Osteoid Osteoma: Symptoms, Diagnosis, Treatment
Osteoid osteoma facts:
- Osteoid means non-ossifying bone (ground substance of the bone without calcification or ossification)
- This is a benign tumour, unlike osteosarcoma
- Lesion is well circumscribed
- Arises mostly in the cortex of long bones, occasionally in the cancellous bones of the spine.
- Three times commoner in male
- Occurs mainly at the age between 10-35 years.
Pathology of osteoid osteoma:
In osteoid osteoma, there is formation of a small tumour that has small pinhead like nidus of osteoid tissue. Size of nidus is usually less than 0.5 cm diameter.
Symptoms of osteoid osteoma:
- Severe increasing pain.
- Pain is well-localised, deep aching.
- Pain is worse at night
- This pain is eased by NSAIDs.
- Usually no swelling.
Diagnosis of osteoid osteoma:
X ray in osteoid osteoma:
Plain radiographs typically show a tiny osteolytic lesion usually in metaphyseal region and surrounded by a hollow of sclerosis which is called nidus (origin of tumour) of tumour.
CT scan in osteoid osteoma:
The nidus can be seen very well on a fine cut CT scan.
Isotope bone scan in osteoid osteoma:
The lesion exhibits intense uptake on an isotope bone scan.
Treatment of osteoid osteoma:
For relieving pain, NSAID is given. Pain of osteoid osteoma does not subsides in opoid anaelgesics, whereas, aspirin (NSAID) works well.
For curative purpose, surgery is the treatment of choice. But in some younger patients osteoid osteoma may resolve spontaneously after several months. But most require surgery. The nidus is excised and curettage is done. Nidus contains fibous tissue. Removal of the central nidus results in resolution of the reactive bone formation and dramatic relief of symptoms. Some less invasive procedures can be used, it needs necessary equipment. A CT guided needle can be inserted into the nidus and the lesion ablated with radiofrequency coagulation.