A growth of normal cells in an abnormal location forms a benign tumor. Cells that grow abnormally are a malignant tumor or cancer. There are many different benign tumors that occur in the growing skeleton. They vary in the locations where they grow and in the different contents of the lesions. There is a unique bone tumor that occurs in a child's growing skeleton called a simple bone cyst, also known as a solitary or unicameral bone cyst.
Cysts are fluid-filled cavities.
When these cysts occur in a bone they cause a weakness in that bone, enabling even minor injuries to result in a break. These breaks can be difficult to heal and often result in a deformity of the limb. Such breaks can even cause part of the growing area of the bone to stop growing. Most of these tumors are brought to a physician's attention because the bone has broken at the tumor site. These frequent fractures of weakened bone disrupt childhood and can interfere with normal activities.