RARE DISEASE
Aneurysmal bone cyst
Aneurysmal bone cyst
Aneurysmal bone cyst
Drug discovery
0
drugs
With orphan designations
Overview
Aneurysmal bone cyst (ABC) is a benign, locally aggressive bone tumor characterized by blood-filled cystic spaces and USP6 gene rearrangements in 70% of primary cases [1][11]. Most occur in children and adolescents, presenting as pain, swelling, or pathological fractures [1][13]. Primary ABCs arise de novo, while 30% are secondary to other bone lesions like giant cell tumors [6][9]. Recurrence rates reach 20-30% after curettage [7][13].
Burden
Recurrence risks (20–70%) often necessitate repeated interventions [9][13]. Spinal ABCs may cause neurological deficits, while aggressive lesions risk pathological fractures and growth disturbances [6][12]. Treatment-related morbidity includes intraoperative blood loss and postoperative complications [6][16].
Therapies
— Primary: Curettage with adjuvants (high-speed burr, phenol, cryotherapy) ± bone grafting [3][7][15].
— Minimally invasive options: Percutaneous sclerotherapy (polidocanol, doxycycline) or embolization for complex/spinal lesions [3][8][15].
— Medical therapies: Denosumab or bisphosphonates for unresectable cases, though hypercalcemia risks limit pediatric use [3][15].
Categories: rare bone diseases, rare neoplastic diseases
Research Papers
1,018 drug discovery papers about Aneurysmal bone cyst, with 1 first-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
1,018 drug discovery papers about Aneurysmal bone cyst, with 1 first-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
categories:
Small molecules
small molecules
2026-07-22 | Polidocanol Sclerotherapy Plus Adjuvant Autogenous Bone Marrow Injection for Management of Aneurysmal Bone Cyst: A Prospective Study.
Aneurysmal bone cysts (ABCs) are benign bone lesions that exhibit localized destructive growth. Conventionally, most patients are treated with curettage and bone grafting. Alternatively, percutaneous treatment using selective arterial embolization and sclerotherapy had been successfully used with promising results. Adjuvant use of bone marrow injection alone or with other agents for treatment of bone cysts was previously used. The aim of this work is to assess the clinical outcome of polidocanol sclerotherapy with adjuvant autogenous bone marrow injection for management of ABCs. The present prospective study was conducted on 20 patients with ABCs diagnosed on the basis of clinical and radiological findings. All patients were managed using polidocanol sclerotherapy followed by adjuvant autogenous bone marrow injection. Pain was evaluated using Visual Analog Scale (VAS). Radiographic evaluation was performed using plain radiographs. All patients were followed for 30 months after the last treatment session. The present study was conducted on 20 patients with an age of 10.2 ± 4.4 years (range: 3.0-20.0 years). They comprised 12 males and 8 females. VAS for pain improved from 6.2 ± 1.4 at baseline to 0.3 ± 0.5 (p < 0.001) at the end of follow-up. Radiologically, cyst volume significantly decreased from 79.9 ± 26.3 ml to 2.0 ± 2.1 ml (p < 0.001). Reported complications included recurrence (5.0%), ecchymosis (10.0%), and nausea and vomiting (5.0%). Use of polidocanol sclerotherapy followed by adjuvant autogenous bone marrow injection for management of ABCs is highly effective with adequate safety profile.
2026-07-16 | Aneurysmal bone cyst of the calcaneus: a case report and review of the literature.
Aneurysmal bone cysts (ABCs) are locally destructive, blood-filled benign bone lesions traditionally regarded as reactive rather than true neoplastic lesions. ABCs typically affect the proximal humerus, distal femur, proximal tibia, and spine. Involvement of the calcaneus is rare, representing approximately 1.6% of reported cases. A PubMed search identified nine publications describing 22 cases of calcaneal ABCs. Here, we report a rare case of ABC arising in the calcaneus and review the relevant literature. A 17-year-old Japanese male with no relevant medical history presented with left calcaneal pain and gait disturbance. The patient underwent curettage with phenol-ethanol ablation and artificial bone packing (β-tricalcium phosphate [β-TCP], AFFINOS®, KURARAY Co., Tokyo, Japan). No local tumor recurrence was observed at the 36-month follow-up. This case highlights a rare ABC arising in the left calcaneus of a 17-year-old Japanese male, with no recurrence after 36 months. Although adjuvant therapy was performed in this case, additional cases are required to clarify its necessity in the management of calcaneal ABC.
2026-07-13 | Percutaneous Sclerotherapy of Diaphyseal Aneurysmal Bone Cyst of Tibia in a Child
Abstract Aneurysmal bone cysts (ABCs), though benign, are locally aggressive. ABCs may cause symptoms such as painful limping and may lead to pathological fractures. Traditional surgical methods of treatment have an increased risk of recurrence, morbidity, and longer hospital stays. While selective arterial embolization can be performed, it may not be feasible in resource-limited conditions. Percutaneous image-guided sclerotherapy of the ABCs can be an effective treatment option. This case report describes a minimally invasive technique for percutaneous sclerotherapy of a tibial diaphyseal aneurysmal bone cyst using a combination of polidocanol and gelatin sponge slurry as a cost-effective and minimally invasive method.
2026-07-09 | Aneurysmal Bone Cyst of the Distal Tibia Treated by Intralesional Curettage and Cementation: A Case Report
Introduction: Aneurysmal bone cyst (ABC) is a benign but locally aggressive osteolytic bone neoplasm characterised by blood-filled, multi-septated cavities. It predominantly affects the metaphyseal regions of long bones in children and young adults. Distal tibial involvement is uncommon and presents specific surgical challenges due to the proximity of the ankle joint and physis. We report a case of a large ABC of the distal tibia treated successfully with intralesional curettage and polymethylmethacrylate (PMMA) cementation. Case Presentation: A 30-year-old patient presented with progressive pain and swelling of the right ankle. Plain radiographs and computed tomography (CT) revealed a large, expansile, multi-lobulated metaphyso-epiphyseal osteolytic lesion of the distal tibia measuring 40 × 26 mm in cross-section with a 38 mm craniocaudal extent, cortical thinning, and no soft tissue invasion. Magnetic resonance imaging (MRI) demonstrated pathognomonic fluid-fluid levels on T2-weighted sequences with moderate peripheral gadolinium enhancement, consistent with ABC. Intralesional curettage and PMMA cementation were performed. Histopathological examination confirmed the diagnosis. At final follow-up, the patient achieved complete resolution of pain and full, pain-free ankle range of motion with no recurrence. Conclusion: ABC of the distal tibia is a rare but treatable periarticular lesion. MRI with fluid-fluid levels is the cornerstone of preoperative characterisation. Intralesional curettage combined with PMMA cementation offers immediate mechanical stability, facilitates recurrence surveillance, and yields excellent functional outcomes.
2026-07-06 | Intracranial aneurysmal bone cysts in association with fibrous dysplasia: Case report and scoping review of case reports.
