Response of Aneurysmal Bone Cyst to Denosumab

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.

Denosumab in Giant Cell Rich Tumors of Bone: An Open-Label Multicenter Phase II Study

BACKGROUND

Since giant cell tumors of bone (GCTB) and other giant cell rich tumors of bone (GCRTB) share the histological presence of osteoclastic giant cells and expression of RANK/RANKL, we hypothesized that GCRTB will respond similarly to denosumab as GCTB. The primary objective of this study was to determine the efficacy of denosumab in patients with GCRTB that have recurred or require morbid surgery.

METHODS

In this open-label, multicenter, phase II trial, patients with GCRTB were included (June 2018-March 2020). Recruitment was stopped because of low accrual. Patients received denosumab (120 mg) subcutaneously (SC) on day 1 of every 4-week cycle with a loading dose of 120 mg SC on days 8 and 15.

RESULTS

Three patients were enrolled. One withdrew consent before start of study. The remaining patients had central giant cell granuloma of the jawbone (CGCG). Median treatment duration was 15 cycles (range 12-18). In both subjects, improvement in ossification of lesions was seen. Median follow-up was 28.5 months (range 20-37). One patient developed a recurrence for which surgery was performed.

CONCLUSION

Due to critical emerging real-world data of denosumab in GCRTBs, the study was prematurely stopped and not supportive of use of denosumab for this indication. (ClinicalTrials.gov Identifier: NCT03605199).

Quiste óseo aneurismático vertebral agresivo: presentación de un caso y revisión bibliográfica

Introducción: El quiste óseo aneurismático es una lesión seudotumoral lítica, expansiva, compuesta por espacios llenos de sangre separados por tabiques. Representa el 15% de los tumores primarios en la columna, y su presentación de comportamiento agresivo es aún más infrecuente. Se han descrito diferentes opciones terapéuticas en función de su estadio y tasa de recurrencia. Presentamos a un paciente con compromiso neurológico secundario a un quiste óseo aneurismático en la columna torácica, decomportamiento agresivo, que requirió resolución quirúrgica. Conclusión: Las opciones de tratamiento del quiste óseo aneurismático se deben adecuar a cada caso en particular, según sus características. Nivel de Evidencia: IV

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.

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.

Reverse shoulder megaprosthesis replacement for aggressive aneurysm bone cyst of proximal humerus: Case report and literature review

INTRODUCTION

and importance: Wide resection in the surgical treatment of aneurysms bone cysts is often performed in cases where the tumor is large, recurrent, growing, and intensely invasive. Reshaping the defect after tumor removal is a necessary issue to restore shape and maintain function for the patient.

CASE PRESENTATION

A 26-year-old male patient, diagnosed with an aneurysm bone cyst in the proximal humerus, underwent surgery for curettage and bone grafting twice. After surgery, there was still pain in the shoulder area, the tumor progressed aggressively with limited shoulder movement. Based on the imaging re-evaluation, it was shown that the tumor increased rapidly in size, invaded the soft tissue, and completely changed the normal structure of the shoulder joint, and the proximal humerus. We used a reverse shoulder joint with an additional module to restore the bone defect of the tumor and the function of the shoulder joint. Follows-up showed that patient no longer pain in shoulder area, shoulder joint function recovery is progressing well, Musculoskeletal Tumor Society (MSTS) score is 25 & 28, shoulder joint function score according to ASES scale: 80 & 93.33 respectively at 3 months and 6 months after surgery.

CLINICAL DISCUSSION

Aggresive aneurysm bone cyst of proximal humerus is not common and still a challenge to the treatment. Due to the bone and joint destruction, the indication of tumor resection and reconstruct the joint and bone loss is required. Among several solution, reverse shoulder megaprosthesis is a newest one can favor the purpose of our treatment. Up to now, this solution is mainly used to preserving for malignant bone tumor.

