Overview

Bone tumours in children, though rare, can cause concern. Osteoblastoma, a benign bone tumour, can affect children of all ages. While uncommon, it's crucial to be aware of its potential presentation. This article will provide you with a comprehensive review of osteoblastoma in children, discussing its presentation, diagnosis, and treatment options. By understanding this condition, you can play an active role in your child's health and ensure they receive appropriate care.

What is osteoblastoma?

Osteoblastoma is a rare type of benign bone tumour. It develops when healthy bone tissue is broken down and replaced with a weaker, abnormal tissue called osteoid. This osteoid material builds up around the healthy bone, making it more susceptible to fractures. While osteoblastoma can occur anywhere in the body, it most commonly affects the spine, hands, or legs. The tumour's growth can cause pain, swelling, and muscle spasms in the affected area.¹

How rare is osteoblastoma?

Osteoblastomas account for less than 1% of all primary bone tumours. This means that out of every 100 bone tumours, statistically less than 1 will be an osteoblastoma. They are diagnosed most often in people between their teenage years and thirties, with males being about twice as likely to develop them compared to females.²

The exact cause of osteoblastoma is unknown.

Clinical presentation

Osteoblastoma often presents with distinct symptoms.^3,4 

Common symptoms

• The most common symptom is persistent pain, typically worsening over time. Pain from osteoblastoma may not respond well to common pain relievers like ibuprofen or acetaminophen as some other bone tumours
• Swelling and tenderness: the affected region may get swollen and tender to the touch

Location-specific symptoms

• Hands and feet: when osteoblastoma affects the hands or feet, swelling and pain are the primary concerns. The pain often intensifies at night, disrupting sleep¹
• Spine: if the tumour develops in the spine, additional symptoms can arise due to nerve compression. These symptoms involve back pain, muscle spasms, numbness, movement limitations, and even scoliosis, a curvature of the spine¹

Diagnostic workup

Osteoblastoma requires a combination of tests for accurate diagnosis.^2,3,4

History and physical examination

The doctor will first gather information about your medical history, including symptoms, duration, and location of pain. A physical exam will evaluate the affected region for swelling, tenderness, and movement restrictions.

Imaging studies

• X-ray: this provides basic images of bones and can reveal abnormalities like lesions or fractures
• CT Scan (Computed Tomography): this advanced imaging creates detailed cross-sectional images, allowing for better visualisation of the tumour's size and location, especially in the spine
• MRI (Magnetic Resonance Imaging): produces detailed images of soft tissues and bones. It can help identify the extent of the tumour and its impact on surrounding nerves or tissues

Other tests to consider

• Bone scan: this test uses radioactive tracers to identify areas of increased bone activity, which may indicate a tumour
• Blood tests: a full blood count (FBC) is performed to assess overall health and rule out other conditions
• Biopsy: a needle biopsy involves taking a small tissue sample from the tumour using a thin needle. It is then examined under a microscope to confirm the presence and type of osteoblastoma

Diagnostic criteria

While the previous section explored the diagnostic steps for osteoblastoma, there are specific criteria used for definitive diagnosis according to the World Health Organization (WHO) classification system.²

For a tumour to be classified as osteoblastoma, it must meet these key criteria:

• Lytic bone tumour> 2 cm: imaging tests (X-ray, CT scan, MRI) must reveal a clear area of bone destruction (lytic lesion) larger than 2 centimetres
• Well-defined tumour borders: the edges of the tumour on imaging should be distinct and well-demarcated, separating it from the healthy bone
• No permeation of host bone: there should be no evidence of the tumour infiltrating or spreading into the surrounding healthy bone tissue
• Histological confirmation: a biopsy, where a small tissue sample is extracted and examined under a microscope, is crucial. The microscopic examination should reveal specific features:
  • Bone-forming tumour: the tissue sample should show evidence of bone formation
  • Trabeculae of remodelled woven bone: the newly formed bone should appear as a network of thin strands (trabeculae) made of remodelled woven bone
  • Plump osteoblasts: these are the bone-forming cells and should be abundant and plump in appearance
  • Vascularised background: the tissue should be well-supplied with blood vessels

Treatment options

Careful treatment planning includes the following:^2,3,4

Surgery: this is the mainstay of treatment for osteoblastoma. The surgical procedure depends on the tumour size, site, and severity.