Aneurysmal bone cyst (ABC) in association with craniofacial fibrous dysplasia (FD) is rare and may mimic aggressive change when a previously indolent lesion enlarges rapidly. We report an intracranial/cranial vault case and map published cranial vault/skull-base cases. A 16-year-old girl presented with a rapidly enlarging left parietal mass, headache, intermittent diplopia, and vertigo. Magnetic resonance imaging demonstrated expansive craniofacial/skull-base FD with a multiloculated osteolytic parietal component containing hemorrhagic fluid-fluid levels, suggestive of ABC. Preoperative embolization was followed by resection and cranial reconstruction. Histopathology confirmed FD with a focal ABC component. At 3-year follow-up, the patient had no recurrence of the resected lesion. A scoping review was performed using structured PubMed/MEDLINE and Embase searches from database inception to December 2025, limited to articles in English or Spanish, including case reports/series of ABC in association with FD involving the cranial vault and/or skull base. Thirty-three individual cases were identified: 57.6% male, mean age 18.6 years (range 6-40). FD was polyostotic in 48.5%, monostotic in 24.2%, and unspecified in 27.3%. The frontal bone was the most frequent site (15.2%). The cystic ABC pattern predominated (75.8%). Follow-up was reported in 54.5% (mean 9.6 months among reported cases). ABC should be considered when craniofacial FD shows rapid enlargement, pain, neurological/neuro-ophthalmologic symptoms, or fluid-fluid levels. Diagnosis requires clinicoradiologic-pathologic correlation. Management should be individualized, often favoring embolization and maximal safe resection with reconstruction and long-term surveillance.
cell therapies
2026-07-21 | Minimally Invasive Treatment of Aneurysmal Bone Cysts Utilizing a Modified Sclerograft Technique.
Aneurysmal bone cysts (ABCs) are locally aggressive expansile bone tumors that typically present near the metaphysis and are commonly encountered in the pediatric population. This study presents the results of a single staged procedure, which is a modification of the Sclerograft procedure (chemical sclerotherapy combined with regenerative bone grafting) used to treat unicameral bone cysts (UBCs), as an alternative treatment paradigm. This retrospective, single-institution study included patients with MRI-confirmed primary aneurysmal bone cysts of the appendicular skeleton treated between 2020 and 2025. Eligible patients underwent mechanical disruption with doxycycline sclerotherapy (± cryoablation) and regenerative bone grafting. Demographics, lesion characteristics, prior treatments, imaging, and clinical outcomes were analyzed. The final cohort included 27 patients (15 females, 12 males) with a mean age of 10.6 years. The primary outcome was the reintervention rate. Patients underwent a median of 1 procedure (range 1-3; mean 1.33) over a median follow-up of 1.88 years (range 0.5-5.8 years). 7 of 27 (25.9%) required at least one additional procedure due to radiographic (Modified Neer Grade 3-4) and symptomatic recurrence. Median time to retreatment was 12.2 months (IQR 6.8-19.4). Radiographs were the primary follow-up imaging modality (92.6%). The modified Sclerograft technique is a feasible, single-session treatment option for primary aneurysmal bone cysts with promising results that warrant further study as a possible alternative to the historical paradigm of serial sclerotherapy. Utilizing regenerative bone graft facilitates bone formation and permits the majority of follow-up to be performed with plain radiographs.
2026-07-10 | Aneurysmal Bone Cyst of the Proximal Humerus Managed with En Bloc Resection, Fibular Strut Grafting, and PHILOS Fixation: A Case Report.
Aneurysmal bone cyst (ABC) is a benign, locally aggressive osteolytic lesion characterized by expansile blood-filled cavities separated by fibrous septa affecting the metaphyseal region of long bones in young individuals and accounting for approximately 1-2% of primary bone tumors. Proximal humerus involvement presents with reconstructive challenges due to the need to preserve shoulder biomechanics and rotator cuff function. A 28-year-old female presented with progressive pain and swelling of the left shoulder for 5 months, with restricted overhead activity. Imaging showed an expansile metaphyseal lytic lesion (Capanna Type II). A prior biopsy was suggestive of ABC. Two trials of selective arterial embolization failed to improve clinically and radiologically. Management included repeat pre-operative angio-embolization followed by en bloc resection. The defect was reconstructed using a 15-cm non-vascularized ipsilateral fibular strut graft stabilized with a PHILOS plate. Histopathology confirmed the diagnosis of ABC. Serial follow-up demonstrated graft incorporation and union with restoration of painless full shoulder motion. Large proximal humerus ABCs require meticulous oncologic clearance combined with stable structural reconstruction. Pre-operative embolization followed by en bloc excision, fibular strut grafting, and PHILOS fixation provides satisfactory functional and radiological outcomes.
2026-07-10 | Aneurysmal Bone Cyst of Calcaneum in a Young Adult: A Rare Case Report.
Aneurysmal bone cyst (ABC) is a benign but locally aggressive osteolytic lesion that commonly affects long bones and vertebrae. Involvement of the calcaneum is rare and presents a unique diagnostic and therapeutic challenge due to its weight-bearing nature. A 23-year-old male presented with pain in the left heel for 6 months, insidious in onset and progressive in nature, aggravated by weight bearing. Clinical examination revealed localized tenderness over the calcaneum. Radiographs showed an expansile osteolytic lesion with cortical thinning. Magnetic resonance imaging demonstrated a multiloculated cystic lesion with multiple fluid-fluid levels suggestive of ABC. The patient underwent extended curettage and autologous cancellous bone grafting and bone substitute. Histopathological examination confirmed the diagnosis of ABC. At 6 months follow-up, the patient was asymptomatic with no evidence of recurrence. Calcaneal ABC is a rare entity that should be considered in young patients presenting with chronic heel pain. Imaging aids in diagnosis, but histopathology is mandated. Extended curettage with bone grafting is an effective treatment option with good functional outcomes and low recurrence rates.
2026-05-27 | Single-Stage Combined Embolization and Structural Allograft Reconstruction for Proximal Humerus Aneurysmal Bone Cysts in Children.
