Overview
Aneurysmal bone cysts (ABCs) are benign, blood-filled lesions characterized by multilocular cysts with thin, fibrous walls, often found in the metaphysis of long bones but can occur in any bone 3.Diagnosis
Histologic confirmation: Typically achieved through surgical biopsy 1.
Imaging: CT and MRI are crucial for delineating cyst characteristics and guiding treatment 1.
Contrast studies: Utilized to assess cyst septation and avoid venous opacification during injection 1.Management
First-line treatment: Direct fibrosing agent injection (e.g., Ethibloc) under CT guidance 1.
Injection technique: Requires general anesthesia, precise needle placement (14-16 gauge), and obliteration of intraosseous needle tracks with histoacryl 1.
Adjunctive treatments: Surgical excision may be necessary for complications like fistulization or recurrence 1.Special Populations
Pediatrics: Direct fibrosing agent injection is used but carries risks such as pulmonary embolism and early aseptic fistulization 1.
Rarity in specific locations: ABCs of the patella are exceptionally rare, with limited case reports 2.Key Recommendations
Use direct fibrosing agent injection under CT guidance for treatment, particularly in pediatric patients, with careful monitoring for complications like pulmonary embolism and fistulization (Evidence: Moderate 1).
Ensure meticulous technique including contrast verification and needle track obliteration to minimize complications (Evidence: Moderate 1).
Consider surgical excision for cases complicated by fistulization or treatment failure (Evidence: Expert opinion 1).References
1 Topouchian V, Mazda K, Hamze B, Laredo JD, Penneçot GF. Aneurysmal bone cysts in children: complications of fibrosing agent injection. Radiology 2004. link
2 Mapelli S, Giraldi A. Aneurysmal bone cyst of the patella. Italian journal of orthopaedics and traumatology 1984. link
3 Chari PR, Reddy CR. Aneurysmal bone cysts. The Australian and New Zealand journal of surgery 1976. link