Aneurysmal bone cyst of clivus and C1 C2: case report and review of literature.

Aneurysmal bone cyst are benign rapidly expanding bone destructive lesions of any bone. They are common in the metaphysis of long bones but 10-30% involve the spine. Cervical region involvement is uncommon. We report a case of aneurysmal bone cyst of clivus C1 and C2 with minimum symptoms. Involvement of C1 and clivus separately had been reported in past, but simultaneous involvement of both is presented in this report for the very first time.