Nanopore DNA Sequencing Detected Chromothripsis-Induced PAFAH1B1::USP6 Rearrangement in Periosteal Solid Aneurysmal Bone Cyst Initially Diagnosed as Osteosarcoma.

An aneurysmal bone cyst (ABC) is a benign bone neoplasm that typically occurs during the first and second decades of life. ABC usually presents as a rapidly growing intramedullary expansile mass with multiple blood-filled cysts in the metaphysis of the long tubular bones. Here, we report a case of a periosteal solid ABC that was initially diagnosed as a high-grade surface osteosarcoma. A 10-year-old male was referred to our hospital for swelling and tenderness of the left upper arm. Radiography revealed periosteal mass without fluid-fluid levels. On performing open biopsy, the tumor showed hypercellular proliferation of uniform spindle to epithelioid cells with brisk mitotic activity (up to 12/2 mm2) and lace-like osteoid formation, which was diagnosed as a high-grade surface osteosarcoma. After one course of chemotherapy using adriamycin and cisplatin, peripheral sclerosis was conspicuous, which led to pathological review and revision of diagnosis as "possibly osteoblastoma." The patient was disease-free for 4 years after marginal resection and curettage. Retrospective nanopore DNA sequencing unexpectedly detected a PAFAH1B1::USP6 rearrangement. The fusion gene was further validated using reverse transcription-polymerase chain reaction and the diagnosis was revised to ABC. Chromothripsis involving chromosome 17 has also been identified. Methylation analysis classified the present tumor as an ABC or non-ossifying fibroma using t-distributed stochastic neighbor embedding and unsupervised hierarchical clustering. This case report highlights the utility of nanopore DNA sequencing for soft tissue and bone tumor diagnosis.

Aneurysmal Bone Cyst in the Anterior Region of the Mandible.

Aneurysmal bone cyst is a rare osteolytic lesion of uncertain etiology, commonly observed in the lower limbs, with only 1-2% of reports in gnathic bones. We present the case of a 27-year-old male patient referred to the oral and maxillofacial surgery and traumatology service due to complaints of paresthesia in the mental region and increased mandibular volume. Physical examination revealed midline shift and hard consistency. Imaging examinations demonstrated a radiolucent/hypodense lesion with disruption of the mandibular cortices. The histopathological examination of incisional biopsy material led to the diagnosis of a central giant cell lesion. The patient underwent surgical resection, and the histopathological analysis of the specimen revealed a predominantly solid lesion, characterized by blood-filled spaces of varying size, not covered by epithelium or endothelium, with the presence of spindle cells, multinucleated giant cells, and basophilic osteoid material, concluding the diagnosis of mixed-type aneurysmal bone cyst. Despite being uncommon, aneurysmal bone cysts should be considered in the differential diagnosis of volumetric increase in the gnathic bones of young patients.

Response of Recurrent Aggressive Aneurysmal Bone Cyst of Distal Tibia to Denosumab Treatment.

Introduction: Aneurysmal bone cysts (ABCs) are aggressive and benign tumors that primarily affect children and adolescents. The standard course of treatment for ABCs involves surgical excision or curettage with a bone transplant or cement to repair the deficiency. Denosumab, a monoclonal antibody that inhibits receptor activator of nuclear kappa B ligand, is used to treat osteoporosis, skeletal metastasis, and giant cell tumors of the bones. Case Report: This case study details the therapeutic treatment of a female patient, age 22, who had a recurring aggressive ABC of the distal tibia. The patient was initially treated using curettage and lesion filling. However, recurrence of the osteolysis was observed 9 months later that led to subsequent interventions involving absolute alcohol sclerotherapy in multiple sessions. However, these interventions failed to achieve ossification. Following unsuccessful surgical and sclerotherapy treatments, the patient was administered denosumab, which led to a positive response. Regular radiographic and clinical follow-up demonstrated significant improvements in ossification and pain reduction. During the course of the 12-month treatment, the frequency of visits was gradually reduced. Further, follow-up and monitoring revealed the effectiveness of the local control and long-term treatment. Conclusion: This case report highlights the ability of denosumab to manage recurrent aggressive ABCs after surgical or sclerotherapy failure.

