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

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

Treatment of Spinal Aneurysmal Bone Cyst with Percutaneous Injection of Hydroxyapatite Osteoconductive Cement.

PURPOSE: The aim of this study was to evaluate treatment efficacy of percutaneous injection of hydroxyapatite-osteoconductive-cement in patients with spinal aneurysmal bone cysts. MATERIALS AND METHODS: The study was designed as a retrospective observational clinical study. We included patients who were diagnosed with of spinal aneurysmal bone cyst, at our institution between 2013 and 2020, and treated with percutaneous injection of osteoconductive cement: "Cerament"® (BONESUPPORT AB, Lund, Sweden). Typical clinical and radiological features of the ABCs treatment and follow-up were investigated. RESULTS: Our study included nine patients, two children and seven adults. Three different types of approaches were applied: (single pedicle approach in 3 patients; double pedicle approach in 2 patients; while in the remaining cases, a multiple access approach was used. VAS score decreased from 8.5 ± 0.5 before treatment to 4.1 ± 0.9 at 6-months-follow up. All of the patients reacted well to treatment, with none neurological complications, complete loss of pain and achieved osteosclerosis as radiological marker of treatment success. CONCLUSION: Treatment of symptomatic spinal ABC's with hydroxyapatite cement is effective to achieve complete pain reduction and sclerosis.

The treatment of aneurysmal bone cysts.

PURPOSE OF REVIEW: Aneurysmal bone cysts are rare, locally aggressive bone tumors. Optimal treatment of ABCs is still matter of debate as therapies including sclerotherapy, selective arterial embolization and systemic treatment with denosumab are increasingly utilized, in addition to or instead of traditional curettage. The purpose of this review is to discuss current concepts and difficulties in diagnosing and treating primary ABCs, based on latest available literature. RECENT FINDINGS: In diagnostics, multiple new fusion partners of USP-6 have been described on next-generation sequencing specifically for primary ABCs. In a recent systematic review, failure rates of percutaneous injections and surgery were comparable. In a literature review, the use of denosumab seemed effective but resulted in multiple cases of severe hypercalcemia in children. SUMMARY: Accurately diagnosing primary ABC is crucial for treatment decisions. Curettage remains a valid treatment option, especially with adjuvant burring, autogenous bone grafting and phenolization. Percutaneous sclerotherapy represents a solid alternative to surgery, with polidocanol showing good results in larger studies. Systematic therapy with denosumab exhibits favorable results but should be reserved in the pediatric population for unresectable lesions, as it may result in severe hypercalcemia in children. When selecting a treatment option, localization, stability and safety should be considered.

Quistes óseos aneurismáticos. Terapia celular con células mononucleares y seguimiento imagenológico en dos pacientes adolescentes / Aneurysmal bone cysts. Mononuclear cell therapy and imaging follow-up in two adolescent patients

RESUMEN Los quistes óseos aneurismáticos son frecuentes en la edad pediátrica. Para su determinación se cuenta con diversos estudios imagenológicos como la radiografía y la tomografía axial computarizada que pueden colaborar al diagnóstico diferencial con otras lesiones. Existen disímiles opciones terapéuticas, el uso de factores de crecimiento autólogos se ha considerado como alternativa eficaz. Se presentan dos pacientes consultados en el servicio de Ortopedia del Hospital Provincial Pediátrico Universitario «José Luis Miranda¼, de Villa Clara, con diagnóstico clínico e imagenológico de quiste óseo aneurismático que recibieron tratamiento mediante terapia celular con células mononucleares con buena evolución clínica y radiográfica. Esta técnica es aplicable en nuestro medio ya que no requiere de estimables recursos materiales lo que constituye una fortaleza para su implementación. Las radiografías permiten reconocer la evolución posterior al tratamiento.

ABSTRACT Aneurysmal bone cysts are common in children. For its determination, various imaging studies are available, such as radiography and computerized axial tomography, which can collaborate in the differential diagnosis with other lesions. There are dissimilar therapeutic options, the use of autologous growth factors has been considered as an effective alternative. We present two patients seen in the Orthopedics service at "José Luis Miranda" University Pediatric Hospital in Villa Clara, with a clinical and imaging diagnosis of aneurysmal bone cyst who received treatment with mononuclear cell therapy having a good clinical and radiographic evolution. This technique is applicable in our environment since it does not require considerable material resources, which constitutes a strength for its implementation. X-rays allow us to recognize the evolution after treatment.

