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

Aneurysmal bone cyst-like changes developed in melorheostosis with epiphyseal osteopoikilosis

Aneurysmal bone cyst (ABC) is a rare and usually painful condition, representing about 1% of all bone tumors. A geographical lytic, expansile, and septated radiological pattern, with fluid-fluid levels on MRI, is classically displayed. ABC can be a primary bone lesion (70% of patients) or can arise in an underlying condition and is subsequently named "ABC-like changes" (30%). ABC-like changes are more frequently encountered in skeletal segments affected by chondroblastoma, fibrous dysplasia, giant cell tumor, osteoblastoma, non-ossifying fibroma, and osteosarcoma. In this article, we describe the first case of ABC-like changes developed in association with an ultra-rare sclerosing bone disease: melorheostosis. Melorheostosis is characterized by recognizable patterns on radiological studies with a pathological increased bone density and a cortical thickening within the periosteal or endosteal space, usually with a "dripping candle wax" appearance. More rarely, other different radiological patterns can be observed, such as "osteopatia striata-like," "osteoma-like," "myositis ossificans-like," and mixed patterns. Pain and limb hypotrophy are the most common clinical manifestations. We report the case of a Caucasian male with a clinic-radiological diagnosis of melorheostosis (with epiphyseal osteopoikilosis) since the age of twelve. At the age of nineteen, he suffered from increased pain in the proximal right thigh, and the radiological control revealed an expansive septated lesion at the right proximal femoral bone. The diagnosis of ABC-like changes developed in melorheostosis was obtained after CT-guided bone biopsy and confirmed by open-incisional biopsy.

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.

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.

Neoplastic and Non-neoplastic Bone Lesions of the Knee

Numerous anatomical variants are described around the knee, many of which look like bony lesions, so it is important to know them to avoid unnecessary complementary tests and inadequate management. Likewise, several alterations in relation to normal development can also simulate bone lesions.However, numerous pathologic processes frequently affect the knee, including traumatic, inflammatory, infectious, and tumor pathology. Many of these entities show typical radiologic features that facilitate their diagnosis. In other cases, a correct differential diagnosis is necessary for proper clinical management.Despite the availability of increasingly advanced imaging techniques, plain radiography is still the technique of choice in the initial study of many of these pathologies. This article reviews the radiologic characteristics of tumor and nontumor lesions that may appear around the knee to make a correct diagnosis and avoid unnecessary complementary radiologic examinations and inadequate clinical management.

Keratin-Positive Giant Cell-Rich Tumor: A Review and Update

Keratin-positive giant cell-rich tumor (KPGCT) is an extremely rare and recently described mesenchymal neoplasm that occurs in both soft tissue and bone, frequently found in young women. It has locally recurrent potential if incompletely excised but low risk for metastasis. KPGCT is histologically similar to conventional giant cell tumors of soft tissue but shows the presence of keratin-positive mononuclear cells. Interestingly, KPGCT also shares some morphological features with xanthogranulomatous epithelial tumors. These two tumors have recently been shown to harbor an HMGA2-NCOR2 fusion, arguing in favor of a single entity. Surgery is the treatment of choice for localized KPGCT. Therapeutic options for advanced or metastatic disease are unknown. This review provides an overview of the current knowledge on the clinical presentation, pathogenesis, histopathology, and treatment of KPGCT. In addition, we will discuss the differential diagnosis of this emerging entity.

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.

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.

Acetabular Aneurysmal Bone Cyst During the Syrian Conflict: A Case Report of Surgical Treatment and Outcomes

Aneurysmal bone cysts (ABCs) are uncommon benign bone lesions that consist of blood-filled vascular spaces surrounded by fibrous tissue septa. Their diagnosis and surgical management are challenging in a war-torn region. In this case report, we present a rare case of a giant aneurysmal bone cyst located around the acetabulum in a 10-year-old female child who presented with an antalgic limp and left hip pain. The lesion was successfully treated with curettage and mixed autologous and synthetic bone grafts, and the follow-up for two years revealed a complete resolution of symptoms and radiological evidence of bone regeneration. This case highlights the successful surgical treatment of a challenging case of ABC in a difficult setting during the Syrian conflict.