A New Radiological Scoring System as a Method of Assessing Sclerotherapy Treatment Response for Aneurysmal Bone Cysts: A Retrospective Study.

Background A widely accepted set of imaging criteria or classification has not yet been adopted to evaluate response to treatment by percutaneous sclerotherapy for aneurysmal bone cyst (ABC). In this article, we described and illustrated the Royal Orthopaedic Hospital (ROH) scoring system which is a new, reproducible, and objective tool to evaluate the radiological response. We also reported our institutional experience in the efficacy of computed tomography (CT)-guided sclerotherapy for treating such lesions. Patients and Methods A retrospective analysis was conducted for 19 patients who underwent CT-guided sclerotherapy with doxycycline and albumin to treat ABC. Follow-up magnetic resonance imaging, at a minimum of 12 months, was assessed according to the four ROH scoring system parameters: cystic component, fluid-fluid level, presence of consolidation, and cortical integrity. The cumulative score was used to grade response as either: excellent, good, equivocal, or poor. Results Out of 19 patients with a mean age of 17.8 years, 11 cases occurred in the long bones, 5 cases in the pelvis, and 1 in each of the C3 vertebral body, scapula, and talus. The mean parameter of response score for cystic component was 2, fluid-fluid level was 1.3, consolidation was 2, and cortical integrity was 2.1. Four cases showed excellent response, 12 cases showed good response, 2 cases showed equivocal response, and 1 case showed poor response. Interrater reliability was excellent (κ = 0.9). Conclusion The ROH scoring system provides the radiologist and surgeon with an objective method to score imaging parameters of response independently and achieve a grade based on the cumulative score.

Giant Cell Tumor of the Anterior Arc of the Rib: A Case Report.

Tumors that develop on the chest wall are usually rare. This case report highlights a rare occurrence of a giant cell tumor originating from the anterior arch of the fourth rib. The patient, a 21-year-old male, presented with a bulging mass that had been gradually increasing in size over an eight-month period, reaching dimensions of 12 x 8 cm. Despite the noticeable swelling, the patient reported no associated pain or discomfort and denied any history of weight loss or trauma. The absence of chest pain or cardiovascular symptoms distinguished this case from other chest wall pathologies. This report underscores the importance of considering rare entities such as giant cell tumors in the differential diagnosis of chest wall masses, especially in cases where clinical presentation and patient history do not align with more common conditions.

Total Hip Arthroplasty in a Patient With a Large Proximal Femur Aneurysmal Bone Cyst: A Case Report and Literature Review.

Aneurysmal bone cysts (ABCs) are rare benign bone lesions with a predilection for the metaphysis of long bones. They are often cystic, expansive, and osteolytic and may result in bony deformity. In general, there remains debate about optimal treatment for ABCs; however, the mainstay typically consists of a combination of curettage, bone grafting, and considering the need for internal fixation and osteotomies. The goals of treatment include preserving bony anatomy while eliminating the lesion. There is sparse literature regarding the treatment of osteoarthritis adjacent to benign bony tumors. If total hip arthroplasty is chosen as a treatment option, diligent preoperative planning is required, and the surgeon must assess the patient's bone stock, account for bony deformity, and utilize specific implants and techniques based on the patient's characteristics. We present a case of an adult patient with proximal femur ABC and symptomatic adjacent hip osteoarthritis who underwent treatment with total hip arthroplasty.

Pathological Fractures in Aneurysmal Bone Cysts: A Systematic Review.

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

Management of Recurrent Giant Cell Tumor of Distal Tibia With Intramedullary Hindfoot Fusion Nail and Trabecular Metal Implant Construct.