Update on aneurysmal bone cyst: pathophysiology, histology, imaging and treatment.

Aneurysmal bone cyst (ABC) is a benign but locally aggressive lesion that predominantly affects children and young adults. ABC, which accounts for approximately 70% of the cases, is now recognized to be a true neoplasm, whereas ABC-like changes associated to other bone neoplasms (also referred in the literature as secondary ABC) accounts for the remaining 30%. The solid variant of ABC is also considered a true neoplasm but is rare. ABC can involve any bone in the body, and although it has a metaphyseal preference, it can involve any part of a bone and soft tissues. As with any bone tumor, the initial evaluation of ABCs should be done with radiographs followed by magnetic resonance imaging or less frequently computed tomography for further characterization. The imaging appearance of ABC is variable; however, a lytic and expansile lesion with fluid-fluid levels is the most common presentation. The main differential diagnosis of an ABC in the pediatric population is unicameral bone cyst (UBC) and telangiectatic osteosarcoma, therefore a biopsy is recommended before treatment. The therapeutic options of ABC range from curettage with or without adjuncts such as phenol, liquid nitrogen, argon laser and bone grafting or bone substitutes to more recently employed alternatives such as image-guided sclerotherapy with various sclerosing agents and monoclonal antibodies (e.g., Denosumab).

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

BACKGROUND: Aneurysmal bone cysts (ABCs) are benign, locally aggressive neoplasms that typically affect patients during their first two decades of life. Curettage with or without bone grafting or adjuvants is the current standard treatment; however, other surgical and medical treatments, such as sclerotherapy, have been reported. Treatment options for cervical spine ABCs are more limited because the proximity of ABCs to critical structures leads to greater risk of spontaneous or treatment-related adverse events, including death. OBJECTIVE: To retrospectively review all children and young adults with cervical spine ABCs treated with doxycycline sclerotherapy at one referral center to assess its viability as a standalone treatment. MATERIALS AND METHODS: We retrospectively reviewed the clinical notes and imaging of 16 patients treated with doxycycline sclerotherapy for pathologically proven cervical spine ABCs at our institution between May 2008 and March 2021. All patients underwent image-guided percutaneous doxycycline sclerotherapy to ablate the ABC and stimulate bone formation. We assessed clinical outcomes through chart review and described post-treatment imaging outcomes using modified Neer scoring. RESULTS: Of the 16 total children and young adults treated, 2 were lost to follow-up, leaving 14 patients with a median age of 14.5 years. Twelve of these 14 patients were successfully treated with doxycycline sclerotherapy for a success rate of 86%. One patient experienced one treatment-related complication (Society of Interventional Radiology [SIR] adverse event classification D), before ultimately being successfully treated. Doxycycline treatment failed in two patients, who then underwent surgical management. Post-treatment imaging of successfully treated cases had a mean modified Neer score of 1.3, whereas post-treatment imaging in failed cases had a mean score of 3.5. CONCLUSION: Doxycycline sclerotherapy is a viable standalone treatment for cervical spine ABCs because it is safe and effective while avoiding the morbidity associated with open surgical treatments.

Quiste óseo aneurismático en el sacro: caso clínico y revisión de la literatura / Aneurysmal bone cyst in the sacrum: Case report and literature review

Los quistes óseos aneurismáticos son lesiones óseas benignas infrecuentes, de localización inusual en el sacro. Sintomatológicamente son inespecíficas. Tras un traumatismo aparece dolor, pudiendo acompañarse de complicaciones de estructuras adyacentes por edema asociado. Los hallazgos de las imágenes suelen ser característicos, aunque el diagnóstico debe confirmarse por biopsia y realizar diagnóstico diferencial con otros tumores. El tratamiento a aplicar en huesos largos consiste en legrado y relleno con material de reemplazo óseo. En el sacro pueden conllevar complicaciones neurológicas, siendo la embolización arterial selectiva una alternativa en su manejo. Describimos un caso de quistes óseos aneurismáticos en el sacro en un varón de 71 años con antecedente de leucemia linfoide crónica e hiperplasia benigna de próstata. El informe incluye la presentación clínica, los hallazgos de imagen y la evolución tras el tratamiento mediante embolización arterial selectiva. Este caso destaca las opciones terapéuticas y las dificultades encontradas en el manejo de estas lesiones en el sacro que complican su tratamiento habitual. La embolización arterial selectiva es una opción terapéutica en pacientes con quistes óseos aneurismáticos en el sacro, permitiendo tratamientos menos agresivos y prósperos resultados (AU)