Unusual presentation of aneurysmal bone cyst (ABC) in children: pediatric intracranial osteosarcoma with secondary ABC

A 13-year-old female patient presented with painless vision loss and proptosis for 18 months. Imaging findings were highly suggestive of a supraorbital aneurysmal bone cyst (ABC) for which she underwent complete surgical excision. Postoperatively, she developed left hemiparesis. Computed tomography angiography (CTA) revealed right complete internal carotid arterial (ICA) thrombosis. This was managed conservatively, and she improved in hemiparesis over the next 3 weeks. Histopathology report revealed osteosarcoma with secondary ABC, for which she was referred for radiotherapy. At 1.5 months follow-up, the patient's left lower limb power improved to 4 + /5. She was walking without support, and her left upper limb power was 4/5.

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.

Diagnosis and Current Treatment of Aneurysmal Bone Cysts

The purpose of this review is to increase awareness about the evolution and development of current trends in the diagnosis and treatment of aneurysmal bone cysts (ABCs). ABCs are benign, but locally aggressive bone tumors that mainly affect children. ABCs comprise 1% of all primary bone tumors and occur most frequently during the first two decades of life. The diagnosis is made using a variety of imaging modalities and has the characteristic features of an expansile, radiolucent lesion that is often seen in the metaphyseal region of the bone and has fluid-fluid levels that are apparent on MRI. In the pediatric population, telangiectatic osteosarcoma and unicameral bone cyst (UBC) are the main differential diagnoses of an ABC. Giant cell tumors (GCTs) also include in differential diagnosis, which often manifest in patients older than 15 and do not penetrate the open physis although they develop after the physeal closure. Imaging alone cannot rule out telangiectatic osteosarcoma; therefore, a biopsy is recommended. A variety of treatment options have been described; traditionally, most patients are treated with curettage and bone grafting. Curettage alone, however, usually results in tumor recurrence following excision. A variety of adjuvants have been utilized with varying degrees of effectiveness to reduce the risk of local recurrence. When a cyst is in the pelvis, its location and size are such that surgery is a very risky option. Selective arterial embolization has significantly contributed to the development of effective treatments for these situations. Embolization or radiation, as well as denosumab therapy, are widely used as therapies for ABCs in anatomic locations where surgery would significantly increase morbidity.

Adjunct role of liquid absolute alcohol intralesional sclerotherapy during the surgical management of spinal primary aneurysmal bone cyst in a child: a technical case report

BACKGROUND

Aneurysmal bone cyst is composed of variable -sized cystic blood-filled spaces separated by connective tissue septae. First-line surgical resection of spinal aneurysmal bone cyst in a child with limited total blood volume can lead to massive intraoperative bleeding, thus limiting extent of resection. Our Centre's has good experience of using absolute alcohol as an effective immediate devascularizing agent during vertebral hemangioma surgery in children.

MATERIAL AND METHODS

We report the first case of pediatric lumbar primary aneurysmal bone cyst in which completely blood-less piecemeal total resection of the lesion was performed after intraoperative absolute alcohol intralesional sclerotherapy.

RESULTS

Completely blood-less piecemeal total resection of the lumbar aneurysmal bone cyst was performed after intraoperative absolute alcohol intralesional sclerotherapy.

CONCLUSION

Intraoperative absolute alcohol intralesional sclerotherapy is a very effective devascularizing adjunct for complete piecemeal resection of spinal aneurysmal bone cyst in children with limited blood volume.

Benign tumors of the chest wall

Benign tumors of the chest wall are rare tumors that might arise from all the tissues of the chest: vessels, nerves, bones, cartilage, and soft tissues. Despite benign features, these tumors can have several histological characteristics and different behaviors. Even if they do not influence life expectancy, rarely they may have a potential risk of malignant transformation. They can cause several, oft, unspecific symptoms but more than 20% of affected patients are asymptomatic and are being diagnosed incidentally on chest radiograph or computed tomography scan. Pain is the most common described symptom. Together with a detailed medical history, a rigorous and meticulous clinical and radiological assessment is mandatory. If radiological features are unclear or in case surgery could not be performed, a biopsy should be indicated to establish a diagnosis. Radical surgical resection can often be offered to resect and cure these neoplasms, but this is might not be true for all types of tumors and, in some cases, their dimension or position might contra-indicate surgery. Given the rarity of these tumors, there is a lack of treatment's guidelines and prospective trials that include a significant number of patients. This review discusses, according to the latest evidence, the histological features and the best treatment of several chest wall benign tumors.

