What are other benign primitive bone tumors?

➢ Angioma ➢ Essential bone cyst ➢ Aneurysmal Bone Cyst : Generally occurs during the first 2 decades of life / no sex predilection Most frequently develops in the metaphysis of long bones and the posterior elements of vertebral bodies. Microscopy : ✓ Consists of multiple blood-filled cystic spaces separated by thin, tan-white septae. ✓ The septae are composed of plump uniform fibroblasts, multinucleated osteoclast-like giant cells, and reactive woven bone, but they are not covered by endothelium ✓ Recure rarely after resection ✓ Rarely behaves agressively