Aneurysmal bone cysts are rare benign bone lesions. Location in the sacrum is unusual. Symptoms are nonspecific. After an injury, pain develops and complications of adjacent structures can be triggered by the associated oedema. Radiological presentation is usually characteristic but must be confirmed by biopsy and a differential diagnosis must be made with other tumours. Treatment in long bones is based in curettage and refill with bone replacement material. In the sacrum, neurological complications can develop with selective arterial embolisation being an alternative in their management. We describe the case of a 71-year-old male patient with sacral aneurysmal bone cysts and a history of chronic lymphoid leukaemia and benign prostatic hyperplasia. The report includes the clinical presentation, imaging findings and outcome after treatment with selective arterial embolisation. This case highlights the therapeutic options and difficulties encountered in the management of these lesions when located in the sacrum, which complicates their usual treatment. Selective arterial embolisation is a therapeutic option in patients with sacral aneurysmal bone cysts, allowing less aggressive treatments and favourable results (AU)

The role of percutaneous transarterial embolization in the management of spinal bone tumors: a literature review.

PURPOSE: Spinal bone tumors include a heterogeneous broad of primary or metastatic lesions that may present as incidental findings or manifest with painful symptoms and pathological fractures. Optimal management of spine bone lesions is often difficult and treatment algorithms are usually solidly based on surgery. We aimed to evaluate the contribution of trans-arterial embolization in this field, with particular attention to the procedure efficacy, technical difficulties and complications. METHODS: We present a literature review on the role of trans-arterial embolization in the management of spinal bone tumors, both primary and metastatic, evaluating its contribution as preoperative treatment, palliative procedure and standalone curative strategy. RESULTS: Trans-arterial embolization provides an important contribution to reducing surgery hemorrhagic risks, offering a better visualization of the operating field, and possibly increasing tumor susceptibility to chemotherapy or radiation therapy. Nonetheless, it plays an important part in pain palliation, with the unquestionable advantage of being easily repeatable in case of necessity. Its curative role as a standalone therapy is still subject of debate, and at the present time, satisfactory results have been recorded only in the treatment of aneurysmal bone cysts. CONCLUSION: Percutaneous trans-arterial embolization has established as a highly useful minimally invasive procedure in the management of spinal bone lesions, particularly as adjuvant preoperative therapy and palliative treatment.

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

PURPOSE: To evaluate the safety and effectiveness of combined transarterial embolization and percutaneous sclerotherapy in the treatment of refractory and nonresectable aneurysmal bone cysts (ABCs) as assessed by imaging and clinical outcomes. MATERIALS AND METHODS: This retrospective, single-center study included 16 consecutive patients (9 women and 7 men; median age, 17 years [range, 6-25 years]) who underwent combined transarterial embolization (using ethylene vinyl alcohol) and percutaneous sclerotherapy (using ethanol gel and polidocanol) for refractory and nonresectable ABCs. The median follow-up was 27.3 months (range, 6.7-47.5 months). Grade of mineralization (5-point Likert scale), grade of fluid-fluid levels (FFLs; 4-point Likert scale), and contrast-enhancing lesion volume were evaluated before and after treatment. The quality of life was determined before and after treatment using the Musculoskeletal Tumor Society (MSTS) score and the 36-Item Short Form Survey (SF-36) health questionnaire. RESULTS: A mean of 1.6 ± 0.7 transarterial embolizations and 3.2 ± 1.7 percutaneous sclerotherapies were performed. No adverse events were observed. All patients showed either partial or complete response; no patient showed ABC recurrence. The grade of mineralization (3.7 ± 0.7 after therapy vs 1.4 ± 0.5 at baseline; P < .0001) and grade of FFL (3.5 ± 0.8 after therapy vs 1.9 ± 0.6 at baseline; P < .0001) significantly improved after therapy compared with baseline. The mean contrast-enhancing lesion volume significantly decreased after treatment compared with baseline (45.9 mm³ ± 96.1 vs 156.0 mm³ ± 115.3, respectively; P = .0003). The MSTS scores (28.8 ± 1.8 after treatment vs 14.1 ± 8.6 at baseline; P < .0001) and SF-36 findings revealed a significant improvement in the quality of life after treatment compared with baseline, leaving most patients without relevant constraints. CONCLUSIONS: Combined transarterial embolization and percutaneous sclerotherapy is a minimally invasive, safe, and effective treatment option for refractory and nonresectable ABCs. Treatment fostered bone mineralization and significantly improved patients' quality of life.