Aneurysmal bone cysts (ABCs) of the proximal humerus in children are rare, locally aggressive lesions associated with substantial recurrence rates and risk of structural instability. Conventional treatment by curettage and bone grafting is often limited by recurrence, while selective arterial embolization (SAE) alone may not provide sufficient structural support. This study evaluates a single-stage treatment strategy combining embolization and structural reconstruction to address both the vascular and mechanical components of the disease. A retrospective analysis was performed on 12 pediatric patients (median age 9 years) with proximal humerus ABCs treated between 2020 and 2024. All patients underwent a standardized single-stage protocol consisting of preoperative SAE, intralesional resection with high-speed burr, and reconstruction using an allogeneic fibula graft combined with cancellous bone augmentation. Radiological consolidation, recurrence, and functional outcomes were assessed. Associations between prior surgery, cyst size, and recurrence were analyzed. Primary consolidation was achieved in 75% of patients, with an overall healing rate of 91.7% after secondary interventions. Recurrence occurred in 16.7% of cases and was significantly associated with prior surgical treatment (p = 0.045). No significant correlation was found between cyst size and recurrence (p = 0.151). At final follow-up (median 8.5 months), all patients demonstrated complete healing according to the modified Neer classification following completion of treatment. Functional outcomes were favorable, with 91.7% of patients regaining full range of motion and no neurovascular complications observed. The presented single-stage approach combining SAE, intralesional resection, and structural allograft reconstruction addresses both the vascular supply and mechanical instability of proximal humerus ABCs. This strategy demonstrated high healing rates and favorable functional outcomes, with acceptable recurrence rates in this cohort while avoiding donor site morbidity. It represents a practical and effective treatment concept for this rare pediatric condition.
2026-03-14 | 3D-Planned, Patient-Specific Distal Radius Reconstruction with a Vascularized Double-Barrel Free Fibular Graft After Secondary Aneurysmal Bone Cyst.
Background/Objectives: An Aneurysmal Bone Cyst (ABC) is a rare benign osteolytic bone lesion with locally destroying growth. It occurs mostly in the first two decades of life, rarely in older patients, and commonly affects the metaphysis. Clinical presentation includes pain and pathologic fractures. While most ABCs occur as primary lesions, there is an entity of secondary (reactive) ABC following osseous lesions such as fractures. We report a rare case of a secondary aneurysmal bone cyst of the distal radius following a distal radius fracture 4 years prior, with subsequent treatment and reconstruction. Methods: A 67-year-old female patient presented with a pathologic distal forearm fracture with radiologically expansive lytic bone lesion of the metaphysis of the distal radius, suspicious of an ABC. A biopsy and primary fracture management with an external fixator were performed due to the unclear dignity of the lesion. The diagnosis of an ABC was confirmed in the biopsy. The tumor resection and reconstruction were performed with a vascularized free fibula graft (ipsilateral, double barrel), using patient-specific 3D-printed osteotomy templates. Results: Follow-up radiographs showed excellent bone union with progressive remodeling. The functional outcome was very good with almost the same range of motion and grip strength as the contralateral side. No limitation in everyday life and no donor site morbidity was reported. Conclusions: ABC is a rare benign bone tumor the treatment of which consists of complete resection and reconstruction. Reconstruction of the distal radius can be achieved with a fibula graft. In our case, an excellent result was achieved with patient-specific osteotomy templates. Only a few cases of ABC in the distal radius and at this age have been reported; nevertheless, it should be considered as a differential diagnosis for osteolytic bone lesions.
proteins
2026-05-31 | Primary Aneurysmal Bone Cyst of Long Bones Treated with a Single Dose of Calcitonin and Methylprednisolone Percutaneous Intralesional Injection: A Retrospective Observational Study
Background: Primary aneurysmal bone cyst (ABC) is a benign but locally aggressive osteolytic neoplasm, typically affecting children and young adults and commonly arising in the metaphysis of long bones. Conventional curettage remains widely used but may be associated with recurrence, physeal risk, fracture, donor-site morbidity, and need for reconstruction. Percutaneous intralesional injection using calcitonin and methylprednisolone offers a biologically plausible, low-morbidity alternative. Aim: To describe the clinical, radiological, functional, and safety outcomes of primary long-bone ABCs treated with a single percutaneous intralesional dose of calcitonin plus methylprednisolone, and to compare these findings with contemporary minimally invasive and surgical literature. Methods: A retrospective case series design was used. Patients with histopathologically confirmed primary ABC of a long bone, treated by image-guided intralesional calcitonin 200 IU plus methylprednisolone 120 mg, and followed clinically and radiologically were included. Outcomes included time to radiological healing, functional recovery using an MSTS-style percentage score, complications, recurrence, and need for additional treatment. Results: Six patients were analysed. Median age was 15.5 years, three were female, and lesions involved the tibia, femur, humerus, and radius. All lesions achieved radiological healing without open surgery. Mean time to healing was 2.83 months, mean final functional score was 89.0%, and no recurrence was observed during a mean follow-up of 28 months. One patient reported transient post-injection pain; no infection, neurovascular injury, systemic steroid event, or procedure-related fracture was recorded. Conclusion: In this small, long-bone case series, a single percutaneous injection of calcitonin and methylprednisolone was associated with rapid radiological consolidation, good functional recovery, and low morbidity. The technique appears suitable for selected primary ABCs where structural stability is preserved, but larger prospective multicentre studies are needed.
2025-06-28 | Treatment of Recurrent Aneurysmal Bone Cyst in a Dog Using Bone Morphogenetic Protein-2-loaded Alginate Microbeads.
Aneurysmal bone cysts (ABCs) are benign osteolytic lesions associated with lameness and present therapeutic challenges due to their frequent recurrence following surgery. This case report describes the surgical management and long-term outcomes of recurrent femoral ABC in a dog treated with multiple adjuvant therapies, including bone morphogenetic protein-2 (BMP-2)-loaded alginate microbeads. A 2-year-old neutered male Golden Retriever presented with right hindlimb lameness. Three months before, the dog underwent initial surgical curettage and bone grafting of a femoral lesion, confirmed as ABC by histopathology. Radiographs revealed an osteolytic lesion in the right distal femur with resorption of previously applied bone grafts. Revision surgery involved curettage and a high-speed burring, followed by filling the defect with cancellous bone autografts, bone marrow, BMP-2-loaded alginate microbeads, and BMP-2-soaked cancellous bone allograft chips. The dog restored normal gait within two months postoperatively. Follow-up radiographs indicated progressive bone formation without recurrence. The dog remained asymptomatic 29 months after the revision surgery. The combined use of a high-speed burr, BMP-2-loaded alginate microbeads, and bone graft materials resulted in favorable clinical outcomes in recurrent ABC, without recurrence up to 29 months postoperatively.
2024-12-19 | Limb salvage in Christmas disease masquerading as fungating aneurysmal bone cyst.
A boy in middle childhood presented with complaints of swelling and pain in his right forearm for 4 months. He had previously undergone left above-elbow amputation due to a suspected malignant tumour in that arm. Radiological imaging revealed a locally aggressive bone tumour of the right distal radius. Two biopsies failed to provide a diagnosis, and in the meantime the lesion became fungating. Consequently, it was decided to perform wide resection together with wrist arthrodesis. Postoperatively, on day 4, the patient developed wound dehiscence and impending compartment syndrome. During revision surgery, a significant quantity of blood clots was removed, without any active bleeders. Due to the uncertain diagnosis, thromboelastography (TEG) analysis was done, which showed a fibrinolytic pattern, and the patient's factor IX level was found to be 4% of the normal value. As a result, a diagnosis of haemophilia B was established. The patient was started on tranexamic acid and factor IX replacement therapy.
