Case of solitary aneurysmal bone cyst of the axis (C2) presenting with pathological odontoid fracture

Background: Aneurysmal bone cysts (ABCs) rarely involve the cervical spine, and isolated lesions of the axis (C2) in adults are exceptionally uncommon. As C2 is critical in maintaining craniocervical stability, destructive lesions may lead to pathological fractures. Case Description: A 48-year-old female presented with mechanical cervical pain due to a pathological type II odontoid fracture attributed to a solitary C2 ABC. To address instability, the patient underwent a posterior C1– C3 fusion. Here, we also reviewed six similar isolated C2 ABCs in adults, with treatments ranging from medical therapy to vertebroplasty, intralesional therapy, and resection with fusion. Conclusion: ABCs involving the C2 vertebral body present significant biomechanical challenges. In the presence of fracture-related instability, posterior fixation is both safe and effective.