Use of Surgical Adjuvants Does Not Decrease Recurrence of Aneurysmal Bone Cysts in Surgical Intervention With Pediatric Patients

BACKGROUND

Aneurysmal bone cysts (ABCs) are benign active tumors often requiring intralesional curettage with or without adjuvants. The primary aim of this study was to analyze whether recurrence is influenced by the use of surgical adjuvants in pediatric patients with ABCs. Secondary aims examined recurrence rates based on age, sex, and physeal contact.

METHODS

A retrospective review was performed at a tertiary pediatric hospital from 2004 to 2020. Inclusion criteria consisted of patients treated surgically for histologically confirmed ABCs with a minimum of 6 months follow-up. Patients with treatment for a recurrent tumor or incomplete records were excluded. Patient demographics, location of the lesion, treatment technique, and incidence of recurrence were collected. Statistical analyses were performed using STATA.

RESULTS

There were 129 patients (74 males and 55 females) with a mean age of 11.5 ± 4.1 years and an average follow-up of 29.0 ± 25.4 months. The most common locations for ABCs were the femur and tibia. Of the patients, 53.5% had tumors abutting the physis, 28.7% had no physeal contact, and 17.8% had insufficient imaging to evaluate physeal contact. Surgical adjuvants (high-speed burr, coagulation, liquid nitrogen, and/or hydrogen peroxide) were used in 91 of the 129 cases (70.5%). There was no significant difference in recurrence when comparing those who received an adjuvant and those who did not (25.3% vs 23.7%, P = 1.000). Physeal contact was also not significantly associated with recurrence ( P = 0.146). Finally, patients younger than 6 years old were significantly more likely to have recurrence compared with those 6 years old or older (66.7% vs 21.7%, P = 0.007).

CONCLUSION

Our study found no association between the use of surgical adjuvants and the risk of recurrence after intralesional curettage for ABCs. Although our study did demonstrate that patients 6 years old or younger had an increased rate of recurrence, no significant association was found regarding physeal contact or sex. These data indicate that surgical adjuvant may not affect the recurrence rates of pediatric patients with ABCs.

LEVEL OF EVIDENCE

Level III. This retrospective review compares rates of recurrence based on the choice of surgical adjuvant.

Novel method to biopsy aneurysmal bone cysts in children

PURPOSE

The thin and friable septations composing aneurysmal bone cysts (ABC) may be challenging to target for percutaneous biopsy. The purpose of this study was to describe and evaluate a novel method of ABC biopsy using endomyocardial biopsy forceps as an attempt to capture larger fragments of tissue for diagnosis.

METHODS AND MATERIALS

This was a retrospective study performed over a 17-year period. Patients <18 years old who underwent percutaneous biopsy for a presumed ABC, based on pre-procedure imaging, were included. Medical records were reviewed to identify age, sex, lesion location, biopsy procedure details, complications, and pathology results. A diagnostic biopsy was defined as conclusive histologic confirmation. Inconclusive findings or findings suggestive of but not diagnostic of an ABC were treated as non-diagnostic, even if imaging and clinical findings were characteristic. Biopsy device selection and quantity of tissue obtained was at the discretion of the pediatric interventional radiologist. Fisher's exact test was used to compare the diagnostic yield of standard biopsies to those employing biopsy forceps.

RESULTS

Twenty-three biopsies were performed in 18 patients (11 female) with a median age of 14.7 years (IQR 10.6-15.6). Lesions were located in the extremities (7, 30.4%), chest (6, 26.1%), pelvis (5, 21.7%), spine (4, 17.4%), and mandible (1, 4.3%). Specimens were obtained using a 13- or 15-gauge bone coring needle (11, 47.8%); 14-, 16-, or 18-gauge soft tissue needle (6, 26.1%); or a combination of bone and soft tissue (4, 17.4%) needles. Endomyocardial biopsy forceps were utilized in 7 cases (30.4%), 2 in which it was the only device used. Overall, a conclusive pathologic diagnosis was made in 13/23 (56.5%) biopsies. Of the diagnostic biopsies, 1 was a unicameral bone cyst and all others were ABCs. No malignancy was identified. Compared to the standard approach, the use of forceps was more likely to result in a diagnostic biopsy (40.0% vs 100.0%, p = 0.008). There were no complications.