2021-11-18 | Aneurysmal bone cyst and osteoblastoma: an extremely rare combination in the pediatric spine.
Case report. To report the clinical and imaging findings of a patient with the extremely rare association of aneurysmal bone cyst and osteoblastoma in the cervical spine. To our knowledge, only three cases have been reported in the published literature in children under 16 years of age with this condition in the cervical spine. The patient's history, physical examination, imaging findings, and management with a complete 4-year medical history, surgical intervention and radiological follow-up are reported. A 4-year 11-month-old boy was diagnosed with aneurysmal bone cyst in association of osteoblastoma and was treated with CT-guided intralesional injection calcitonin and methylprednisolone. During the course of intralesional therapy, a pathological fracture of C2 was produced. Subsequently, a widened intralesional excision and instrumented fusion from occiput to cervical spine (C0-C4) was performed. The association of aneurysmal bone cyst and osteoblastoma in spine is extremely rare. Although both are benign lesions, in the cervical location, complete removal of the tumors is challenging. Wide resection with reconstruction of the segments for stability associated with adjuvant treatment with calcitonin and corticosteroids provides a good option.
2019-04-03 | An aneurysmal bone cyst at T1 treated with bone grafts containing calcitonin and methylprednisolone
Aneurysmal bone cysts (ABCs) rarely trigger pathological fractures. Various surgical and nonsurgical treatments have been reported for this condition. Herein, we present the examination findings and treatment for a 15-year-old girl who initially presented with adolescent idiopathic scoliosis and mild back pain, but subsequently experienced severe back pain. Magnetic resonance imaging revealed an ABC at T1, with an associated pathological fracture. We successfully treated the patient using posterior fixation with instrumentation, curettage, and bone grafts combined with calcitonin and methylprednisolone (mPSL). At 3 years post-surgery, there was no ABC recurrence and only mild back pain persisted. To our knowledge, this is the first report of open surgery (curettage and fixation) with local intralesional administration of calcitonin and mPSL for an ABC-induced pathological spinal fracture. We believe that this treatment is an effective option for ABCs associated with a pathological spinal fracture.
antibodies
2026-08-17 | Primary denosumab therapy for a three-column pediatric cervical aneurysmal bone cyst: illustrative case.
Pediatric spinal aneurysmal bone cysts (ABCs) involving all three columns present significant surgical challenges due to high procedural morbidity and vertebral artery risks. While denosumab is utilized off-label for these aggressive lesions, its efficacy and safety in pediatric spinal cases remain insufficiently characterized. A 12-year-old girl with a C6 ABC and progressive myelopathy (modified Japanese Orthopaedic Association [mJOA] score 14) underwent 12 months of primary denosumab therapy. Neurological recovery was rapid, with the mJOA score improving to 17 by the 2nd month. Serial imaging confirmed centripetal ossification and indirect cord decompression, while sagittal alignment remained stable. A structured review of 33 pediatric spinal ABC cases supported the role of denosumab in achieving early clinical and radiographic stabilization. Denosumab serves as a viable alternative for aggressive pediatric spinal ABCs when surgical morbidity is prohibitive. However, clinicians must monitor for severe rebound hypercalcemia following treatment cessation and potential late recurrence. Long-term surveillance is mandatory to ensure metabolic safety and evaluate the durability of the ossified bone matrix. https://thejns.org/doi/10.3171/CASE26396.
2026-07-03 | The treatment of paediatric bone cysts
This thesis covers research into the treatment of the three most common types of paediatric bone cysts in Children: simple bone cysts, aneurysmal bone cysts en fibrous dysplasia. |
2026-04-09 | The use of denosumab in rare bone diseases in adults: a systematic review from the ECTS Rare Bone Disease Action Group.
Rare bone diseases may display a disrupted RANKL-RANK-Osteoprotegerin pathway causing increased osteoclastogenesis and enhanced bone resorption. Although bisphosphonates are commonly used, they often fall short of desired outcomes. Denosumab, an anti-RANKL antibody, provides a promising alternative by swiftly and strongly suppressing bone turnover (faster and more potent suppression of bone resorption than bisphosphonates), though its effects are reversible upon discontinuation. The use of denosumab has been highlighted, especially in pediatric cases but not substantially in adults. A targeted evidence search was conducted to retrieve studies reporting denosumab use in rare bone diseases in adults. Denosumab administration may lead to pain reduction, lesion reduction or bone formation. Treatment dosage, schedules and duration varied, however, a dose of 120 mg dosed monthly or 3 monthly for almost one year reached the desired treatment effect in most patients. Denosumab is generally well tolerated in adults, with mild common side effects such as (asymptomatic) hypocalcemia and hypophosphatemia. Serious adverse effects such as osteonecrosis of the jaw or atypical femoral fractures are rarely reported. Main concerns regard rebound effect after denosumab discontinuation, with disease recurrence in some cases. Zoledronic acid after discontinuation of denosumab might be advisable, but is seldom reported. Denosumab is a feasible treatment in adults with rare bone diseases when managed by multidisciplinary teams with knowledge of both the underlying disease and potential surgeries as well as the medical site of treatment. Denosumab discontinuation management is paramount to prevent recurrence and severe complications. The paucity of data supports the need for data collection through rare disease registries for future pertinent evidence-based recommendations.
2026-02-27 | Recurrent aneurysmal bone cyst of the spine in a pediatric medulloblastoma survivor: Successful treatment with denosumab
Background: Aneurysmal bone cysts (ABCs) are rare, benign, but potentially aggressive bone lesions, particularly challenging when located in the spine. Recurrent ABCs in pediatric patients present significant therapeutic dilemmas, especially after incomplete surgical resections. Case Description: We report the case of a 6-year-old girl, previously treated for medulloblastoma, who developed a recurrent spinal ABC at the L1 vertebral level. Despite undergoing two incomplete resections due to the lesion’s location and involvement of critical structures, recurrence was observed. Given the elevated surgical risk and tumor persistence, off-label denosumab therapy was initiated. After 12 months of monthly administration, the patient demonstrated clinical improvement, radiological stability, and no reported adverse effects. Conclusion: This case highlights the potential role of denosumab as an adjuvant treatment option for recurrent spinal ABCs when complete surgical resection is not feasible. While promising, further studies are warranted to define optimal dosing, treatment duration, and long-term safety in pediatric patients.
2026-02-16 | ANEURYSMAL BONE CYST: A CASE SERIES OF AN AGGRESSIVE BENIGN TUMOR.