Reconstruction options for giant cell tumors (GCTs) of bone are limited and challenging due to the amount of structural compromise and the high recurrence rates. This is especially true for GCTs of the foot and ankle, as the area is vital for weight bearing and function. The typical treatment for GCTs is currently excision, curettage, and cementation, although that is not always effective. A 36-year-old otherwise healthy female presented with an original diagnosis of a large aneurysmal bone cyst (ABC) of the distal tibia that had recurred despite two previous attempts at treatment with resection and cementation. She was treated with surgical resection of the lesion, reconstruction, and ankle and subtalar joint arthrodesis with a tibiotalocalcaneal intramedullary nail in combination with a trabecular metal cone. The final pathology of the intraoperative samples was consistent with GCT. Postoperatively, she recovered well, and her imaging was consistent with a successful fusion. This case report provides evidence that tibiotalocalcaneal fusion with a unique combination of hindfoot nail and trabecular metal cone construct in a single procedure is a successful option for the treatment of large, recurrent GCT lesions in the distal tibia.

Aneurysmal Bone Cyst of the Third Metatarsal Treated Using Free Nonvascular Fibular Strut Graft-A Rare Case Report.

Introduction: An aneurysmal bone cyst (ABC) is an unusual, non-cancerous bone lesion that is characterized by its lytic (causing bone loss), hemorrhagic, and expanding nature. ABCs are relatively rare, making up only 1% of all bone tumors. These cysts are typically found in long bones and the spine but are very rarely seen in the metatarsal bones, making such occurrences quite uncommon. Case Report: In this case report, we present a case of ABC of the 3rd metatarsal in a 26-year-old female with complaints of long-standing foot pain and gradually increasing swelling of the dorsum of the foot. After radiological evaluation, she had undergone histopathological evaluation. An en bloc resection of the metatarsal along with the tumor mass was performed and the gap was replaced with an ipsilateral fibular strut graft. Histopathological examination of the resected tissue was suggestive of ABC without any evidence of malignancy. At the end of 1 year of follow-up, she is now completely pain free with intact rom of foot and ankle. Conclusion: The present study aims to describe a case of ABC of the metatarsal, a condition that not only poses a diagnostic dilemma but also constitutes a challenge in the management of lesion.

Minimizing neurovascular complications during image-guided percutaneous cryoablation of a cervical spinal aneurysmal bone cyst using protective doxycycline sclerotherapy: a case report.

Background: Aneurysmal bone cysts (ABC) are rare, locally aggressive bone tumors primarily observed in pediatric patients. Surgical curettage is the treatment of choice. Image-guided percutaneous cryoablation (CYOA) is a recently implemented alternative technique in cases not amenable to surgery. CYOA may be limited if the lesion is close to critical neurovascular structures. In this case report, a cervical spinal ABC was successfully treated using CYOA in combination with complementary and protective image-guided percutaneous doxycycline sclerotherapy (DS) to dissect and treat the portion of the lesion in contact with critical structures. Case Description: A 4-year-old male presented with a symptomatic ABC within the C5 vertebral body, which encompassed the right vertebral artery and contacted the right C5-C6 spinal cord and nerve roots. After ruling out surgery due to the proximity of critical neurovascular structures, treatment with CYOA was performed. However, subsequent follow-up showed recurrence in the part of the lesion contacting critical structures. A second approach was then decided, using DS to dissect and treat the most vulnerable portion and CYOA to treat the remaining tumor. Follow-up showed almost complete sclerosis of the lesion and total resolution of symptoms 3 years after treatment. Conclusions: Using DS to dissect and treat the portion of the lesion in contact with critical neurovascular structures during CYOA treatment of a cervical spinal ABC allowed for a safe and effective approach in our case.

Isolated calvarial aneurysmal bone cyst in a pediatric patient: illustrative case.