Aneurysmal Bone Cysts of the Paranasal Sinuses: The Mayo Clinic Experience and Review of the Literature.

OBJECTIVE/HYPOTHESIS: Aneurysmal bone cysts (ABCs) are benign, lytic bone lesions, which rarely present in the paranasal sinuses. There is no published consensus on the appropriate diagnostic or treatment approach. Our objective was to elucidate the clinical behavior, treatment, and outcomes for patients with ABCs of the paranasal sinuses (psABCs). STUDY DESIGN: Retrospective case series and system review of the literature. METHODS: A retrospective chart review was performed to identify patients evaluated at the authors' institution with psABC and consolidated with literature reports of psABC. RESULTS: Eighty-nine patients met inclusion criteria. The most common presenting symptom was painless facial swelling (n = 35, 39%). The ethmoid sinuses were the most common site involved (n = 55, 62%). Surgical approach was reported in 74 cases including 20 endoscopic and 54 with an open or combined approach. Fifty-nine patients (71%) underwent gross total resection. Follow up data was reported for 67 patients. Fifteen patients (22%) were found to have recurrence or progression at follow up; 10/15 (66%) patients within the first 12 months, 14/15 (93%) within the first 24 months, and 1/15 (7%) greater than 24 months after treatment. Patients were more likely to have recurrence/progression if they presented with nasal discharge (P = .05), proptosis (P = .01), or orbital involvement (P = .03). CONCLUSIONS: psABCs typically present with painless swelling or nasal obstruction. Orbital involvement is a negative prognostic indicator with these patients more likely to have recurrence after treatment. Recurrence or progression of disease is most likely to occur within 2 years after treatment. Therefore, patients should be monitored closely during this time. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E2525-E2533, 2021.

Severe Acute Lung Injury After H2O2 Irrigation of an Aneurysmal Bone Cyst in an 8-Year-Old Girl: A Case Report.

An 8-year-old girl developed severe acute lung injury after irrigation of a pelvic aneurysmal bone cyst with H2O2 and filling with bone cement. Sudden profound oxygen desaturation occurred on the operating table when the patient was turned from the prone to the supine position. After a brief improvement in her oxygenation, the girl developed rapidly progressing severe respiratory failure necessitating reintubation and hour-long manual ventilation, while copious amounts of hemorrhagic frothy fluids were aspirated through the endotracheal tube. The patient started to improve after 24 hours and eventually made a full recovery. We hypothesize that the incident was caused by gas embolization and pulmonary endothelial damage by H2O2.

Percutaneous treatments of primary aneurysmal bone cysts: systematic review and meta-analysis.

PURPOSE: To systematically review the literature to determine recurrence rates of percutaneous treatments for primary aneurysmal bone cysts (ABC). METHODS: Search strategies were performed in the following databases: PubMed, SCIELO, LILACS and BVS, using terms in English, Spanish and Portuguese (PROSPERO Registration Number: CRD42020170340). Longitudinal studies, either observational or clinical trials, with at least five patients and with a mean of 18 months of follow-up were included. Studies had to use any type of percutaneous treatments and report the recurrence rates of primary ABC treatment. Studies selection, data extraction and risk of bias assessment were performed independently by two researchers. A global meta-analysis was carried out to assess the proportion of recurrence. Studies were categorized into two subgroups: selective arterial embolization and sclerotherapy. RESULTS: Thirteen studies were included in the present study. The average success rate of percutaneous treatments for ABC was 91.11%, with a total of 37 lesions recurrences in the 416 patients. The sex ratio was 1:1. The subgroup of sclerotherapies presented a lower proportion of recurrence. The proportion of recurrence in the subgroup of selective arterial embolization was 19% (95%IC 12.11-27.54) and that of sclerotherapies was 6% (95%IC 3.65-9.19). CONCLUSIONS: Both percutaneous treatments for ABC are effective, showing a lower rate of recurrence. Sclerotherapy treatments seem to be promising, but further clinical trials must be conducted with a longer follow-up.