The Aneurysmal Bone Cyst (ABC) is a benign yet aggressive bone tumor. This study aimed to evaluate sex, age, tumor location, tumor size, type of treatment (surgical, infiltration, embolization), and recurrence. Descriptive and quantitative statistical analyses were applied. The prevalence ratio and 95% confidence interval were calculated for the association between recurrence and sex, age, tumor size, Capanna's classification, and treatment type. Twenty-three cases of ABCs were included, eleven (47.8%) females and twelve (52.2%) males. The mean age of treated patients was 11.2±1.8 years. Most cysts were located in the lower limbs (56.5%). The mean follow-up time was 42.8±14.01 months. The mean cyst diameter at the beginning of treatment was 5.58± 1.04 cm; of these, 17.4% were up to 3 cm, 43.5% from 3.1 to 6 cm, and 39.1% over 6 cm. Regarding initial treatment, 6 (26%) patients received infiltration, and in total 20 (86.9%) underwent surgery with bone grafting. The overall recurrence rate was 30.4%. No association was identified between recurrence and the variables studied (p ≥ 0.05). The epidemiological data obtained are consistent with pediatric cohorts reported in the literature. All evaluated methods are suitable for treating aneurysmal bone cysts. Level of Evidence IV; Case Series.
small molecules
2026-07-22 | Polidocanol Sclerotherapy Plus Adjuvant Autogenous Bone Marrow Injection for Management of Aneurysmal Bone Cyst: A Prospective Study.
Aneurysmal bone cysts (ABCs) are benign bone lesions that exhibit localized destructive growth. Conventionally, most patients are treated with curettage and bone grafting. Alternatively, percutaneous treatment using selective arterial embolization and sclerotherapy had been successfully used with promising results. Adjuvant use of bone marrow injection alone or with other agents for treatment of bone cysts was previously used. The aim of this work is to assess the clinical outcome of polidocanol sclerotherapy with adjuvant autogenous bone marrow injection for management of ABCs. The present prospective study was conducted on 20 patients with ABCs diagnosed on the basis of clinical and radiological findings. All patients were managed using polidocanol sclerotherapy followed by adjuvant autogenous bone marrow injection. Pain was evaluated using Visual Analog Scale (VAS). Radiographic evaluation was performed using plain radiographs. All patients were followed for 30 months after the last treatment session. The present study was conducted on 20 patients with an age of 10.2 ± 4.4 years (range: 3.0-20.0 years). They comprised 12 males and 8 females. VAS for pain improved from 6.2 ± 1.4 at baseline to 0.3 ± 0.5 (p < 0.001) at the end of follow-up. Radiologically, cyst volume significantly decreased from 79.9 ± 26.3 ml to 2.0 ± 2.1 ml (p < 0.001). Reported complications included recurrence (5.0%), ecchymosis (10.0%), and nausea and vomiting (5.0%). Use of polidocanol sclerotherapy followed by adjuvant autogenous bone marrow injection for management of ABCs is highly effective with adequate safety profile.
2026-07-16 | Aneurysmal bone cyst of the calcaneus: a case report and review of the literature.
Aneurysmal bone cysts (ABCs) are locally destructive, blood-filled benign bone lesions traditionally regarded as reactive rather than true neoplastic lesions. ABCs typically affect the proximal humerus, distal femur, proximal tibia, and spine. Involvement of the calcaneus is rare, representing approximately 1.6% of reported cases. A PubMed search identified nine publications describing 22 cases of calcaneal ABCs. Here, we report a rare case of ABC arising in the calcaneus and review the relevant literature. A 17-year-old Japanese male with no relevant medical history presented with left calcaneal pain and gait disturbance. The patient underwent curettage with phenol-ethanol ablation and artificial bone packing (β-tricalcium phosphate [β-TCP], AFFINOS®, KURARAY Co., Tokyo, Japan). No local tumor recurrence was observed at the 36-month follow-up. This case highlights a rare ABC arising in the left calcaneus of a 17-year-old Japanese male, with no recurrence after 36 months. Although adjuvant therapy was performed in this case, additional cases are required to clarify its necessity in the management of calcaneal ABC.
2026-07-13 | Percutaneous Sclerotherapy of Diaphyseal Aneurysmal Bone Cyst of Tibia in a Child
Abstract Aneurysmal bone cysts (ABCs), though benign, are locally aggressive. ABCs may cause symptoms such as painful limping and may lead to pathological fractures. Traditional surgical methods of treatment have an increased risk of recurrence, morbidity, and longer hospital stays. While selective arterial embolization can be performed, it may not be feasible in resource-limited conditions. Percutaneous image-guided sclerotherapy of the ABCs can be an effective treatment option. This case report describes a minimally invasive technique for percutaneous sclerotherapy of a tibial diaphyseal aneurysmal bone cyst using a combination of polidocanol and gelatin sponge slurry as a cost-effective and minimally invasive method.
2026-07-09 | Aneurysmal Bone Cyst of the Distal Tibia Treated by Intralesional Curettage and Cementation: A Case Report
Introduction: Aneurysmal bone cyst (ABC) is a benign but locally aggressive osteolytic bone neoplasm characterised by blood-filled, multi-septated cavities. It predominantly affects the metaphyseal regions of long bones in children and young adults. Distal tibial involvement is uncommon and presents specific surgical challenges due to the proximity of the ankle joint and physis. We report a case of a large ABC of the distal tibia treated successfully with intralesional curettage and polymethylmethacrylate (PMMA) cementation. Case Presentation: A 30-year-old patient presented with progressive pain and swelling of the right ankle. Plain radiographs and computed tomography (CT) revealed a large, expansile, multi-lobulated metaphyso-epiphyseal osteolytic lesion of the distal tibia measuring 40 × 26 mm in cross-section with a 38 mm craniocaudal extent, cortical thinning, and no soft tissue invasion. Magnetic resonance imaging (MRI) demonstrated pathognomonic fluid-fluid levels on T2-weighted sequences with moderate peripheral gadolinium enhancement, consistent with ABC. Intralesional curettage and PMMA cementation were performed. Histopathological examination confirmed the diagnosis. At final follow-up, the patient achieved complete resolution of pain and full, pain-free ankle range of motion with no recurrence. Conclusion: ABC of the distal tibia is a rare but treatable periarticular lesion. MRI with fluid-fluid levels is the cornerstone of preoperative characterisation. Intralesional curettage combined with PMMA cementation offers immediate mechanical stability, facilitates recurrence surveillance, and yields excellent functional outcomes.
2026-07-06 | Intracranial aneurysmal bone cysts in association with fibrous dysplasia: Case report and scoping review of case reports.
