Osteoblastoma is the osteogenic fibroma of the bone which is vascular, benign, and bone-forming skeletal neoplasm.
Histologically, Osteoblastoma resembles the nidus of Osteoid Osteoma but lacks reactive sclerosis.
It accompanies 1 % of all primary bone tumors and 3 % of benign bone tumors.
Generally, it is > 2 cm in diameter.
Site
The spine is the most common site; posterior elements in the neural arch (1/3rd of cases is seen)
Also found in the metaphyseal and diaphyseal regions of long bone.
Clinical Features
Pain is present which is not nocturnal or relieved by NSAIDs as seen in Osteoid Osteoma.
In Spinal Involvement, Scoliosis/ Painful scoliosis with/ without neurological symptoms presents as radiculopathy, paresthesia, and sensory and motor weakness.
Radiological Features of Osteoblastoma
Radiolucent or mottled appearance (Not lytic lesion)
Well- circumscribed lesion
A variable amount of central ossification
The thin peripheral shell of reactive bone
In Spine:
- Enlargement of the lamina, pedicle, or transverse process may be with/ without extraosseous soft tissue mass (May be confused with malignancy)
Bone Scintigraphy shows intense tracer uptake at the site of the lesion.
Pathology
Haphazardly arranged woven or trabecular bone with plump osteoblast and vascular stroma
It is similar to osteoid osteoma.
Treatment of Osteoblastoma
Surgery is the mainstay of treatment
Complete removal is done by Intralesional curettage or en-bloc excision
Neurological deficiency due to intraspinal compression where decompression laminectomy is done.
In inaccessible cases, the tumor re-ossifies where cobalt therapy with moderate doses is tried (avoid radiation).
See also: CHONDROBLASTOMA
See also: Radiograph of Bone Tumor