[Andean children with aneurysmal bone cyst treated with polidocanol (use off-label)]. / Niños andinos con quiste óseo aneurismático tratados con polidocanol (uso fuera de etiqueta).

INTRODUCTION: The aneurysmal bone cyst is a rare benign but aggressive osteolytic tumor for which there is still no ideal treatment, the reports on treatment by sclerotherapy in the pediatric population are scarce and in our region even less. The objective is to communicate the experience of the treatment of aneurysmal bone cyst with polydocanol 3%. MATERIAL Y METHODS: Retrospective, descriptive and cross-sectional study. Period: June/2017 to June/2021. Inclusion: patients with histological diagnosis of aneurysmal bone cyst; Under general anesthesia and fluoroscopic guidance, intralesional puncture with 16G needle was performed through which 3% polydocanol was slowly administered. Data: medical history. Quantitative variables shall be expressed in measures of central tendency and dispersion; qualitative variables shall be expressed as frequencies or percentages. RESULTS: Nine consecutive patients were included, all of whom had pain and tumor in one of the extremities. Gender: 3 female and 6 male. Age: median 10.5 years (range: 2-15.1). Weight: median 32.8 kg (range: 11-44.5). Total procedures: 44; procedures per patient: mean 4.9 (SD: ± 2.0). Procedure time: mean 33.9 minutes (SD: ± 18.3); radiation: mean 1.34 mGy (SD: ± 1.55). Hospitalization: one day, except one patient. Complications: skin damage in one case, no recurrences follow-up: 12 to 50 months. CONCLUSION: In this pediatric series, polydocanol 3% was useful and effective for the treatment of aneurysmal bone cyst, with few complications. One disadvantage is that it requires several sessions and in addition, no significant difference has been demonstrated between other forms of treatment in terms of the recurrence rate.

INTRODUCCIÓN: El quiste óseo aneurismático es un raro tumor osteolítico benigno, pero agresivo para el que aún no existe tratamiento ideal. Los comunicados sobre tratamiento mediante escleroterapia en población pediátrica son escasos y en nuestra región más aún. El objetivo es comunicar la experiencia del tratamiento del quiste óseo aneurismático con polidocanol 3%. MATERIAL Y MÉTODOS: Estudio retrospectivo, descriptivo y transversal. Período: Junio de 2017 a Junio de 2021. Inclusión: pacientes con diagnóstico histológico de quiste óseo aneurismático. Bajo anestesia general y guía fluoroscópica se realizó punción intralesional con aguja 16G a través de la cual se administró lentamente el polidocanol 3%. Datos: historia clínica. Las variables cuantitativas se expresarán en medidas de tendencia central y de dispersión; las variables cualitativas se expresarán como frecuencias o porcentajes. RESULTADOS: Se incluyeron nueve pacientes consecutivos, todos presentaban dolor y tumoración en alguna de las extremidades. Género: tres femeninos y seis masculinos. Edad: mediana 10.5 años (rango: 2-15.1). Peso: mediana 32.8 kg (rango: 11-44.5). Total de procedimientos: 44, procedimientos por paciente: promedio 4.9 (DE: ± 2.0). Tiempo de procedimiento: promedio 33.9 minutos (DE: ± 18.3); radiación: promedio 1.34 mGy (DE: ± 1.55). Hospitalización: un día, excepto un paciente. Complicaciones: Daño de piel en un caso, no recidivas. Seguimiento: de 12 a 50 meses. CONCLUSIÓN: En esta serie pediátrica el polidocanol 3% fue útil y efectivo para el tratamiento del quiste óseo aneurismático con escasas complicaciones. Una desventaja es que requiere varias sesiones y además, no se ha demostrado una diferencia significativa entre otras formas de tratamiento en términos de la tasa de recurrencia.

[Aneurysmal bone cyst in the sacrum: Case report and literature review]. / Quiste óseo aneurismático en el sacro: caso clínico y revisión de la literatura.