Aneurysmal bone cyst (ABC) in association with craniofacial fibrous dysplasia (FD) is rare and may mimic aggressive change when a previously indolent lesion enlarges rapidly. We report an intracranial/cranial vault case and map published cranial vault/skull-base cases. A 16-year-old girl presented with a rapidly enlarging left parietal mass, headache, intermittent diplopia, and vertigo. Magnetic resonance imaging demonstrated expansive craniofacial/skull-base FD with a multiloculated osteolytic parietal component containing hemorrhagic fluid-fluid levels, suggestive of ABC. Preoperative embolization was followed by resection and cranial reconstruction. Histopathology confirmed FD with a focal ABC component. At 3-year follow-up, the patient had no recurrence of the resected lesion. A scoping review was performed using structured PubMed/MEDLINE and Embase searches from database inception to December 2025, limited to articles in English or Spanish, including case reports/series of ABC in association with FD involving the cranial vault and/or skull base. Thirty-three individual cases were identified: 57.6% male, mean age 18.6 years (range 6-40). FD was polyostotic in 48.5%, monostotic in 24.2%, and unspecified in 27.3%. The frontal bone was the most frequent site (15.2%). The cystic ABC pattern predominated (75.8%). Follow-up was reported in 54.5% (mean 9.6 months among reported cases). ABC should be considered when craniofacial FD shows rapid enlargement, pain, neurological/neuro-ophthalmologic symptoms, or fluid-fluid levels. Diagnosis requires clinicoradiologic-pathologic correlation. Management should be individualized, often favoring embolization and maximal safe resection with reconstruction and long-term surveillance.
cell therapies
2026-07-21 | Minimally Invasive Treatment of Aneurysmal Bone Cysts Utilizing a Modified Sclerograft Technique.
Aneurysmal bone cysts (ABCs) are locally aggressive expansile bone tumors that typically present near the metaphysis and are commonly encountered in the pediatric population. This study presents the results of a single staged procedure, which is a modification of the Sclerograft procedure (chemical sclerotherapy combined with regenerative bone grafting) used to treat unicameral bone cysts (UBCs), as an alternative treatment paradigm. This retrospective, single-institution study included patients with MRI-confirmed primary aneurysmal bone cysts of the appendicular skeleton treated between 2020 and 2025. Eligible patients underwent mechanical disruption with doxycycline sclerotherapy (± cryoablation) and regenerative bone grafting. Demographics, lesion characteristics, prior treatments, imaging, and clinical outcomes were analyzed. The final cohort included 27 patients (15 females, 12 males) with a mean age of 10.6 years. The primary outcome was the reintervention rate. Patients underwent a median of 1 procedure (range 1-3; mean 1.33) over a median follow-up of 1.88 years (range 0.5-5.8 years). 7 of 27 (25.9%) required at least one additional procedure due to radiographic (Modified Neer Grade 3-4) and symptomatic recurrence. Median time to retreatment was 12.2 months (IQR 6.8-19.4). Radiographs were the primary follow-up imaging modality (92.6%). The modified Sclerograft technique is a feasible, single-session treatment option for primary aneurysmal bone cysts with promising results that warrant further study as a possible alternative to the historical paradigm of serial sclerotherapy. Utilizing regenerative bone graft facilitates bone formation and permits the majority of follow-up to be performed with plain radiographs.
2026-07-10 | Aneurysmal Bone Cyst of the Proximal Humerus Managed with En Bloc Resection, Fibular Strut Grafting, and PHILOS Fixation: A Case Report.
Aneurysmal bone cyst (ABC) is a benign, locally aggressive osteolytic lesion characterized by expansile blood-filled cavities separated by fibrous septa affecting the metaphyseal region of long bones in young individuals and accounting for approximately 1-2% of primary bone tumors. Proximal humerus involvement presents with reconstructive challenges due to the need to preserve shoulder biomechanics and rotator cuff function. A 28-year-old female presented with progressive pain and swelling of the left shoulder for 5 months, with restricted overhead activity. Imaging showed an expansile metaphyseal lytic lesion (Capanna Type II). A prior biopsy was suggestive of ABC. Two trials of selective arterial embolization failed to improve clinically and radiologically. Management included repeat pre-operative angio-embolization followed by en bloc resection. The defect was reconstructed using a 15-cm non-vascularized ipsilateral fibular strut graft stabilized with a PHILOS plate. Histopathology confirmed the diagnosis of ABC. Serial follow-up demonstrated graft incorporation and union with restoration of painless full shoulder motion. Large proximal humerus ABCs require meticulous oncologic clearance combined with stable structural reconstruction. Pre-operative embolization followed by en bloc excision, fibular strut grafting, and PHILOS fixation provides satisfactory functional and radiological outcomes.
2026-07-10 | Aneurysmal Bone Cyst of Calcaneum in a Young Adult: A Rare Case Report.
Aneurysmal bone cyst (ABC) is a benign but locally aggressive osteolytic lesion that commonly affects long bones and vertebrae. Involvement of the calcaneum is rare and presents a unique diagnostic and therapeutic challenge due to its weight-bearing nature. A 23-year-old male presented with pain in the left heel for 6 months, insidious in onset and progressive in nature, aggravated by weight bearing. Clinical examination revealed localized tenderness over the calcaneum. Radiographs showed an expansile osteolytic lesion with cortical thinning. Magnetic resonance imaging demonstrated a multiloculated cystic lesion with multiple fluid-fluid levels suggestive of ABC. The patient underwent extended curettage and autologous cancellous bone grafting and bone substitute. Histopathological examination confirmed the diagnosis of ABC. At 6 months follow-up, the patient was asymptomatic with no evidence of recurrence. Calcaneal ABC is a rare entity that should be considered in young patients presenting with chronic heel pain. Imaging aids in diagnosis, but histopathology is mandated. Extended curettage with bone grafting is an effective treatment option with good functional outcomes and low recurrence rates.
2026-05-27 | Single-Stage Combined Embolization and Structural Allograft Reconstruction for Proximal Humerus Aneurysmal Bone Cysts in Children.
Aneurysmal bone cysts (ABCs) of the proximal humerus in children are rare, locally aggressive lesions associated with substantial recurrence rates and risk of structural instability. Conventional treatment by curettage and bone grafting is often limited by recurrence, while selective arterial embolization (SAE) alone may not provide sufficient structural support. This study evaluates a single-stage treatment strategy combining embolization and structural reconstruction to address both the vascular and mechanical components of the disease. A retrospective analysis was performed on 12 pediatric patients (median age 9 years) with proximal humerus ABCs treated between 2020 and 2024. All patients underwent a standardized single-stage protocol consisting of preoperative SAE, intralesional resection with high-speed burr, and reconstruction using an allogeneic fibula graft combined with cancellous bone augmentation. Radiological consolidation, recurrence, and functional outcomes were assessed. Associations between prior surgery, cyst size, and recurrence were analyzed. Primary consolidation was achieved in 75% of patients, with an overall healing rate of 91.7% after secondary interventions. Recurrence occurred in 16.7% of cases and was significantly associated with prior surgical treatment (p = 0.045). No significant correlation was found between cyst size and recurrence (p = 0.151). At final follow-up (median 8.5 months), all patients demonstrated complete healing according to the modified Neer classification following completion of treatment. Functional outcomes were favorable, with 91.7% of patients regaining full range of motion and no neurovascular complications observed. The presented single-stage approach combining SAE, intralesional resection, and structural allograft reconstruction addresses both the vascular supply and mechanical instability of proximal humerus ABCs. This strategy demonstrated high healing rates and favorable functional outcomes, with acceptable recurrence rates in this cohort while avoiding donor site morbidity. It represents a practical and effective treatment concept for this rare pediatric condition.