Types of Surgery

• Intralesional curettage: this involves scraping out the tumour tissue using a specialised instrument called a curette. This procedure aims for the complete removal of the tumour while preserving healthy bone
• Intraoperative adjuvants: these techniques are sometimes combined with curettage to destroy any microscopic tumour cells left behind. Examples include:
  • Cryotherapy: freezing the tumour with liquid nitrogen
  • Phenol: it is a chemical agent that destroys tumour cells
  • Cauterisation: burning the tumour bed with heat
• Bone grafting: after removing the tumour, the resulting cavity may be filled with bone graft material to promote healing and maintain bone structure. This graft material can be synthetic, donated bone (allograft), or bone harvested from another part of the patient's body (autograft)
• En Bloc resection: if the tumour is large, aggressive, or located in a critical area, complete removal with surrounding healthy tissue (en bloc) might be necessary. This may involve internal fixation with pins or plates to restore bone stability

Other treatment considerations

Pre-operative embolization: in some cases, blocking blood flow to the tumour before surgery can minimise bleeding during the procedure. However, this needs to be performed very close to surgery to prevent the blood supply from re-establishing itself.

Percutaneous ablation: this emerging technique uses minimally invasive methods, like radiofrequency ablation, to destroy the tumour with heat. While still under development, it offers a potential alternative to surgery in specific cases.

Prognosis

Majority of osteoblastoma cases can be successfully treated, leading to positive long-term outcomes. However, individual prognosis may differ based on various factors.³

Factors influencing prognosis

• Tumour activity: the aggressiveness of the tumour plays a role. More active tumours may require more extensive treatment and carry a slightly higher risk of recurrence
• Treatment response: how well the tumour responds to the chosen treatment (surgery, etc.) impacts the overall outcome
• Age and health: a child's age and general health at the time of diagnosis can influence the treatment approach and overall prognosis
• Tolerance for treatment: a child's ability to tolerate specific medications, procedures, or therapies can factor into treatment decisions and recovery

Risk of recurrence

While rare, there is a possibility (around 23%) that osteoblastoma may recur after treatment.² This emphasises the importance of regular follow-up care with your doctor to monitor for any signs of recurrence and ensure long-term well-being.

Summary

Osteoblastoma, a rare benign bone tumour, can affect children, causing persistent pain, swelling, and movement limitations. While concerning, early diagnosis through imaging tests and biopsies leads to effective treatment, typically surgery. The prognosis for children with osteoblastoma is generally positive, with regular follow-up crucial for monitoring. If you have any concerns about your child's health, consult a healthcare professional for personalised advice.

FAQs

Is osteoblastoma serious?

While osteoblastoma is a tumour, it's classified as benign (non-cancerous). However, it can cause significant pain and disrupt daily activities. Early diagnosis and treatment are important to prevent complications and ensure a smooth recovery.

Can my child play sports if they have osteoblastoma?

Participation in sports typically depends on the location and size of the tumour.  During treatment, especially after surgery, your child's doctor will advise on activity restrictions to promote healing. Once recovered, sports participation might be possible with modifications or limitations depending on the affected bone and the doctor's recommendations.

What are the risks of surgery for osteoblastoma?

As with any surgery, there are potential risks associated with removing osteoblastoma. Potential risks may involve infection, bleeding, nerve damage, and damage to surrounding tissues. However, advancements in surgical techniques minimize these risks. Discussing the specific risks and benefits of surgery with your child's doctor is crucial.

How long will my child stay in the hospital after the operation?

The hospital stay period depends on the difficulty of the surgery. In some cases, your child might be able to go home the same day, while others might require an overnight stay for monitoring. Your doctor will provide a specific timeframe based on the procedure performed.

Will my child need physical therapy after surgery?

Physical therapy can be beneficial in regaining strength, flexibility, and range of motion in the affected area after surgery. Your child's doctor will decide if physical therapy is needed and start a personalized rehabilitation plan.

Can osteoblastoma affect a child's growth?

If the tumour is located near a growth plate (the area where bones grow longer), it's possible that it could affect bone growth. Early diagnosis and treatment are crucial to minimize any potential impact on growth.