CONCLUSIONS

Tumor wide resection with modular reverse shoulder replacement with the modular segment is a reasonable intervention option in cases of large aneurysm bone cysts, with rapid recurrence, aggressive progression, and soft tissue invasion.

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.

Aneurysmal bone cyst of thoracic spine with neurological deficit and its recurrence treated with multimodal intervention - A case report

Background:

Aneurysmal bone cysts (ABCs) are rare, representing about 1% of primary bone tumors, and 15% of all primary spine/sacral tumors. Notably, when they are located in poorly accessible regions such as the spine and pelvis, their management may be challenging. Treatment options include selective arterial embolization (SAE), curettage, en bloc excision with reconstruction, and radiotherapy.

Case Description:

A 16-year-old male presented with 2 months of mid back pain, left-sided thoracic radiculopathy, and left lower limb weakness (MRC – 3/5). MR imaging revealed an expansile, lytic lesion involving the T9 vertebral body, and the left-sided posterior elements resulting in cord compression. He underwent SAE followed by intralesional excision, bone grafting, and a cage – instrumented fusion. ABC was diagnosed from the biopsy sample. Postoperatively, the pain was reduced, and he was neurologically intact. Five months later, he presented with a new lesion that was treated with repeated SAE and three doses of zoledronic acid. At the end of 2 years, the subsequent, MRI and CT studies documented new bone formation in the lytic areas, with healing of lesion; additionally, he clinically demonstrated sustained pain relief.

Conclusion:

Here, we emphasized the importance of surgery for patients with ABC who develop focal neurological deficits. Treatment options should include SAE with bisphosphonate therapy for lesions that recur without neurological involvement.

Aneurysmal Bone Cysts of the Spine in Children: A Review of 18 Cases

STUDY DESIGN

Retrospective study.

OBJECTIVE

The aim of this study was to evaluate the clinical presentation, treatments, outcome, complications, and recurrence rate in the surgical and nonsurgical management of spinal aneurysmal bone cyst (ABC) in a series of 18 pediatric patients.

METHODS

Between 1988 and 2014, we evaluated 18 pediatric patients diagnosed with ABC confirmed by pathology studies. We analyzed clinical and radiological features, non-surgical and surgical treatment, outcome, and complications.

RESULTS

The series included 12 male and 6 female patients with a mean age of 10 years and 4 months, with a mean follow-up of 5 years. Location of the ABC was lumbar in 8, cervical in 7, thoracic in 2, and sacral in 1 case. Axial pain was the most common symptom followed by radicular involvement. Surgery was performed in the presence of spine instability or neurological involvement (tumor resection) and in the remaining, nonsurgical treatment (percutaneous intralesional injection of methylprednisolone and calcitonin). Recurrence was observed in 4 patients requiring reintervention. There were no procedure-related complications.

CONCLUSION

In patients without neurological involvement or spinal instability, nonsurgical treatment is the treatment of choice. Total or subtotal removal combined with posterior instrumented spinal fusion is recommended in cases with a neurological deficit. Both procedures have shown good long-term results.

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.

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.

Use of Denosumab in Children With Osteoclast Bone Dysplasias: Report of Three Cases

