Giant bone island of femur. Case report, literature review, and its distinction from low grade osteosarcoma.

A 42-year old male with the largest reported giant bone island (10.5 cm in length) is presented. Due to its ominous size, association with some degree of pain and increased uptake on radionuclide bone scan, a biopsy was considered necessary definitively to rule out a slow-growing osteosarcoma or blastic metastasis. Documentation of growth in adult patients of conventional and giant bone islands, coupled with evidence of increased radionuclide uptake, makes the clinicoradiological distinction between bone islands and blastic malignancies difficult. Guidelines for biopsy versus serial radiographic follow-up of such lesions are addressed.