CONCLUSIONS

Endomyocardial biopsy forceps offer an additional, novel technique to biopsy presumed ABCs and may improve diagnostic yield.

Langerhans cell histiocytosis with aneurysmal bone cyst-like changes: a case-based literature review

BACKGROUND

Langerhans cell histiocytosis (LCH) is a neoplastic transformation of myeloid precursors that commonly presents as an osteolytic lesion of the long or flat bones in children. Aneurysmal bone cysts (ABC) are benign neoplasms that frequently affect the metaphysis of long bones and the spine, often revealing a rapidly expansile lesion with fluid-fluid levels. LCH with secondary ABC-like changes is a rare condition that has only been reported five times, with two presentations in the cranium. The aim of this paper is to review the etiology, clinical and radiographic presentations, and treatment of this condition, as well as to present a novel case on the topic.

CASE DESCRIPTION

We describe a 5-year-old boy with a rapidly growing head mass and eye pain resulting in a diagnosis of LCH with secondary ABC-like changes. Radiography demonstrated an expansile, lytic lesion of the left parietal bone with fluid-fluid levels. A confirmatory diagnosis was made through histopathology, demonstrating an inflammatory, histiocytic infiltrate staining positive for CD1a, CD68, CD207 (Langerin), and S-100. The lesion was surgically excised, and the patient recovered without any complications.

CONCLUSION

We present a novel case of LCH with secondary ABC-like changes managed with surgical excision. While a radiographic workup with multiple imaging modalities is helpful for diagnosis, a thorough immunohistochemical analysis is essential as imaging characteristics are variable and nonspecific. Furthermore, surgical excision should be considered first-line treatment for lesions involving the skull in surgically accessible areas as it is curative, alleviates symptoms, and allows for histopathological diagnosis.

Aneurysmal bone cyst arising from the surgically removed craniofacial fibrous dysplasia in the long-term follow-up: a case report

Fibrous dysplasia (FD) is a rare skeletal disorder characterized by abnormal fibro-osseous connective tissue replacing normal bone. Despite its benign behavior, craniofacial FD can cause morphological disfigurement, headache, and even blindness as a result of the produced mass effect. Surgical resection is recommended when the patient shows apparent clinical symptoms or aggravating facial asymmetry. Postoperative complications have been reported, such as hematoma, surgical site infection, abscess formation, resorption of the bone graft used for reconstruction, and recurrence. An aneurysmal bone cyst (ABC) is a rare benign bony lesion that can occur secondary to preexisting bone tumor. Secondary ABCs in craniofacial FD are extremely rare in the literature, accounting for less than 30, all of which are either case reports or series. We report an extremely rare case of symptomatic secondary ABC arising from craniofacial FD that had been misdiagnosed with abscess formation or recurrence and was surgically removed. Notably, 17 years elapsed between the primary surgery and the complication of secondary ABC. The patient underwent total removal of secondary ABC. After surgery, symptoms were relieved, with no recurrence observed during a 6-month follow-up.

Aneurysmal Bone Cyst of the Pelvis in Children and Adolescents: Effectiveness of Surgical Treatment with Curettage, Cryotherapy and Bone Grafting

BACKGROUND

Aneurysmal bone cysts (ABCs) are benign but locally aggressive cystic lesions of the bone. Pelvic ABCs are extremely rare and hard to treat due to their high risk of local recurrence and the tough access to pelvic bones.

METHODS

In this retrospective study, we evaluated pediatric cases with pelvic ABC treated with curettage, cryotherapy and bone grafting treated in our institution between 2016 and 2022. Complications were recorded, as well as local recurrences. Patients' post-operative functionality was assessed with the MSTS score.