Denosumab has been used successfully to treat disease‐associated osteoclast overactivity, including giant cell tumor of bone. Given its mechanism of action, denosumab is a potent potential treatment of other osteoclast bone dysplasias including central giant cell granuloma (CGCG), aneurysmal bone cyst (ABC), and cherubism. Relatively little is known about the safety and efficacy of denosumab in patients with these conditions, especially in children. We report on 3 pediatric patients treated with denosumab over a 3‐year period at UCLA Medical Center (Los Angeles and Santa Monica, CA, USA): a 12‐year‐old with recurrent ABC of the pelvis, a 14‐year‐old with CGCG of the mandible, and a 12‐year‐old with cherubism. All were started on a 1‐year course of 15 doses 120 mg s.c., given monthly with two loading doses on day 8 and 15. All patients demonstrated rapid and pronounced clinical improvement while on denosumab, including a significant reduction in pain and sclerosis of lytic lesions on radiographs. Within 1 month of initiating therapy, 2 patients experienced hypocalcemia (Common Terminology Criteria for Adverse Events [CTCAE] grade 2) and hypophosphatemia, with 1 patient experiencing symptoms. One patient went on to experience symptomatic rebound hypercalcemia (CTCAE grade 4) 5 months after completing therapy, requiring bisphosphonates and calcitonin. For the second patient, we developed a schedule to wean denosumab involving the progressive lengthening of time between doses from 1 to 4 months in 1‐month increments before cessation. We found that denosumab therapy results in significant clinical and radiographic improvement for pediatric patients with nonresectable ABC, CGCG, and cherubism. Problems with serum calcium may be more common in younger patients, with symptomatic and protracted rebound hypercalcemia after cessation of therapy the most significant. We present a potential solution to this problem with progressive spacing of doses. Potential serious adverse events from alterations in calcium homeostasis should be explored in prospective clinical trials. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Aneurysmal Bone Cyst of the Distal Femoral Metaphysis in a Four-year-old Female Patient Presenting with a Pathologic Fracture: A Case Report

Aneurysmal bone cysts (ABCs) are benign osteolytic vascular lesions that are capable of aggressive local expansion and bone destruction. These tumors are most common in adolescent patients and constitute approximately 9% of benign tumors. ABCs can present a diagnostic challenge, as they share several histological and radiographic characteristics with more aggressive lesions, including giant cell tumors and malignant telangiectatic osteosarcomas. The management of ABCs is diverse, but the most common approach includes lesion curettage with bone grafting. Here, we present the case of a large, central ABC of the distal femur in a young, previously healthy female who presented to the emergency room with a pathologic fracture.

Multidisciplinary management of spinal aneurysmal bone cysts: A single-center experience

OBJECTIVE

The management of spinal aneurysmal bone cysts (ABCs) is complex and often requires multimodality therapy, including surgical intervention to stabilize the axial skeleton, and avoid neurologic injury or death. With en bloc resection, ABCs have a recurrence rate of 12%, which increases to >50% with subtotal resection. The use of doxycycline sclerotherapy has been reported to reduce the recurrence rate of non-spinal ABCs to 5% at >24 month follow-up. We retrospectively reviewed our institutional results for sodium tetradecyl sulfate (STS)/doxycycline sclerotherapy and surgical intervention for spinal ABCs, to assess our treatment paradigm for these tumors and inform our future approach to these lesions.

METHODS

Three cervical, two thoracic and two lumbar spine ABCs were treated in seven patients with spine-exclusive disease at our institution from 2011 to the present. The most common presenting complaint was pain. Each patient was retrospectively reviewed for clinical symptomology, number of treatments, technique and clinical follow-up. Qualitative assessment of improvement was based on the most recent clinical evaluation.

RESULTS

The cohort underwent a mean of three treatment sessions (range 2-15). All were treated with STS and/or doxycycline. Five patients underwent surgical intervention at some point, either before or following sclerotherapy. After the last sclerotherapy session, four patients reported stable or improved pain symptoms, while two reported progressive pain that required surgical intervention for that indication. One patient, who underwent both multiple rounds of sclerotherapy and surgical resection, died due to acute on chronic cervical spine collapse with cord compression and inability to control disease.

CONCLUSION

We report our experience in the treatment of spinal column ABCs. Stabilization or improvement in pain was seen in four patients, while the remainder had progressive disease. Our multidisciplinary approach allows patients to receive the most appropriate treatment at presentation and thereafter, for symptom amelioration or spinal stability. Important future goals are to quantitatively assess changes in symptoms over time and to incorporate a reproducible radiographic endpoint for the assessment of treatment efficacy.

Primary Bone Tumor of the Spine-An Evolving Field: What a General Spine Surgeon Should Know

STUDY DESIGN

A narrative review of the literature.

OBJECTIVE

This article reviews the general principles of treatment and investigation for primary bone tumors of the spine. Furthermore, it explores the emerging alternatives.

