Giant bone islands: a case with 31 years of follow-up.

A dense bone lesion raises immediate concern about the possibility of a primary or secondary tumor. Stability of the image over time is a strong argument against a malignancy. Benign solitary bone islands are usually believed to remain stable over time, with no tendency toward growth. We report a case in a patient with 31 years of follow-up, during which marked growth of the island was documented. The bone scan was normal, and histology established the diagnosis of benign bone island. In a patient with an enlarging sclerotic lesion, typical radiographic features and absence of radionuclide uptake are strong arguments in favor of a bone island.