Cervical Spine Aneurysmal Bone Cyst in a Pediatric Patient: Embolization Considerations and Potential Pitfalls.

BACKGROUND: Aneurysmal bone cysts (ABCs) comprise 1%-2% of all bone tumors. ABCs involving the upper cervical spine in pediatric patients complicate intervention because of an immature skeleton and nearby neurovascular elements. Treatment often consists of surgical intervention with preoperative embolization to mitigate blood loss. During selective arterial embolization, it is important to be aware of extracranial-intracranial anastomoses from tumor feeding vessels. We describe a C2 vertebrae ABC that had multiple tumor arteries anastomosing with bilateral vertebral arteries. CASE DESCRIPTION: A 3-year-old healthy girl presented with 1 month of progressive neck pain and palpable posterior neck mass. Imaging was most consistent with an ABC of the C2 vertebra. Preoperative embolization was planned. Angiography demonstrated tumor arterial supply anastomosing with the left and right vertebral artery stemming from the ascending and deep cervical artery branches. Tumor embolization was therefore carried out using coils and larger embolization particles to decrease ischemic stroke risk. Follow-up angiography showed successful tumor embolization with no vertebrobasilar complications. Surgical excision was uncomplicated and the patient's cervical spine has remained stable without fusion. CONCLUSIONS: Preoperative embolization for ABC resection is common, but thorough angiography must be done to rule out dangerous extracranial-intracranial anastomoses. This case demonstrated 2 key anastomoses with the vertebral artery that if not recognized, could lead to disastrous consequences. Comprehensive angiographic evaluation is necessary because previous reports have described ischemic complications from embolization because of unrecognized vertebrobasilar anastomoses. If any angiographic evidence is seen, then larger particle size, coil embolization, or abandoning the case should be considered.

Successful NBCA embolization of a T2 aneurysmal bone cyst.

Surgically accessible aneurysmal bone cysts (ABC) have traditionally been treated with curettage. Selective arterial embolization was initially proposed as a preoperative adjuvant to reduce peroperative bleeding. Currently, the role of embolization has been extended to the definitive treatment of aneurysmal bone cyst of the spine in children, as well as to other locations in the skeleton. The authors describe the technique in a 15-year-old girl with a T2 aneurysmal bone cyst. Digital subtraction angiography was performed for tumor vascular mapping, followed by selective arterial embolization with N-butyl 2 cyanoacrylate (NBCA). Because of persistent local pain, repeat embolization was done at 8 months. Pain relief and progressive ossification of the lesion were now observed. At 4-year follow-up, the patient was asymptomatic, with complete ossification of the lesion. Selective arterial embolization (SAE) is a minimally invasive, safe and effective procedure for the permanent occlusion of the pathological feeding vessels of spinal ABC. It should be considered as the treatment of choice for lesions difficult to access with surgery, especially in young patients. Careful pre-embolization vascular mapping of the lesion, operator's experience and use of NBCA are the keys to success.

Preoperative embolization of primary spinal aneurysmal bone cysts by direct percutaneous intralesional injection of n-butyl-2-cyanoacrylate.

Aneurysmal bone cysts (ABCs) are highly vascular lesions often referred for preoperative transarterial embolization. However, accessible arterial pedicles do not always exist. Two cases are presented of pediatric patients with spinal ABCs in which preoperative embolization was performed by percutaneous injection of up to 31 mL of liquid embolic agent (1:7 ratio, n-butyl-2-cyanoacrylate [n-BCA] to ethiodized oil). Total estimated surgical blood loss was 1,000 mL in one case and 3,650 mL in the other case, which occurred during the extensive anterior and posterior approaches required to remove the massive ABCs. Direct percutaneous injection of n-BCA is a technically simple and efficient adjunct to surgical resection with the aim to reduce intraoperative blood loss.

Evolution of an aneurysmal bone cyst: a case report.

