A Clinicopathological Study on Nine Cases of Osteoid Osteoma

A clinicopathological study on nine cases of osteoid osteoma was performed. All cases had a nocturnal pain, spontaneous pain and severe tenderness, and only two cases had motion pain. Nocturnal pain was not necessarily the first symptom of the onset of the 6.25 months after the onset of other symptoms.Histologically, the cases were classified into initial, intermediate and mature stages. A correlation was found between the duration from the onset of nocturnal pain to operation and the histological stages.Characteristic histological findings of our cases were dilatations of arteries and veins in nidus and surrounding tissue, and nerve fibers on the periosteum of the sclelotic bone of nidus.The clinical features of osteoid osteoma seemed to depend on the presence of the nerve fibers which are sensitive to changes in vascular pressure.