METHODS

A review was performed using Medline, Embase, and Cochrane databases.

RESULTS

Primary bone tumors of the spine are rare entities that general spine surgeons may encounter only a few times in their career. The treatment algorithm of these complex tumors is filled with nuances and is evolving constantly. For these reasons, patients should be referred to experienced tertiary or quaternary centers who can offer a comprehensive multidisciplinary approach. For most malignant spinal bone tumors, surgery remains the cornerstone of treatment. Respecting oncologic principles has been associated with improved survival and decreased local recurrence in multiple settings. However, even in experienced centers, these surgeries carry a significant risk of adverse events and possible long-term neurologic impairment. The associated morbidity of these procedures and the challenges of local recurrence have encouraged professionals caring for these patients to explore alternatives or adjuncts to surgical treatment.

CONCLUSIONS

Over the past few years, several advances have occurred in medical oncology, radiation oncology and interventional radiology, changing the treatment paradigm for some tumors. Other advances still need to be refined before being applied in a clinical setting.

Denosumab: A potential new treatment option for recurrent Aneurysmal Bone Cyst of the spine

ABCs are expansile osteolytic lesions typically containing blood-filled spaces separated by fibrous septae. Standard treatment includes surgical resection or curettage and packing; however, for some spinal lesions, the standard approach is not optimal. One therapeutic strategy is to treat spinal ABC with an agent that targets a pathway that is dysregulated in a disease with similar pathophysiology. Denosumab, a human monoclonal antibody to RANKL is effective in the treatment of GCT's. Spinal ABCs are a therapeutic challenge and local recurrence is a concern. We report a case of aggressive recurrent ABC of dorsal spine in a 14-year old female with progressive neurologic deficit who underwent surgical excision and decompression with a recurrence in a short period for which a decompression and fixation was done. She had a recurrence after an asymptomatic period of 6 months and neurologic worsening. Having ruled out use of embolization and radiotherapy, a remission was achieved by treatment with Denosumab using the regimen for GCTs for a duration of 6 months. Follow-up MRI and CT scans at 24 months following inception of Denosumab depicted complete resolution and no recurrence. We conclude that Denosumab can result in symptomatic and radiological improvement in the recurrent locally aggressive ABC and may be useful in selected cases. Long-term results are mandatory to confirm the efficacy of Denosumab and to evaluate local recurrence after stopping Denosumab.

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.

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.

Complete resolution of a cervical spine aneurysmal bone cyst after single session of endovascular embolization: Case report

Treatment options for aneurysmal bone cysts include intralesional curettage, segmental excision, en bloc resection and endovascular embolization. The most commonly used treatment is intralesional curettage and selective arterial embolization is normally an adjunctive therapy, not a definitive treatment. We report a case of a C1 lateral mass aneurysmal bone cyst treated with a single session of endovascular embolization. Long-term follow up demonstrated complete resolution of the cyst. A study of aneurysmal bone cyst embolization was conducted and the key points for obtaining maximal devascularization of the cyst along with embolic material and technique are discussed.

Tumor de células gigantes espinal en niños. Reporte de dos casos. [Spinal giant cell tumor in children. Report of two cases]

El tumor de células gigantes espinal es una neoplasia de estirpe benigna y comportamiento local agresivo, de presentación rara en la población pediátrica. El dolor asociado al compromiso neurológico es la presentación típica en niños. La resección amplia del tumor y la descompresión de los elementos neurales asociada a fusión instrumentada permiten obtener una columna estable, preservar o restaurar la función neural y evitar la recidiva tumoral. Se presentan dos pacientes con tumor de células gigantes espinal en esqueleto inmaduro, sometidos a resección y estabilización mediante artrodesis instrumentada, sin recidiva en el posoperatorio alejado. La presentación clínica, la edad de los pacientes y los resultados quirúrgicos a largo plazo hacen de extremo valor el reporte de estos casos en esqueletos inmaduros.

