Bone Island
Bone islands are commonly found bone lesions on imaging studies. Bone islands are benign and non cancerous. Bone islands are lesions which are composed of dense bone within another bone in your body. Bone islands almost never cause symptoms and are left alone. The main concern is that they can look like bone tumors or spread of cancer from somewhere else.
What is a bone island?
A bone island is cortical bone found along the surface of the bone located within the shaft or central cavity of the bone.
What does a bone island look like on X-ray and CT?
A bone island is a dense white lesion that may be round or oval. The margins may have radiating spicules. Bone islands can range up to about 2 centimeters in size or even larger. There can be one or multiple bone islands.
What do bone islands look like on MRI?
Bone islands are dark on all the sequences. They show no surrounding edema or enhancement after giving contrast. This distinguishes bone islands from more aggressive lesions like cancerous tumors.
What do bone islands look like on nuclear medicine bone scan?
They usually show mild or no uptake. This is helpful to differentiate bone islands from more aggressive lesions that may look like bone islands.
Are bone islands cancerous?
No. Bone islands are benign lesions. They may be confused for more aggressive lesions like cancer.
What are the symptoms of bone islands?
Bone islands usually have no symptoms. In rare cases, they may cause pain. The presence of symptoms like pain should prompt more testing to exclude more aggressive lesions.
Who gets bone islands?
Anyone can have a bone island but they are more common in adults.
What causes bone islands?
It is not known. Some people may have them at birth while they may develop in others. Bone islands can have slow growth.
What else can look like a bone island?
A bone island can have a similar appearance to benign and cancerous bone tumors and metastasis (spread of cancer to the bone).
Where are bone islands most common?
The pelvis, long bones and ribs are common sites although they can occur anywhere in the skeleton.
How are bone islands treated?
They are usually not treated and left alone.
What can be done to make sure the bone island is not something else?
Additional testing with CT, MRI and bone scan can confirm the diagnosis of a bone island. Sometimes follow up may be needed. In rare cases, a biopsy may be indicated, particularly when they grow rapidly.
Bone island: summary
Bone islands are benign bone lesions that are sclerotic or white in appearance. They are islands of dense white bone in the shafts or central cavity of bone.
They usually cause no symptoms and require no treatment. They are often found incidentally on imaging tests done for other reasons.
Most of the time, they are diagnosed confidently. If there is doubt about the diagnosis, further testing may be needed. In rare cases, biopsy is indicated for fast growing bone islands.