head and neck region (e.g., central giant cell granuloma and mimicking lesions, i.e., peripheral giant cell granuloma and cherubism) or show a relative predilection for this region (e.g., aneurysmal bone cyst and brown tumor of hyperparathyroidism), while others are rare but associated with distinct underlying disease (e.g., giant cell tumor of bone) or histology (e.g., tenosynovial giant cell tumor of the temporomandibular joint and phosphaturic mesenchymal tumor of the jaws) when occurring in the head and neck. Collectively, these lesions pose great challenge in the pathologic diagnosis, which often requires combinatory assessment from the clinical, histopathologic, and/or molecular aspects. This review provides a summary of pertinent clinical and pathologic features and an update of recent molecular and genetic findings of these entities. The considerations in differential diagnosis as well as the effects of the emerging therapeutic RANKL-antagonizing antibody denosumab will also be addressed.

Off-label uses of denosumab in metabolic bone diseases

Denosumab (Dmab), a monoclonal antibody against the receptor activator of nuclear factor-κB (RANK) ligand (RANKL) which substantially suppresses osteoclast activity, has been approved for the treatment of common metabolic bone diseases, including postmenopausal osteoporosis, male osteoporosis, and glucocorticoid-induced osteoporosis, in which the pathway of the RANK/RANKL/osteoprotegerin is dysregulated. However, the imbalance of RANKL/RANK/osteoprotegerin is also implicated in the pathogenesis of several other rare metabolic bone diseases, including Juvenile Paget disease, fibrous dysplasia, Hajdu Cheney syndrome and Langerhans cell histiocytosis, thus rendering Dmab a potential treatment option for these diseases. Dmab has been also administered off-label in selected patients (e.g., with Paget's disease, osteogenesis imperfecta, aneurysmal bone cysts) due to contraindications or unresponsiveness to standard treatment, such as bisphosphonates. Moreover, Dmab was administered to improve hypercalcemia induced by various diseases, including primary hyperparathyroidism, tuberculosis and immobilization. The aim of this review is to summarize existing evidence on off-label uses of Dmab in metabolic bone diseases and provide opinion for or against its use, which should be always considered on an individual basis.

Aneurysmal bone cyst: results of an off label treatment with Denosumab

Background

The treatment of aneurysmal bone cysts (ABCs) has evolved and less invasive methods have been tried. Denosumab is a monoclonal antibody which inhibits osteoclasts. It has been shown to be effective in giant cell tumour of bone (GCT) of bone and hence promises some effect also in ABC. We report on 6 patients treated with Denosumab and compare our results to the cases already published.

Methods

Data of 6 patients with ABCs and patients whose treatment included Denosumab were retrospectively analyzed. Denosumab was used at a dose of 120 mg on days 1, 8, 15 and 29, and every 4 weeks thereafter. In some of these patients the dose was reduced at the end of the treatment. Clinical and radiological responses were evaluated.

Results

In 4 female and 2 male patients with a mean age of 17 years (range: 6–30 years) the lesions were located in the sacrum (2), in distal radius, distal femur, talus and pelvis. One of the sacral lesions healed after 12 months and has stayed stable for 3 years since. The second patient received 2 years of therapy with recalcification, but recurred 1 year later and is under renewed therapy. The pelvic lesion improved but recurred. This patient has a 13-years history of intermittent therapy including surgery, two pregnancies and remains in a stable situation. The lesion of the talus did not improve with Denosumab after surgery and was complicated by destruction of the ankle joint with osteoarthritis. Recurrent lesions of the distal femur and the distal radius, previously treated by curettage and bone grafting healed under Denosumab and have remained stable for 2 and 3 years, respectively. One case of severe hypercalcemia was observed in a 7-year old child 6 months after discontinuation of Denosumab.

Conclusion

Denosumab provides a treatment option for ABCs in anatomically critical locations. Adjuvant application might reduce the rate of local recurrence. In young patients, severe rebound hypercalcemia months after discontinuation of Denosumab may occur.

Aneurysmal bone cyst: A review of 65 patients

Background

Aneurysmal bone cysts (ABC) are benign but locally aggressive lesions. The treatment of ABC has evolved over the years, but curettage with or without local adjuvants still represents the standard. Less invasive methods such as embolization, sclerotherapy or RANKL inhibitors (Denosumab) are also established. The aim of this study was to report and compare the results of a series of patients mainly treated with curettage with and without subsequent phenolization.

Methods

65 patients with the unequivocal diagnosis of primary ABC were treated. 61 of them were located within the bone whereas 4 patients had an ABC of the soft tissues. All patient were treated surgically by means of curettage with or without adjuvants, resection, or with minimally invasive methods such as Polidocanol injections, embolizations or Denosumab treatment. In total 80 procedures had been performed.

Results

Our patients had a mean age of 25.3 ± 16.0 years, ranging from 4 to 74 years. The most common skeletal locations were the pelvis in 23%, the femur in 18%, the tibia in 16% and the spine in 10%. Six lesions were resected and showed no recurrence. 5 patients were treated with polidocanol injections (n = 3) or embolization plus systemic treatment with Denosumab (n = 2). With embolization and Denosumab both patients showed stable disease and required no further treatment. Polidocanol injections resulted in stable disease with no further treatment required in one patient and in subsequent curettage with adjuvant phenolization in two other patients.