Denosumab treatment in aneurysmal bone cyst: Evaluation of nine cases

BACKGROUND

Aneurysmal bone cyst (ABC) is a benign bone tumor. Curettage and bone grafting is the common treatment. Here, we retrospectively evaluate nine patients treated with denosumab.

PROCEDURE

Nine patients with ABC, mostly pelvic and vertebral, treated with denosumab were analyzed retrospectively. A 70 mg/m² denosumab dose was used weekly in the first month, and then monthly. Clinical and radiological responses to treatment were evaluated.

RESULTS

In all patients, clinical symptoms including pain and limping regressed completely within 3 months. Radiological evaluation revealed changes in lesion size and content. In six patients, overall volume reduction in the range of 18-82% was detected. Decreases in the size and number of cysts were detected in eight patients. In five patients, fat signal appeared on follow-up imaging. No major side effects were observed during treatment. Median follow-up time after treatment was 15 months. At 5 months, severe hypercalcemia was observed in two patients due to rebound increase in osteoclastic activity. Subsequent to denosumab treatment, three patients underwent surgery for clinical or radiological recurrence.

CONCLUSIONS

Our results showed that denosumab provided a meaningful clinical and radiological improvement in ABC. It may be a treatment option, especially in spinal and pelvic tumors with potentially high surgical morbidity. However, late rebound hypercalcemia may restrict its use. Studies with more cases are required for routine use of denosumab in ABC.

Treatment of the aneurysmal bone cyst by percutaneous intracystic sclerotherapy using ethanol ninety five percent in children

INTRODUCTION

Aneurysmal bone cyst (ABC) is a benign intraosseous lesion filled with blood that can determine a blowout distension of the bone. The purpose of this study is to evaluate the efficacy of sclerotherapy by percutaneous intralesional administration of ethanol 96% for the treatment of this pathology in paediatric patients.

METHOD

The retrospective study includes 17 paediatric patients with ABC who were treated by repeated intracystic injection with ethanol 96%, 1 ml/kg, in our clinic between December 2015 and July 2017. Fluoroscopic guidance was used to inject the cyst with contrast agent. The mean follow-up period was 11 months.

RESULTS AND DISCUSSION

All cysts are healed or are in the healing process. The mean age was 11 years old. Seven patients needed three repeated injections and ten patients needed two injections until healing. We observed a mean reduction in the size of the lesions, measured on plain X-rays, of 68%. The complications that were observed included the following: dizziness after injection, skin pigmentation at the injection site, local inflammatory reaction, and pain after injection. The current study approves the importance of this minimally invasive treatment with no recurrence after a follow-up of 19 months. The healing rate was 100%. A limitation of this study consists in the small number of patients.

CONCLUSION

Sclerotherapy with ethanol 96% is a useful method for the treatment of ABC. It is a minimally invasive method, with no major complications, which lowers the risks of open surgical intervention and has a good rate of success.

Denosumab: a potential treatment option for aneurysmal bone cyst of the atlas

PURPOSE

Aneurysmal bone cysts (ABCs) of spine are conventionally treated with en-bloc resection or intralesional excision/curettage and reconstruction or filling of defects with bone cement. For the treatment of upper cervical ABCs, en-bloc resections are often not desirable considering the risk/benefit ratio while the risk of recurrence after intralesional excision is high. Hence, alternative management options are often necessary. We describe our clinical experience with one such treatment alternative-denosumab for the treatment of ABC of Atlas.

METHODS AND RESULTS

We present a case of 16-year-old boy who presented with neck pain and restriction of neck movements. A large lytic lesion with multiple fluid-fluid interfaces involving vertebral arch of atlas was identified on further imaging. There was destruction of right lateral mass and the lesion was found encasing the right vertebral artery. Core needle biopsy confirmed the diagnosis of ABC. With no visible CT response after first session of intra-lesional injection of Calcitonin and Methylprednisolone, the patient was treated with denosumab (120 mg SC once-a-month) for a period of 12 months. His symptoms resolved within 7 months of onset of treatment and serial CT scans over 12-month treatment period showed complete ossification of the lesion. Further there was no evidence of recurrence at 12 months after completion of treatment.