Aneurysmal bone cysts are rare benign bone lesions. Location in the sacrum is unusual. Symptoms are nonspecific. After an injury, pain develops and complications of adjacent structures can be triggered by the associated oedema. Radiological presentation is usually characteristic but must be confirmed by biopsy and a differential diagnosis must be made with other tumours. Treatment in long bones is based in curettage and refill with bone replacement material. In the sacrum, neurological complications can develop with selective arterial embolisation being an alternative in their management. We describe the case of a 71-year-old male patient with sacral aneurysmal bone cysts and a history of chronic lymphoid leukaemia and benign prostatic hyperplasia. The report includes the clinical presentation, imaging findings and outcome after treatment with selective arterial embolisation. This case highlights the therapeutic options and difficulties encountered in the management of these lesions when located in the sacrum, which complicates their usual treatment. Selective arterial embolisation is a therapeutic option in patients with sacral aneurysmal bone cysts, allowing less aggressive treatments and favourable results.

Qualitative evaluation of MRI features in aneurysmal bone cysts after percutaneous sclerotherapy.

OBJECTIVE: To report MRI findings of changes seen in aneurysmal bone cysts after percutaneous sclerotherapy treatment. MATERIALS AND METHODS: After applying exclusion criteria, a total of 36 patients who had aneurysmal bone cysts and undergone percutaneous sclerotherapy were included in this study. The pre-treatment and post-treatment MRIs were reviewed and multiple pre-determined MRI findings were evaluated. The presence of each post-treatment finding, as well as the time for each finding to develop, was recorded. RESULTS: Early post-sclerotherapy changes include increased perilesional edema and enhancement, which appear on MRI on average 5.1 months after the initial sclerotherapy. This is followed by decreased cystic areas, which can be seen on average 5.9 months after the initial treatment. The presence of fibrosis, improved cortical integrity, and improving mass effect are later post-treatment changes and appear on MRI on average 9.7 months, 10.6 months, and 16.1 months after the initial sclerotherapy, respectively. CONCLUSION: The early and late post-sclerotherapy MR findings of aneurysmal bone cysts were reported in this study.

Manejo del quiste óseo aneurismático acetabular con doxiciclina intralesional: a propósito de un caso / Acetabular aneurysmal bone cyst treated with intralesional doxycycline: a case report

Los quistes óseos aneurismáticos (QOA) son tumores benignos, expansivos, osteolíticos y localmente agresivos que se localizan principalmente en la metáfisis de los huesos largos. Aparecen predominantemente en niños y adultos jóvenes. La eliminación del QOA mediante cirugía conlleva altas tasas de recurrencia por lo que se emplean otras técnicas no quirúrgicas como las inyecciones intralesionales con doxiciclina. Se presenta el caso clínico de un niño de 7 años diagnosticado de quiste óseo aneurismático acetabular que fue tratado exitosamente con una dosis de 200 mg de doxiciclina intralesional previa aspiración de las cavidades para despresurizarlas. El paciente mostró reducción de la lesión y mejoría clínica tras la intervención, sin manifestaciones de recurrencia tras 34 semanas de seguimiento. (AU)

Aneurysmal bone cysts (ABCs) are benign, expansile, osteolytic and locally aggressive tumors. Typically, ABCs arise in metaphysis of long bones. They often appear in children and young adults. Wide en bloc resection is associated with high recurrence rates. Other non-surgical treatment methods include intralesional injections of doxycycline. We present the case of a 7-year-old male with acetabular ABC who was successfully treated with 200 mg of intralesional doxycycline. During surgery, one needle was used for aspiration to lower the injection pressure. At 34 weeks follow up, we observed a lesion volume reduction and the patient presented an improvement of symptoms without recurrence. (AU)

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

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

Pediatric Cervical Aneurysmal Bone Cyst Treated by Endovascular Approach.

INTRODUCTION: Aneurysmal bone cyst (ABC) is a rare, benign, and expansible bone lesion, occurring mainly in childhood. Although most lesions are located at the metaphysis of long bones, they can also be found in flat bones and spine. CASE PRESENTATION: We report a case of a 16-year-old boy with cervical ABC treated by endovascular embolization. The afferents were occluded as a preoperative preparation for surgery; however, as the patient became asymptomatic after the procedure, the family refused surgery. Image at 1-year follow-up showed reduction and ossification of the lesion. CONCLUSION: Endovascular treatment decreases surgical morbidity by reducing blood loss, which is particularly important in the pediatric population. This therapeutic option may also halt ABC growth in selected cases.