Bone island (enostosis): clinical significance and radiologic and pathologic correlations

This study was undertaken to explain the increased scintigraphic activity of some bone islands by correlating the clinical, radiographic, scintigraphic, and histopathologic findings. The material for the study consisted of six patients with bone islands who had undergone histopathologic examinations of the lesions. Based on histopathologic-radiologic correlations, we postulate that the osteoblastic activity of a bone island makes it appear "hot" on scintigraphy, although other factors such as the size of the lesion may play some role in this phenomenon. In addition, we tried to find a logical algorithm for the radiologic evaluation and management of sclerotic lesions that look like bone islands but exhibit increased uptake of radiopharmaceuticals on bone scan examination. We emphasize that the morphology of the lesion, as demonstrated on the radiologic examination, rather than its degree of activity on the bone scan is a guide to the correct diagnosis.