2026-03-14 | 3D-Planned, Patient-Specific Distal Radius Reconstruction with a Vascularized Double-Barrel Free Fibular Graft After Secondary Aneurysmal Bone Cyst.
Background/Objectives: An Aneurysmal Bone Cyst (ABC) is a rare benign osteolytic bone lesion with locally destroying growth. It occurs mostly in the first two decades of life, rarely in older patients, and commonly affects the metaphysis. Clinical presentation includes pain and pathologic fractures. While most ABCs occur as primary lesions, there is an entity of secondary (reactive) ABC following osseous lesions such as fractures. We report a rare case of a secondary aneurysmal bone cyst of the distal radius following a distal radius fracture 4 years prior, with subsequent treatment and reconstruction. Methods: A 67-year-old female patient presented with a pathologic distal forearm fracture with radiologically expansive lytic bone lesion of the metaphysis of the distal radius, suspicious of an ABC. A biopsy and primary fracture management with an external fixator were performed due to the unclear dignity of the lesion. The diagnosis of an ABC was confirmed in the biopsy. The tumor resection and reconstruction were performed with a vascularized free fibula graft (ipsilateral, double barrel), using patient-specific 3D-printed osteotomy templates. Results: Follow-up radiographs showed excellent bone union with progressive remodeling. The functional outcome was very good with almost the same range of motion and grip strength as the contralateral side. No limitation in everyday life and no donor site morbidity was reported. Conclusions: ABC is a rare benign bone tumor the treatment of which consists of complete resection and reconstruction. Reconstruction of the distal radius can be achieved with a fibula graft. In our case, an excellent result was achieved with patient-specific osteotomy templates. Only a few cases of ABC in the distal radius and at this age have been reported; nevertheless, it should be considered as a differential diagnosis for osteolytic bone lesions.
proteins
2026-05-31 | Primary Aneurysmal Bone Cyst of Long Bones Treated with a Single Dose of Calcitonin and Methylprednisolone Percutaneous Intralesional Injection: A Retrospective Observational Study
Background: Primary aneurysmal bone cyst (ABC) is a benign but locally aggressive osteolytic neoplasm, typically affecting children and young adults and commonly arising in the metaphysis of long bones. Conventional curettage remains widely used but may be associated with recurrence, physeal risk, fracture, donor-site morbidity, and need for reconstruction. Percutaneous intralesional injection using calcitonin and methylprednisolone offers a biologically plausible, low-morbidity alternative. Aim: To describe the clinical, radiological, functional, and safety outcomes of primary long-bone ABCs treated with a single percutaneous intralesional dose of calcitonin plus methylprednisolone, and to compare these findings with contemporary minimally invasive and surgical literature. Methods: A retrospective case series design was used. Patients with histopathologically confirmed primary ABC of a long bone, treated by image-guided intralesional calcitonin 200 IU plus methylprednisolone 120 mg, and followed clinically and radiologically were included. Outcomes included time to radiological healing, functional recovery using an MSTS-style percentage score, complications, recurrence, and need for additional treatment. Results: Six patients were analysed. Median age was 15.5 years, three were female, and lesions involved the tibia, femur, humerus, and radius. All lesions achieved radiological healing without open surgery. Mean time to healing was 2.83 months, mean final functional score was 89.0%, and no recurrence was observed during a mean follow-up of 28 months. One patient reported transient post-injection pain; no infection, neurovascular injury, systemic steroid event, or procedure-related fracture was recorded. Conclusion: In this small, long-bone case series, a single percutaneous injection of calcitonin and methylprednisolone was associated with rapid radiological consolidation, good functional recovery, and low morbidity. The technique appears suitable for selected primary ABCs where structural stability is preserved, but larger prospective multicentre studies are needed.
2025-06-28 | Treatment of Recurrent Aneurysmal Bone Cyst in a Dog Using Bone Morphogenetic Protein-2-loaded Alginate Microbeads.
Aneurysmal bone cysts (ABCs) are benign osteolytic lesions associated with lameness and present therapeutic challenges due to their frequent recurrence following surgery. This case report describes the surgical management and long-term outcomes of recurrent femoral ABC in a dog treated with multiple adjuvant therapies, including bone morphogenetic protein-2 (BMP-2)-loaded alginate microbeads. A 2-year-old neutered male Golden Retriever presented with right hindlimb lameness. Three months before, the dog underwent initial surgical curettage and bone grafting of a femoral lesion, confirmed as ABC by histopathology. Radiographs revealed an osteolytic lesion in the right distal femur with resorption of previously applied bone grafts. Revision surgery involved curettage and a high-speed burring, followed by filling the defect with cancellous bone autografts, bone marrow, BMP-2-loaded alginate microbeads, and BMP-2-soaked cancellous bone allograft chips. The dog restored normal gait within two months postoperatively. Follow-up radiographs indicated progressive bone formation without recurrence. The dog remained asymptomatic 29 months after the revision surgery. The combined use of a high-speed burr, BMP-2-loaded alginate microbeads, and bone graft materials resulted in favorable clinical outcomes in recurrent ABC, without recurrence up to 29 months postoperatively.
2024-12-19 | Limb salvage in Christmas disease masquerading as fungating aneurysmal bone cyst.
A boy in middle childhood presented with complaints of swelling and pain in his right forearm for 4 months. He had previously undergone left above-elbow amputation due to a suspected malignant tumour in that arm. Radiological imaging revealed a locally aggressive bone tumour of the right distal radius. Two biopsies failed to provide a diagnosis, and in the meantime the lesion became fungating. Consequently, it was decided to perform wide resection together with wrist arthrodesis. Postoperatively, on day 4, the patient developed wound dehiscence and impending compartment syndrome. During revision surgery, a significant quantity of blood clots was removed, without any active bleeders. Due to the uncertain diagnosis, thromboelastography (TEG) analysis was done, which showed a fibrinolytic pattern, and the patient's factor IX level was found to be 4% of the normal value. As a result, a diagnosis of haemophilia B was established. The patient was started on tranexamic acid and factor IX replacement therapy.
2021-11-18 | Aneurysmal bone cyst and osteoblastoma: an extremely rare combination in the pediatric spine.
Case report. To report the clinical and imaging findings of a patient with the extremely rare association of aneurysmal bone cyst and osteoblastoma in the cervical spine. To our knowledge, only three cases have been reported in the published literature in children under 16 years of age with this condition in the cervical spine. The patient's history, physical examination, imaging findings, and management with a complete 4-year medical history, surgical intervention and radiological follow-up are reported. A 4-year 11-month-old boy was diagnosed with aneurysmal bone cyst in association of osteoblastoma and was treated with CT-guided intralesional injection calcitonin and methylprednisolone. During the course of intralesional therapy, a pathological fracture of C2 was produced. Subsequently, a widened intralesional excision and instrumented fusion from occiput to cervical spine (C0-C4) was performed. The association of aneurysmal bone cyst and osteoblastoma in spine is extremely rare. Although both are benign lesions, in the cervical location, complete removal of the tumors is challenging. Wide resection with reconstruction of the segments for stability associated with adjuvant treatment with calcitonin and corticosteroids provides a good option.