CONCLUSION

Our case report contributes to the accruing evidence on the effectiveness of denosumab for the treatment of spinal ABCs. However, long-term safety, risk of recurrence, optimal duration of treatment and consistency of denosumab are yet to be determined.

Giant Cell-Containing Tumors of Bone

Giant cell-containing tumors of bone are characterized morphologically by the presence of numerous osteoclastic giant cells. Correlation of clinical, radiologic, and laboratory findings is required for accurate histopathologic diagnosis and treatment of a giant cell-containing tumor of bone. In differential diagnosis, it is particularly important to note the age of the patient and the skeletal location of the lesion. This article considers the range of neoplastic and nonneoplastic lesions, which histologically contain numerous osteoclastic giant cells, and focuses on several lesions that frequently enter into the differential diagnosis.

Efficacy and Safety of Selective Arterial Embolization in the Treatment of Aneurysmal Bone Cyst of the Mobile Spine: A Retrospective Observational Study

STUDY DESIGN

A retrospective observational study.

OBJECTIVE

Our aim is to define the efficacy and safety of serial selective arterial embolization (SAE) in the treatment of aneurysmal bone cysts (ABCs), to explore potential treatment alternatives, and to define a therapeutic algorithm.

SUMMARY OF BACKGROUND DATA

ABC is a benign lesion with an unpredictable behavior. Its treatment is challenging especially in poorly accessible surgical areas, such as spine and pelvis. Currently, the first-line treatment of ABC is repeated SAE until healing. Other options have been used with variable success rates.

METHODS

From January 2004 to September 2015, 23 patients affected by ABC of the mobile spine have been treated with SAE and prospectively followed up by computed tomographic scan and magnetic resonance imaging. Signs of neurological deficit, complications, healing of the lesion, and clinical outcomes were registered.Signs of healing are defined as peripheral sclerotic bone rim formation, decrease of the ABC mass, disappearance of the double content image, and bone formation inside the ABC mass, associated with remission of pain.

RESULTS

Twenty-three patients underwent SAE according to the protocol. Seventeen patients have healed. The number of procedures necessary to obtain healing (clinical and radiographic) varied from 1 to 10. No complication occurred during the procedure. Follow-up time ranged from 5 to 120 months after the last angiographic procedure. All 17 patients had complete relief of pain symptoms. Six patients did not respond to SAE, presenting a progressive clinical and radiographic worsening, and underwent other medical or minimally invasive treatments.

CONCLUSION

Our study confirms the safety of SAE. The efficacy of the treatment was however lower than expected. SAE is indicated when pathological fracture or signs of cord damage are not detected. Infiltration with autologous bone marrow concentrate or administration of Denosumab is under investigation as alternative choices of treatment.

LEVEL OF EVIDENCE

4.

Denosumab: Current Use in the Treatment of Primary Bone Tumors

Denosumab, a human monoclonal antibody that inhibits bone resorption by binding on the receptor activator of the nuclear factor kappa-β ligand, has recently emerged as an additional option in the treatment of musculoskeletal osteolytic tumors. This article focuses on the recent literature regarding the effectiveness of denosumab in the management of giant cell tumor, multiple myeloma, aneurysmal bone cyst, and osteosarcoma. The mechanism of action of denosumab in the management of these tumors and the associated side effects are discussed in detail. [ Orthopedics. 2017; 40(4):204-210.].