BACKGROUND: Aneurysmal bone cysts (ABCs) are benign, osteolytic lesions that can occur in long bones, vertebrae, or rarely, the skull. Here the authors present the case of a 15-year-old male with a primary ABC of the left frontoparietal skull along with a review of the literature to provide insight into the nature of this rare disease. OBSERVATIONS: An otherwise healthy 15-year-old male presented with a tense, painful lesion of the left frontoparietal scalp. He could not identify any inciting trauma, but first noted the lesion less than 2 weeks prior to presentation with progressive enlargement. Cranial imaging revealed a lytic skull lesion with fluid-fluid levels suggestive of ABC. Curative therapy was provided via wide excision of the lesion and calvarial reconstruction of the resultant skull defect. This was performed without complication, and histopathological evaluation confirmed the diagnosis of primary ABC. LESSONS: ABCs of the skull are rare entities and most often arise in the skull base versus the calvaria. Typically, these lesions are associated with an underlying bone pathology (secondary ABCs) but can be rarely seen as isolated lesions (primary ABCs). Clinical management consists of excision and adjuvant therapy for underlying pathology where appropriate.

Pubic Aneurysmal Bone Cyst Following Penile Inversion Vaginoplasty: A Case Report.

Background: Aneurysmal bone cysts (ABCs) are aggressive, expansile, and locally destructive vascular lesions. The exact etiology of ABCs is currently unknown and hypothesized to be related to vascular malformations or disruption of osseous vascularity. To date, there have been no reports describing the development of pubic ABCs following penile inversion vaginoplasty (PIV). Methods: This report describes the development of a pubic ABC in a transgender patient who had previously undergone PIV, possibly indicating a very rare complication of this gender-affirming operation. Results: A 37-year-old transgender female was initially referred to the orthopedic oncology clinic for evaluation of a 12-month history of left hip and groin pain. She had undergone gender-affirming PIV about 19 months prior to presentation. Magnetic resonance imaging (MRI) with contrast revealed a low T1 signal intensity and heterogenous T2 hyperintensity 7.5 × 4.9 × 4.3-cm destructive mass in the left superior pubic ramus extending across the pubic symphysis into the right superior pubic ramus. A needle core bone biopsy demonstrated a variably cellular spindle and round lesion with islands of osteoid formation and focal necrosis. The cells were negative for CD34, S100, and desmin. There was no evidence suggesting osteosarcoma, and final review favored the diagnosis of an ABC. Given the highly destructive nature of the mass, it was resected, and the resulting wound was reconstructed with a biologic dermal mesh. Conclusions: Although it is impossible to distinguish coincidence from causation in this case, the patient's recency of PIV and development of a rare ABC in a nearby bone warrants the speculation and discussion provided in this report.

Tumors of the Posterior Elements of the Spine in Children-an Overview.

In this narrative review, we aim to describe the clinical features, diagnosis, and management of common primary osseous tumors affecting the posterior elements of the spine in children. We searched PubMed, Mendeley, and Google Scholar using the terms primary osseous tumors of the spine in children, tumors of the posterior elements of the spine, and names of individual tumors. The clinical features, investigations, and treatment modalities were analyzed, and a narrative review of the topic was prepared. We have included 54 studies published in the last 20 years. The majority are isolated reports or case series. Tumors of the posterior elements of the spine are rare. They are common in children and the majority of them are benign. Pain and deformity are common presentations. It is better to perform thorough investigations of children complaining of back pain to rule out primary tumors of the posterior elements of the spine.

Management of aggressive recurrent thoracic spine aneurysmal bone cyst in a 7-year-old male: A case report and review of the literature.