RESULTS

Fourteen consecutive cases were included in our study. Their mean age at surgery was 13.5 years. The mean lesion size was 55 mm. The mean follow-up was 38 months. Two cases (11.8%) had local recurrences, which were successfully treated with further curettage. At their latest FU, 13 cases were continuously disease free (CDF), and one had no evidence of disease (NED). Only one case had a post-operative compilation (wound dehiscence). Patients' mean post-operative MSTS score was 29.6.

CONCLUSIONS

Pelvic ABCs are a challenge, even for the most experienced orthopedic surgeon. Our study suggests that the association of an accurate curettage, intraoperative cryotherapy and bone grafting can be a reliable and effective therapeutic option for large-sized ABCs of the pelvis.

Surgery for fibrous dysplasia associated with aneurysmal-bone-cyst-like changes in right proximal femur: A case report

BACKGROUND

Fibrous dysplasia associated with aneurysmal bone cyst (ABC)-like changes in the right proximal femur has a low incidence. It is considered more difficult to make early diagnosis than for single fibrous dysplasia.

CASE SUMMARY

A 14-year-old woman was admitted because of persistent pain in the right hip and abnormal gait over the previous 2 mo. She had no history of present or past illness. Preoperative photography, enhanced computed tomography, and magnetic resonance imaging showed ground-glass appearance with cortical scalloping and expansion of the right proximal femur and femoral neck. Pathological examination by preoperative puncture biopsy revealed fibrous dysplasia of the right proximal femur. The patient was diagnosed with fibrous dysplasia based on medical history, physical examination, and results of laboratory, imaging and pathological examinations. According to final pathological examination, the patient was diagnosed with fibrous dysplasia of the right proximal femur associated with ABC. Curettage and allograft along with fixation of compression screws was performed for fibrous dysplasia associated with ABC-like changes. No obvious allograft absorption, loosening of fixation, or secondary fracture were observed during 6-months' follow-up with re-examination by plain radiography and computed tomography. Fibrous dysplasia associated with ABC-like changes in the right proximal femur has a low incidence and early diagnosis is considered more difficult than for single fibrous dysplasia.

CONCLUSION

We report a cases of fibrous dysplasia associated with ABC-like changes in the right proximal femur treated with curettage and allograft along with hip compression screws.

Restoration of Limb Length Discrepancy and Alignment With the Ilizarov Device After Management of an Aneurysmal Bone Cyst Crossing the Distal Femoral Physis

An aneurysmal bone cyst (ABC), when located juxta-physeal, may rarely penetrate the growth plate and extend into the epiphysis. The recurrence rate is considered higher when ABC is in contact with the active growth plate. Treatment methods usually focus on cyst healing and the rate of cyst recurrence. We present the method of treatment used for addressing the lesion of the growth plate following the surgical management and healing of a juxta-physeal ABC. A seven-year-old girl had an aggressive ABC in the juxta-physeal area of the distal femur, penetrating the growth plate and extending in the epiphysis. Surgical treatment was performed, including curettage and autologous bone grafting, avoiding the growth plate. The cyst healed; however, physis presented an obliteration. The affected limb developed valgus deformity and severe leg length discrepancy (LLD). To address this issue, once our patient completed her growth, we proceeded with distraction osteogenesis, using the Ilizarov device, with asymmetrical lengthening of the rods. We achieved the correction of the limb alignment and resolved the LLD. ABCs in the juxta-physeal area of a growing child are benign metaphyseal tumors that exceptionally may penetrate the physis and extend into the epiphysis. Our report highlights that the growth plate's lesion, despite the cyst's healing, may compromise the final result. The use of the Ilizarov device is an effective method for correcting the malalignment and the LLD that may emerge.

Imaging of Common and Infrequent Extradural Tumors

Spinal extradural tumors, although uncommon, have high morbidity and mortality rates. Radiographs and computed tomography scans are typically used to assess and determine the characteristics of these tumors. However, MR imaging is the preferred method for the evaluation of complications that can increase morbidity, such as spinal cord and nerve compression. Imaging features, such as type of matrix, cortical involvement, and margins, aid in determining the diagnosis. This article discusses common and infrequent extradural spinal tumors, their imaging characteristics, and how age, location, and clinical presentation help in diagnosing these neoplasms.

