Aneurysmal Bone Cyst (ABC)
A benign but locally aggressive bone lesion made up of blood-filled spaces. With modern, minimally-invasive treatment, most patients heal completely and return to full activity.
What is an Aneurysmal Bone Cyst?
Aneurysmal Bone Cyst (ABC) is a benign (non-cancerous) but locally aggressive bone lesion made up of blood-filled spaces separated by thin tissue walls. Despite being non-cancerous, it can grow aggressively and weaken bone structure.1
Who gets ABC and where does it occur?
Most common, but can occur at any age
Affects males and females equally
Metaphysis & epiphysis; spine, pelvis & small bones less common
Spine and pelvis lesions tend to be larger when they do occur.2
What causes ABC?
The exact cause is unknown. It may be related to previous trauma in some cases, and can occur as a primary tumour or as a secondary change in other bone tumours such as:
- • Giant cell tumour
- • Chondroblastoma
- • Fibrous dysplasia
- • Osteosarcoma and chondrosarcoma
What are the symptoms of ABC?
How is ABC diagnosed?
- • X-rays show an expanded cystic lesion with thin 'eggshell' borders and a classic 'soap bubble' appearance
- • MRI is essential and shows characteristic multiple fluid-fluid levels inside the lesion
- • CT scans may be used in selected cases
- • Needle biopsy is mandatory to confirm diagnosis — ABC can mimic other bone tumours
- • Pathology shows blood-filled spaces with giant cells and spindle cells
Understanding Aneurysmal Bone Cyst — video explainer
Current treatment options for ABC
Treatment has evolved significantly, with a clear shift toward minimally-invasive approaches.3
Minimally Invasive Treatments (now preferred)
- • Polidocanol sclerotherapy — complete healing in modern studies
- • Radio-opaque gelified ethanol — newer technique, excellent safety profile
- • Outpatient, faster recovery, fewer complications
- • Usually 2–3 sessions over several months; average healing time ~5 months
- • Small (~1 cm) incision with specialised instruments
- • Combined with bone grafting
- • Complete healing typically within 6 months
Traditional Surgical Treatment
- • Extended curettage with bone grafting
- • Adjuvants such as high-speed burring or chemical treatment (phenol)
- • Reserved for larger, more aggressive lesions or when minimally-invasive options fail
Advanced Treatment Options
- • Arterial embolization (blocking blood vessels feeding the cyst)
- • Combination therapies using multiple approaches
- • En-bloc resection (complete removal) only in severe cases
- • Denosumab: can shrink ABCs, but caution in children due to risk of dangerous calcium changes
- • Zoledronic acid: alternative with encouraging results
Does ABC come back after treatment?
- • Age: children ≤12 years have higher recurrence risk
- • Location: ABCs near growth plates (juxtaphyseal) recur more often
- • Size & aggressiveness: larger, more aggressive lesions are more likely to recur
What's the outlook with ABC?
ABC does not spread to other parts of the body and is not life-threatening. Modern treatments show very high success rates and most patients return to full activity within 6 months. Long-term monitoring is important, especially in younger patients.5
Which treatment is best for me?
- • First-time ABC diagnosis
- • Lesion in an accessible location
- • Patient prefers a minimally-invasive approach
- • Medical conditions make open surgery risky
- • Very large or aggressive ABC
- • Previous treatment has failed
- • Significant bone destruction has occurred
- • Anatomical location requires an open approach
When should I contact my doctor?
- • Sudden severe pain or suspected fracture
- • Rapid increase in swelling
- • New neurological symptoms (numbness, weakness)
- • Any concerns about changes in your ABC
- • Regular monitoring is essential, especially in the first 2 years
- • Return to activities should be guided by your doctor
- • Report any new symptoms promptly
References
- 1Healthcare Bulletin – Radiological Evaluation of ABC Management with Sclerotherapy, 2024
- 2NCBI PMC – ABC Recurrence at Juxtaphyseal Locations, 2024
- 3Wiley Online Library – Minimally Invasive Curettage and Allogenic Bone Grafting, 2022
- 4PubMed – Radio-opaque Gelified Ethanol Sclerotherapy for ABC, 2025
- 5NCBI PMC – Modern Treatment of Unicameral and Aneurysmatic Bone Cysts, 2024
- 6Orthopedic Reviews – Current Strategies for ABC Treatment, 2022
Important Notice: This information is provided for educational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. The content on this page should not be used for diagnosing or treating a health condition or disease, and is not a replacement for professional medical care.
Always seek the advice of a qualified orthopaedic oncologist, physician, or other healthcare provider with any questions you may have regarding aneurysmal bone cyst or any other medical condition. Never disregard professional medical advice or delay in seeking it because of information you have read on this website.
Treatment recommendations vary significantly based on factors including ABC location, size, aggressiveness, patient age, and individual circumstances. Only a qualified specialist can provide personalised medical advice and determine the most appropriate treatment approach for your specific situation.
In case of emergency or urgent symptoms such as severe pain, suspected fracture, or neurological changes, seek immediate medical attention or contact your local emergency services.
The Orthoncology Clinic is committed to providing current, evidence-based information while emphasising the importance of professional medical consultation for all health-related decisions.