Benign bone tumors are noncancerous bone growths, which most commonly occur in the long bones of the arms and legs. Benign tumor types include chondroblastomas, chondromyxoid fibromas, enchondromas, giant cell tumors, nonossifying fibromas, osteoblastomas, osteochondromas, osteoid osteomas and periosteal chondromas. These tumors most commonly occur in late childhood through early adulthood. Symptoms vary by tumor type and location. It is important to distinguish benign bone tumors from cancerous tumors, which may be life threatening.
Bone Lumps and Deformities
Cedars-Sinai Medical Center reports that a visible lump or a lump felt along the length of a bone may be the presenting symptom of a benign bone tumor. Large tumors and those in certain locations may cause bone deformities. For example, an osteoid osteoma in one of the vertebra may cause painful spinal curvature.
Bone pain is a common symptom of certain types of benign bone tumors. “Wheeless' Textbook of Orthopaedics” notes that pain often occurs with chondroblastomas, chondromyxoid fibromas, giant cell tumors, osteoid osteomas and periosteal chondromas. Osteoid osteomas characteristically produce pain that is worst at night. Giant cell tumors can erode through the bone and extend into the joint space, causing joint pain and stiffness. Notably, benign bone tumors sometimes lead to pathological fractures, bone breaks that occur due to structural weakness associated with the tumor. Sudden pain and swelling may occur due to a pathological fracture.
Numbness and Tingling
A benign bone tumor growing near a nerve may impinge on the nerve, causing numbness or tingling beyond the site of the tumor. The American Academy of Orthopaedic Surgeons notes that osteochondromas located behind the knee can precipitate this symptom in the lower leg. Bone tumors in other sites may cause similar symptoms.
Changing Skin Color
Bone tumors growing near a large blood vessel may impinge on the vessel when the limb is in certain positions, notes the American Academy of Orthopaedic Surgeons. This can cause transient, position-dependent changes in skin color. The limb typically becomes pale when the tumor obstructs arterial blood flow. With repositioning and reestablishment of normal blood flow, the affected limb typically turns bright red. Partial blockage of a large vein may cause purplish discoloration of the skin, which disappears when normal blood flow resumes.
Limb Length Discrepancy
Several types of benign bone tumors arise in the metaphysis, the area of the bone that grows during childhood and adolescence. “The Merck Manual for Healthcare Professionals” explains that the presence of a benign tumor sometimes causes overgrowth of the metaphysis, leading to the bone on the affected side growing longer than the matching bone on the other side of the body. This symptom is termed limb length discrepancy. Osteoid osteoma, which most commonly occurs in the long bones of the upper leg and arm, can lead to limb length discrepancy.