[5][6] The afflicted may have relatively small amounts of pain that will quickly increase in severity over a time period of 6–12 weeks.

The skin temperature around the bone may increase, a bony swelling may be evident, and movement may be restricted in adjacent joints.

[citation needed] Commonly affected sites are metaphyses of vertebra, flat bones, femur and tibia.

[8] Approximate percentages by sites are as shown:[citation needed] Aneurysmal bone cyst has been widely regarded a reactive process of uncertain cause since its initial description by Jaffe and Lichtenstein in 1942.

Many hypotheses have been proposed to explain the cause and pathogenesis of aneurysmal bone cyst, and until very recently the most commonly accepted idea was that aneurysmal bone cyst was the consequence of an increased venous pressure and resultant dilation and rupture of the local vascular network.

An aneurysmal bone cyst can arise from a pre-existing chondroblastoma, a chondromyxoid fibroma, an osteoblastoma, a giant cell tumor, or fibrous dysplasia.

[citation needed] X-ray and CT scan show lytic expansion lesions with clear borders.

[1][11] Following conditions are excluded before diagnosis can be confirmed:[12] Curettage is performed on some people,[13] and is sufficient for inactive lesions.

Liquid nitrogen, phenol, methyl methacrylate are considered for use to kill cells at margins of resected cyst.