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What is Secondary aneurysmal bone cyst arises in - and explain in detail?
Most of the time (80%) aneurysmal bone cyst is primary, and no other pathology is found.
Secondary aneurysmal bone cysts (20%) occurs when bone changes of aneurysmal bone cyst occur in a pre-existing lesion:-


Giant cell tumors (osteoclastoma) : - Most common      
Osteoblastoma 
Simple bone cyst
Non-ossifying fibroma  
Telangiectatic osteosarcoma
Metastasis
Fibrous dysplasia
Paget's disease
 Chondromyxoid fibroma
Chondroblastoma