Osteoid Osteoma

Osteoid osteoma is a benign, solitary, painful circumscribed osteoblastic bone tumor of spongy bone. It was first identified as a clinical entity by Jaffe in 1935. It has been shown that the tumor nidus in osteoid osteomas contains a concentration of peripheral nerves not seen in other fibro-osseous neoplasms. Jaffe and Lichtenstein have suggested that the lesion is a true neoplasm of osteoblastic derivation, but others have suggested that the lesion occurs as a result of trauma or inflammation. In some instances, it can be confused with osteomyelitis and may actually represent a form of osteomyelitis. The size of osteoid osteoma is <2 cm. Osteoid osteoma and osteoblastoma are closely related benign bone tumors, with osteoid osteoma being under 2 cm and osteoblastoma being larger than 2 cm.