Background: Spinal aneurysmal bone cysts (ABCs) are rare, histologically benign tumors with aggressive behavior, which may cause bone and soft-tissue destruction, particularly affecting neural elements. Management of these tumors, including treatment modalities and follow-up protocols, remains challenging. Case Description: A 7-year-old boy presented with chest wall pain persisting for two months before admission, accompanied by progressive mono paresis lasting ten days before admission. Myelopathy signs were evident during the examination. Imaging confirmed a multicystic lesion at the T6 level involving the posterior elements of the vertebra, with significant cord compression. Due to deteriorating neurological function, he underwent urgent laminectomy and neural decompression, followed by subtotal tumor resection. Postoperative histopathological examination confirmed the diagnosis of an ABC, and the patient experienced significant neurological recovery. However, after 21 days, the patient was readmitted to the emergency department with severe paraparesis. Magnetic resonance imaging revealed rapid growth of the residual tumor, leading to cord compression. He underwent aggressive total tumor resection, T6 vertebral body corpectomy, and fixation with pedicle screws and cage insertion. Following the second surgery, prompt neurological recovery occurred. Conclusion: This rare case report emphasizes the importance of a close follow-up protocol for spinal ABCs in the pediatric population. It highlights the challenges in managing these tumors and the need for vigilant monitoring to detect and address rapid recurrences.

Fibrous dysplasia with aneurysmal bone cyst-like change occurring in pediatric orbit: case report and literature review.

PURPOSE: We report a case of fibrous dysplasia (FD) with aneurysmal bone cyst (ABC)-like change in a child with orbital involvement, review the related cases, and discuss clinical features, therapy, and prognosis of this disease. CASE PRESENTATION: A 10-year-old girl had right proptosis (degree of exophthalmos: OD 16 mm, OS 13 mm) and limited vision (visual acuity: OD 1.0, OS 0.8) without trauma. Preoperative CT showed a 5.0*4.3 cm right-sided crania-orbital communicating tumor. MRI indicated a well-defined multicystic mass with scattered fluid levels and soap bubble-like alterations. The child underwent total tumor resection and orbital parietal titanium mesh reconstruction. At 20 months of follow-up, the child has recovered from ocular problems, and the tumor has not recurred. CONCLUSION: FD combined with ABC rarely occurs in orbit and generally begins with ocular symptoms. The etiology is uncertain. Early diagnosis and surgery are essential. Complete resection is suggested whenever possible because residual lesions may recur.

A rare case of aneurysmal bone cyst of the anterior clinoid process in an 18-year-old female mimicking optic neuritis.

BACKGROUND: Aneurysmal bone cyst (ABC) is an uncommon, benign, vascular multicystic bony lesion that most frequently develops in the first two decades of life. The metaphysis of long bones, pelvic, and vertebral column are the most common locations. The precise underlying pathophysiology of ABCs formation remains unclear; however, it is believed that reactive processes subsequent to trauma or vascular disturbance may play an important role. Involvement of the skull base rarely occurs with a prevalence of up to 5% of intracranial ABCs. CASE PRESENTATIONS: An 18-year-old adolescent female with a history of progressive blurred vision since three months ago presented to our office. The brain and orbital MRI demonstrated no abnormal findings. After three months of glucocorticoid treatment with the diagnosis of multiple sclerosis, the visual impairment of the left eye deteriorated abruptly. The patient underwent an MRI and the imaging study demonstrated a well-defined 30 × 22 × 20-mm lesion at the anterior clinoid process with an extension to the optic canal and ethmoid sinus. The patient underwent pterional craniotomy, and the tumor was resected. The histopathological examination was suggestive of ABC. CONCLUSION: ABC and other conditions should be considered in young-age people with an early unilateral decline in vision and imaging studies should be obtained in early stages and during follow-ups.