Secondary Aneurysmal Bone Cyst of the Scapula Treated by CT Guided Percutaneous Polidocanol Injection - A Case Report

Aneurysmal Bone Cyst (ABC) is a rare benign tumour, usually affecting early age group and at the metaphysis of long bones. Scapular ABC's are even more rare, especially successfully treated cases. Standard treatment methods like curettage have high recurrence rates hence, adjuvant therapy may be required to avoid recurrence. Polidocanol sclerotherapy is becoming popular because of its safety and efficacy and is being tried successfully for both active as well as aggressive primary ABC of size 3-5cm. We used the same principle in a large secondary ABC of the scapula, which to the best of our knowledge has not been yet reported. The index case is that of a 16-year-old girl who presented with severe pain and swelling of right scapula for 6 months duration with painful limitation of shoulder movements. After extensive evaluation, we diagnosed ABC of the scapula secondary to fibrous dysplasia which was successfully managed by CT guided percutaneous polidocanol sclerotherapy. One year after the injection, patient is asymptomatic with excellent radiological outcome. Polidocanol is an effective alternative to conventional methods since, it precludes functional disabilities like joint stiffness and shortening which are common with other methods.

Current management of aneurysmal bone cysts

Aneurysmal bone cysts (ABCs) are benign bone lesions arising predominantly in the pediatric population that can cause local pain, swelling, and pathologic fracture. Primary lesions, which constitute roughly two thirds of all ABCs, are thought to be neoplastic in nature, with one third of ABCs arising secondary to other tumors. Diagnosis is made with various imaging modalities, which exhibit characteristic features such as "fluid-fluid levels," although biopsy is critical, as telangiectatic osteosarcoma cannot be excluded based on imaging alone. Currently, the standard of care and most widely employed treatment is intralesional curettage. However, tumor recurrence with curettage alone is common and has driven some to propose a multitude of adjuvants with varying efficacy and risk profiles. Historically, therapies such as en bloc resection or radiation therapy were utilized as an alternative to decrease the recurrence rate, but these therapies imposed high morbidity. As a result, modern techniques now seek to simultaneously reduce morbidity and recurrence, the pursuit of which has produced preliminary study into minimally invasive percutaneous treatments and medical management.

Benign Tumors of the Spine: Has New Chemotherapy and Interventional Radiology Changed the Treatment Paradigm?

STUDY DESIGN

Clinically based systematic review.

OBJECTIVE

To determine the role of (A) medical treatment and (B) interventional radiology as either adjuvant or stand-alone treatment in primary benign bone tumors of the spine.

METHODS

A multidisciplinary panel of spine surgeons, radiation oncologists, and medical oncologists elaborated specific focused questions regarding aneurysmal bone cyst, giant cell tumor, and osteoid osteoma. Denosumab, bisphosphonate, interferon, bone marrow aspirate, doxycycline, thermal ablation, and selective arterial embolization were identified as areas of interest for the article. A systematic review was performed through MEDLINE and EMBASE. Recommendations based on the literature review and clinical expertise were issued using the GRADE system.

RESULTS

The overall quality of the literature is very low with few multicenter prospective studies. For giant cell tumor, combination with Denosumab identified 14 pertinent articles with four multicenter prospective studies. Nine studies were found on bisphosphonates and six for selective arterial embolization. The search on aneurysmal bone cyst and selective arterial embolization revealed 12 articles. Combination with Denosumab, Doxycycline, and bone marrow aspirate identified four, two, and three relevant articles respectively. Eleven focused articles were selected on the role of thermal ablation in osteoid osteoma.

CONCLUSION

Alternative and adjuvant therapy for primary benign bone tumors have emerged. Their ability to complement or replace surgery is now being scrutinized and they may impact significantly the algorithm of treatment of these tumors. Most of the data are still emerging and further research is desirable. Close collaboration between the different specialists managing these pathologies is crucial.

LEVEL OF EVIDENCE

N/A.

Primary osseous tumors of the pediatric spinal column: review of pathology and surgical decision making

Spinal column tumors are rare in children and young adults, accounting for only 1% of all spine and spinal cord tumors combined. They often present diagnostic and therapeutic challenges. In this article, the authors review the current management of primary osseous tumors of the pediatric spinal column and highlight diagnosis, management, and surgical decision making.