The aneurysmal bone cyst (ABC) rarely occurs in the jaws. It represents approximately 1.5% of all non-odontogenic and non-epithelial cysts of the jaws. The literature contains conflicting reports on the clinical and radiological features of ABC of the jaws. The radiographic appearance of ABC varies from a unicystic radiolucency or moth-eaten radiolucency to an extensive multilocular lesion. In this article, we describe the transition of an ABC in the maxillofacial region from a unilocular radiolucent lesion to a radiopaque lesion in a 40-year-old female over a 10-month period, which indicates diversity in the clinical and biologic behavior of ABCs.

Preoperative embolisation in benign bone tumour excision.

PURPOSE: To assess the role of preoperative embolisation in benign bone tumour excision. METHODS: 3 men and 3 women aged 19 to 35 (mean 23) years with either a giant cell tumour or an aneurysmal bone cyst in limb girdle sites underwent preoperative embolisation a day prior to wide local excision by the same surgeon. Tumour size, blood loss, wound healing, infection, and tumour recurrence were assessed. RESULTS: The mean total blood loss was 391 (range, 100-980) ml. No blood transfusion was needed. No patient had any surgery- or embolisation-associated complication. No tumour recurred within a minimum 5-year follow-up. All patients had satisfactory limb function. CONCLUSION: Preoperative embolisation is useful in the management of vascular and aggressive bone tumours located at limb girdle sites where a tourniquet cannot be used.

Aneurysmal bone cysts express vascular markers.

Recently, clonal chromosome abnormalities have been identified in the mural spindle cells in aneurysmal bone cysts (ABCs), but the nature of the cystic spaces is unclear. Endothelial injury has been suggested as a mechanism of aneurysmal formation in these lesions, but few studies have surveyed vascular markers in ABCs. We stained 25 primary aneurysmal bone cysts with a variety of antibodies that stain vessels. Antibody to factor 8 stained the edge of ABC cavities in almost all cases, and antibodies to VEGF-C, GLUT-1, and smooth muscle actin stained the edge of the cavities in approximately half the cases. Antibodies to D2-40 and CD34 also stained the edge of the cavities in some cases. These results suggest that the cavities in ABCs are related to vasculature and support the theory that vascular injury may be important in the pathogenesis of ABCs.

Aneurysmal bone cysts of the pelvis in children: a multicenter study and literature review.

The authors analyzed a series of 15 pelvic aneurysmal bone cysts (9 boys and 6 girls) in children and adolescents who were reviewed with an average follow-up of 50.3 months. Pain and limp were the main symptoms. Four patients had no treatment after the open biopsy. Eleven patients were treated with curettage. Preoperative selective arterial embolization was performed in three cases before curettage. Two recurrences were noted after curettage; recurrences were treated successfully with further curettage. As a result, the authors recommend curettage; more aggressive operative intervention does not appear to be indicated. No major intraoperative vascular complications occurred. Spontaneous healing in a few cases (even in active or aggressive lesions) argues for clinical and radiologic observation after biopsy when possible. In case of a propitious evolution, observation must be continued and surgery might be avoided, but if the lesion increases, treatment must be proposed.

Aneurysmal bone cyst: its pathogenesis based on angiographic, immunohistochemical and electron microscopic studies.

Based on angiographic, immunohistochemical as well as electron microscopic findings, authors outline a hypothesis for the etiopathogenesis of aneurysmal bone cysts. No changes were found at the arterial site in 16 studied aneurysmal bone cysts, with no signs of an arteriovenous shunt. In certain cases, however, dilated and tortous efferent veins became visible in the late venous phase. Due to the impedance of venous flow, the intracystic pressure increases and the small veins become dilated causing formation of aneurysmal slits. This is supported by the immunohistochemical finding that S-actin shows concentric arrangement around the aneurysmal cavities. Endothelial lining and basal membrane remnants were detectable in places, though the aneurysmal slits were devoid of continuous endothelial lining and basal membrane. We suggested that the aneurysmal bone cyst corresponds to a hemodynamic disturbance and is due to primary or secondary venous malformation of the bones.