2019-04-03 | An aneurysmal bone cyst at T1 treated with bone grafts containing calcitonin and methylprednisolone
Aneurysmal bone cysts (ABCs) rarely trigger pathological fractures. Various surgical and nonsurgical treatments have been reported for this condition. Herein, we present the examination findings and treatment for a 15-year-old girl who initially presented with adolescent idiopathic scoliosis and mild back pain, but subsequently experienced severe back pain. Magnetic resonance imaging revealed an ABC at T1, with an associated pathological fracture. We successfully treated the patient using posterior fixation with instrumentation, curettage, and bone grafts combined with calcitonin and methylprednisolone (mPSL). At 3 years post-surgery, there was no ABC recurrence and only mild back pain persisted. To our knowledge, this is the first report of open surgery (curettage and fixation) with local intralesional administration of calcitonin and mPSL for an ABC-induced pathological spinal fracture. We believe that this treatment is an effective option for ABCs associated with a pathological spinal fracture.
antibodies
2026-08-17 | Primary denosumab therapy for a three-column pediatric cervical aneurysmal bone cyst: illustrative case.
Pediatric spinal aneurysmal bone cysts (ABCs) involving all three columns present significant surgical challenges due to high procedural morbidity and vertebral artery risks. While denosumab is utilized off-label for these aggressive lesions, its efficacy and safety in pediatric spinal cases remain insufficiently characterized. A 12-year-old girl with a C6 ABC and progressive myelopathy (modified Japanese Orthopaedic Association [mJOA] score 14) underwent 12 months of primary denosumab therapy. Neurological recovery was rapid, with the mJOA score improving to 17 by the 2nd month. Serial imaging confirmed centripetal ossification and indirect cord decompression, while sagittal alignment remained stable. A structured review of 33 pediatric spinal ABC cases supported the role of denosumab in achieving early clinical and radiographic stabilization. Denosumab serves as a viable alternative for aggressive pediatric spinal ABCs when surgical morbidity is prohibitive. However, clinicians must monitor for severe rebound hypercalcemia following treatment cessation and potential late recurrence. Long-term surveillance is mandatory to ensure metabolic safety and evaluate the durability of the ossified bone matrix. https://thejns.org/doi/10.3171/CASE26396.
2026-07-03 | The treatment of paediatric bone cysts
This thesis covers research into the treatment of the three most common types of paediatric bone cysts in Children: simple bone cysts, aneurysmal bone cysts en fibrous dysplasia. |
2026-04-09 | The use of denosumab in rare bone diseases in adults: a systematic review from the ECTS Rare Bone Disease Action Group.
Rare bone diseases may display a disrupted RANKL-RANK-Osteoprotegerin pathway causing increased osteoclastogenesis and enhanced bone resorption. Although bisphosphonates are commonly used, they often fall short of desired outcomes. Denosumab, an anti-RANKL antibody, provides a promising alternative by swiftly and strongly suppressing bone turnover (faster and more potent suppression of bone resorption than bisphosphonates), though its effects are reversible upon discontinuation. The use of denosumab has been highlighted, especially in pediatric cases but not substantially in adults. A targeted evidence search was conducted to retrieve studies reporting denosumab use in rare bone diseases in adults. Denosumab administration may lead to pain reduction, lesion reduction or bone formation. Treatment dosage, schedules and duration varied, however, a dose of 120 mg dosed monthly or 3 monthly for almost one year reached the desired treatment effect in most patients. Denosumab is generally well tolerated in adults, with mild common side effects such as (asymptomatic) hypocalcemia and hypophosphatemia. Serious adverse effects such as osteonecrosis of the jaw or atypical femoral fractures are rarely reported. Main concerns regard rebound effect after denosumab discontinuation, with disease recurrence in some cases. Zoledronic acid after discontinuation of denosumab might be advisable, but is seldom reported. Denosumab is a feasible treatment in adults with rare bone diseases when managed by multidisciplinary teams with knowledge of both the underlying disease and potential surgeries as well as the medical site of treatment. Denosumab discontinuation management is paramount to prevent recurrence and severe complications. The paucity of data supports the need for data collection through rare disease registries for future pertinent evidence-based recommendations.
2026-02-27 | Recurrent aneurysmal bone cyst of the spine in a pediatric medulloblastoma survivor: Successful treatment with denosumab
Background: Aneurysmal bone cysts (ABCs) are rare, benign, but potentially aggressive bone lesions, particularly challenging when located in the spine. Recurrent ABCs in pediatric patients present significant therapeutic dilemmas, especially after incomplete surgical resections. Case Description: We report the case of a 6-year-old girl, previously treated for medulloblastoma, who developed a recurrent spinal ABC at the L1 vertebral level. Despite undergoing two incomplete resections due to the lesion’s location and involvement of critical structures, recurrence was observed. Given the elevated surgical risk and tumor persistence, off-label denosumab therapy was initiated. After 12 months of monthly administration, the patient demonstrated clinical improvement, radiological stability, and no reported adverse effects. Conclusion: This case highlights the potential role of denosumab as an adjuvant treatment option for recurrent spinal ABCs when complete surgical resection is not feasible. While promising, further studies are warranted to define optimal dosing, treatment duration, and long-term safety in pediatric patients.
2026-02-16 | ANEURYSMAL BONE CYST: A CASE SERIES OF AN AGGRESSIVE BENIGN TUMOR.
The Aneurysmal Bone Cyst (ABC) is a benign yet aggressive bone tumor. This study aimed to evaluate sex, age, tumor location, tumor size, type of treatment (surgical, infiltration, embolization), and recurrence. Descriptive and quantitative statistical analyses were applied. The prevalence ratio and 95% confidence interval were calculated for the association between recurrence and sex, age, tumor size, Capanna's classification, and treatment type. Twenty-three cases of ABCs were included, eleven (47.8%) females and twelve (52.2%) males. The mean age of treated patients was 11.2±1.8 years. Most cysts were located in the lower limbs (56.5%). The mean follow-up time was 42.8±14.01 months. The mean cyst diameter at the beginning of treatment was 5.58± 1.04 cm; of these, 17.4% were up to 3 cm, 43.5% from 3.1 to 6 cm, and 39.1% over 6 cm. Regarding initial treatment, 6 (26%) patients received infiltration, and in total 20 (86.9%) underwent surgery with bone grafting. The overall recurrence rate was 30.4%. No association was identified between recurrence and the variables studied (p ≥ 0.05). The epidemiological data obtained are consistent with pediatric cohorts reported in the literature. All evaluated methods are suitable for treating aneurysmal bone cysts. Level of Evidence IV; Case Series.
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