Osteoblastoma

A rare, benign bone tumor

Osteoblastoma

High magnification of osteoblastoma showing characteristic features.

Osteoblastoma is a rare, benign bone tumor that primarily affects the spine and long bones. It is characterized by the proliferation of osteoblasts, which are cells responsible for bone formation. Osteoblastoma is similar to osteoid osteoma, but it is larger and tends to cause more aggressive symptoms.

Epidemiology

Osteoblastoma accounts for approximately 1% of all primary bone tumors. It is most commonly diagnosed in adolescents and young adults, with a higher prevalence in males compared to females.

Pathophysiology

Osteoblastoma arises from the osteoblasts, which produce osteoid and woven bone. The tumor is typically well-circumscribed and can vary in size. Unlike osteoid osteoma, osteoblastoma can grow larger than 2 cm in diameter and may cause significant bone pain and swelling.

Clinical Presentation

Patients with osteoblastoma often present with localized pain that may worsen at night. The pain is typically less responsive to nonsteroidal anti-inflammatory drugs (NSAIDs) compared to osteoid osteoma. Other symptoms may include swelling, tenderness, and neurological deficits if the tumor is located in the spine.

Diagnosis

The diagnosis of osteoblastoma is based on clinical evaluation, imaging studies, and histological examination. X-ray and computed tomography (CT) are commonly used to assess the size and location of the tumor. Magnetic resonance imaging (MRI) can provide additional information about the involvement of surrounding soft tissues.

Histology

Histologically, osteoblastoma is characterized by the presence of numerous osteoblasts surrounding trabeculae of osteoid and woven bone. The tumor may also contain giant cells and areas of hemorrhage.

Treatment

The primary treatment for osteoblastoma is surgical resection. Complete removal of the tumor is necessary to prevent recurrence. In some cases, curettage and bone grafting may be performed. Radiation therapy is generally avoided due to the risk of malignant transformation.

Prognosis

The prognosis for patients with osteoblastoma is generally favorable following complete surgical resection. However, recurrence can occur if the tumor is not entirely removed. Malignant transformation to osteosarcoma is rare but has been reported.

Related pages

• Osteoid osteoma
• Osteosarcoma
• Bone tumor
• Osteoblast