In 54 initial curettages 21 were performed with adjuvant phenolization. In this group, 16 lesions healed (76%), 3 showed persistent disease and 2 patients had a local recurrence (9%). Out of 33 patients without phenolization 21 (64%) healed, 3 showed stable persistent disease and 9 (27%) experienced a recurrence. In total we performed 66 curettages, 27 with and 39 without adjuvant phenol treatment. Resolution was achieved in 19 (70%) and 25 (64%) of cases. respectively. Persistent disease was evident in 5 cases each and recurrence in 3 and 9 cases, respectively (n.s.).

Conclusion

Curettage is still the standard of treatment for ABC. Local recurrence does not depend on the use of adjuvant phenol as shown in this and other studies. Minimally invasive methods such as selective embolization and injections of sclerosing agents may result in healing or at least in tolerable persistence of residual lesions but needs repetitive treatments and does not show homogenous results throughout the institutions. Denosumab appears to be an additional option, especially in surgically critical locations such as the spine or the sacrum.

Challenges in the Diagnosis and Treatment of Aneurysmal Bone Cyst in Patients with Unusual Features

Objectives

Aneurysmal bone cyst (ABC) is a benign but locally aggressive tumor. It has several challenging features. The aim of this study is to identify challenges in the diagnosis and treatment of ABC especially in patients with unusual features.

Methods

This retrospective study involved medical record review of primary ABC patients with one or more of the following features: unusual clinical presentation with a mass or a pathological fracture especially at an unusual age, rare locations, radiological findings suggesting other diagnoses especially sarcoma, and a nondiagnostic histopathology of biopsy samples.

Results

25 patients (17 males and 8 females) were included. Most patients were either younger than 10 or older than 20 years. 10 patients presented with a mass or a pathological fracture. Unusual locations include the scapula, the olecranon, the hamate, the calcaneus, and the first metatarsal bone. Extension into the epiphysis occurred in 2 patients with proximal fibula and olecranon ABCs. Two separate synchronous cysts existed in the proximal epiphysis and middiaphysis of one humerus. Radiological imaging suggested other primary diagnoses in 8 patients. Core needle biopsy was diagnostic in only 2 of 7 patients. The main treatment was intralesional resection/curettage with bone grafting. Wide resection was performed in 4 patients. Recurrence rate was 28%. Recurrence risk factors included the following: age less than 10 years, male gender, and proximal femur location. Late recurrence occurred in 3/7 patients. One patient with asymptomatic radiological recurrence showed subsequent spontaneous resolution one year later.

Conclusions

This study presented multiple unusual features of ABC including: unusual age, rare locations, and nondiagnostic radiological and histopathological findings. These features can complicate the diagnosis and management. Given these features, especially with pathological fractures, a well-planned incision, the use of frozen section examination, and the application of either external fixation or plate osteosynthesis for fracture fixation can be recommended.

Denosumab Therapy in the Management of Aneurysmal Bone Cysts: A Comprehensive Literature Review

Aneurysmal bone cysts (ABCs) are uncommon lesions that involve the axial and appendicular bones. Although biologically benign, ABCs have the tendency to assume an aggressive behavior causing local destruction of the underlying bone and neighboring soft tissues. Morphologically, ABCs are composed of cyst-like cavities filled with blood and bounded by an array of diverse cells including fibroblasts, inflammatory infiltrates and osteoclast-like multinucleated giant cells. From a molecular perspective, the osteoclast-like multinucleated giant cells harbor high expression of receptor activator of nuclear factor kappa B (RANK) receptors, whereas the neoplastic stromal cells harbor high expression of RANK ligand (RANKL). The RANK-RANKL interaction has been implicated in the carcinogenesis of ABCs and giant cell tumor of bones (GCTBs). Currently, the optimal management of ABCs remains a hotly debated topic. There are a multitude of treatment modalities (that is, surgery, sclerotherapy, radiotherapy and selective arterial embolization), and each modality has its own benefits, morbidity and risk of complications. The local aggressiveness of ABC and its high rates of relapse following treatment has demanded the march towards discovering more innovative therapies. One of such therapies is denosumab, a monoclonal antibody targeted against the RANKL. Denosumab is already approved by the United States Food and Drug Administration (FDA) for the treatment of adults and skeletally mature adolescents with GCTB that is unamenable to surgery, or initial surgery is anticipated to result in significant morbidity. However, denosumab is not approved by the FDA for the management of ABCs. However, taking into consideration the morphological similarity between GCTBs and ABCs, some treating physicians have logically opted to use denosumab in an off-label manner to treat select ABCs. To the best of knowledge, no study has attempted to summarize the related literature on the use of denosumab in ABCs. Therefore, the primary aim of this study is to narratively review all the available literature about the efficacy and safety of the use of off-label denosumab in the management of patients with ABCs.

Skeletal Morbidity in Children and Adolescents during and following Cancer Therapy

Skeletal abnormalities are common in children and adolescents diagnosed and treated for a malignancy. The spectrum ranges from mild pain to debilitating osteonecrosis and fractures. In this review, we summarize the impact of cancer therapy on the developing skeleton, provide an update on therapeutic strategies for prevention and treatment, and discuss the most recent advances in musculoskeletal research. Early recognition of skeletal abnormalities and strategies to optimize bone health are essential to prevent long-term skeletal sequelae and diminished quality of life in childhood cancer survivors.

Recurrent Aneurysmal Bone Cyst of the Distal Fibula Treated with Denosumab and Curettage

We report the case of a 13-year-old girl with multiple recurrences of an aneurysmal bone cyst of the distal fibula successfully treated with denosumab and curettage. Aneurysmal bone cysts are locally aggressive lesions with high rates of recurrence. The novel use of denosumab with curettage in a long bone showed a favorable outcome with no adverse events or signs of recurrence three years after treatment.