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

Background: Aneurysmal bone cysts (ABCs) are infrequent, benign, and locally destructive lesions that most commonly occur during the first two decades of life. They usually affect the metaphysis of the long bones, but the pelvis is involved in 8%-12% of the cases. The management of pelvic ABCs is a challenging issue due to difficulties in choosing the appropriate approach, adjacent neurovascular bundles, the risk of intraoperative bleeding with difficulty achieving good hemostasis, and the risk of injury to the hip or sacroiliac joints. Limited data exist concerning the use of denosumab as a non-surgical treatment for pelvic ABCs. Our hypothesis was that denosumab might be an effective and safe solo treatment of cases with ABCs in the pelvis. Methods: We retrospectively assessed 20 patients with ABCs in the pelvis, who were treated by denosumab as a solo agent without surgery. Patients were assessed regarding disease control, the incidence of recurrence and non-oncological complications, and functional outcome. Results: The mean follow-up period was 38.5 months. Disease control was achieved in 16 patients (80%), with no local recurrence. Tolerable drug-related complications occurred in 15% of cases. The mean Musculoskeletal Tumor Society score was 92.3%. Conclusions: Denosumab may provide a reliable option in the nonsurgical treatment of ABCs of pelvic origin with expected lower morbidity than the surgical solution and tolerable complications. Further studies on the safety profile and long-term effects of denosumab especially in skeletally immature patients are required.

Gigantic aneurysmal bone cyst of the scapula in children treated with left total scapulectomy and humeral suspension: A case report.

INTRODUCTION AND IMPORTANCE: Aneurysmal bone cyst (ABC) is a benign, rapidly growing, osteolytic and could have hemorrhagic lesion. This cyst mostly occurs in females under 20 years old and is located predominantly in the metaphysis of long bones, followed by the pelvis and spine. ABC of the scapula is a rare case, and their treatment still remains controversial. CASE PRESENTATION: A 7-year-old girl has had a growing lump on her left shoulder since two years ago. Physical examination revealed local tenderness and a firm and immobile mass, which limit shoulder motion. The radiological and histopathological results confirmed the diagnosis of ABC of the scapula. The patient underwent a left total scapulectomy and humeral suspension reconstruction and was augmented with surgical mesh. There were no signs of postoperative infection or recurrence during the 1-year follow-up. The MSTS score was 24. CLINICAL DISCUSSION: There are many options for ABC treatment. Resection of the cyst is the treatment of choice for aggressive tumors (Enneking stage 3) or lesions in less essential bones. In scapula, the ABC treatment with total scapulectomy followed by humeral suspension is an effective method to decrease complications and reduce the risk of recurrence with a good clinical outcome. CONCLUSION: ABC of the scapula is a rare case. Tumor resection for aggressive ABC should be considered to decrease the recurrence rate. Total scapulectomy with humeral suspension is an effective method for treating ABC scapula (Enneking stage 3).

[Pediatric neurosurgical treatment of aneurysmal bone cyst at the level of thoracic spine]. / Aneurysmás csontcysta gyermek-idegsebészeti megoldása a háti gerinc magasságában.

Aneurysmal bone cysts are benign but locally aggressive bone tumours, most often affecting children and young adults. In this case report, we present the clinical  picture of a 15-year-old boy with progressive, chronic back pain. An MRI of thoracic spine  confirmed a T2 cystic spinal tumour. After considering potential options surgical removal was our choice and gross total removal was achieved with T1-3 short-segment fixation. Aneurysmal bone cysts are often rapidly expanding lesions with vascular  transformation. In order to avoid irreversible damage, in addition to early diagnosis, it is necessary to carefully consider the therapeutic options, perform surgical removal and stabilization as necessary. In case of the presented patient, extensive surgical removal and short-segmentation were performed. At 18 months of follow-up, he had no complaints and was asymptomatic. Follow-up imaging studies showed no residual or recurrent tumour to date.

Imaging of Fibro-osseous Lesions and Other Bone Conditions of the Jaws.

This review directs the focus on the imaging features of various fibro-osseous lesions and other bone lesions that can be of similar presentation. Broad diagnosis of "fibrous osseous lesion" may culminate in improper treatment and management. Radiographic discriminating factors between these entities are highlighted and summarized to improve the diagnostic process when encountering these lesions.