Screening of renal clear cell carcinoma prognostic marker genes based on TCGA and GTEx chip data and construction of transcription factor-related regulatory networks

This study aimed to identify prognostic marker genes for renal clear cell carcinoma (RCCC) and construct a regulatory network of transcription factors and prognostic marker genes. Three hundred eighty-six genes were significantly differentially expressed in RCCC, with functional enrichment analysis suggesting a relationship between these genes and kidney function and development. Cox and Lasso regression analyses revealed 10 prognostic marker genes (RNASET2, MSC, DPEP1, FGF1, ATP1A1, CLDN10, PLG, SLC44A1, PCSK1N, and LGI4) that accurately predicted RCCC patient prognosis. Upstream transcription factors of these genes were also identified, and in vitro experiments suggested that ATP1A1 may play a key role in RCCC patient prognosis. The findings of this study provide important insights into the molecular mechanisms of RCCC and may have implications for personalized treatment strategies.

A large aneurysmal bone cyst of mandible: A rare case report

An aneurysmal bone cyst (ABC) is a rare benign tumor-like lesion, described as an expanding osteolytic lesion consisting of blood-filled spaces of variable sizes separated by connective tissue septa. It is frequently accompanied by multiple cystic lesions due to aggressive hemodynamics with reactive bone formation and a genetic predisposition. This lesion has been classified as an atypical giant cell tumor or benign bone cyst. ABC has an incidence of 0.5% and comprises approximately around 1.5% of all non-odontogenic and non-epithelial cysts of the jaws. About 50% of the ABCs are reported in long bones and the vertebral column and only 2% have been reported to involve jaw bones. This case report gives an overview of a very large size ABC of the mandible in a 14-year-old male patient.

Imaging of Skull Base Tumors

The skull base provides a platform for supporting the brain while serving as a conduit for major neurovascular structures. In addition to malignant lesions originating in the skull base, there are many benign entities and developmental variants that may simulate disease. Therefore, a basic understanding of the relevant embryology is essential. Lesions centered in the skull base can extend to the adjacent intracranial and extracranial compartments; conversely, the skull base can be secondarily involved by primary extracranial and intracranial disease. CT and MRI are the mainstay imaging methods and are complementary in the evaluation of skull base lesions. Advances in cross-sectional imaging have been crucial in the management of patients with skull base pathology, as this represents a complex anatomical area that is hidden from direct clinical exam. Furthermore, the clinician must rely on imaging studies for therapy planning and to monitor treatment response. It is crucial to have a thorough understanding of skull base anatomy and its various pathologies, as well as to recognize the appearance of treatment-related changes. In this review, we aim to describe skull base tumors and tumor-like lesions in an anatomical compartmental approach and present imaging methods that aid in diagnosis, management, and follow-up.

Skull base chondroblastoma with aneurysmal bone cyst-like changes treated with percutaneous radiofrequency ablation and doxycycline sclerotherapy: illustrative case

BACKGROUND

Chondroblastomas (CBs) are rare benign bone tumors that are often difficult to treat because of their locations. CBs can be even more challenging to successfully manage when they present alongside aneurysmal bone cyst (ABC)-like changes. To minimize operative morbidity, especially in hard-to-reach lesions, percutaneous approaches for both lesions have been individually described. We present a skull base CB with associated ABC-like changes treated by combining two different previously described percutaneous modalities.

OBSERVATIONS

The authors report successful percutaneous treatment of a skull base CB with adjacent ABC-like changes in a 17-year-old male. The CB was treated with radiofrequency ablation (RFA) and the adjacent ABC area with doxycycline sclerotherapy. After 3 years of follow-up, there has been no clinical or radiological evidence of recurrence.

LESSONS

CBs occur in the skull base and, as elsewhere in the body, can be associated with ABC-like changes. Successful percutaneous treatment of such a CB with ABC-like changes is possible by combining previously described techniques of RFA and doxycycline sclerotherapy.

Soft tissue aneurysmal bone cyst in thigh muscles: A case report

Aneurysmal bone cysts (ABCs) are benign lesions that are locally invasive. The prevalence of soft tissue ABCs is far lower than the intraosseous type. Here, we report a case of ABC in thigh muscles who presented with distal thigh pain.