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Health condition

Chondroblastoma

Chondroblastoma is a rare benign cartilage tumour with a distinctive address: the epiphysis - the very end of a growing bone next to the joint - in teenagers and young adults, causing joint-like pain that is easily attributed to sport; treatment is specialist curettage.

Why trust this guide

  • 01

    Editorial team

    Written by our editorial team from the UK sources listed on each page.

  • 02

    Sourced from guidance

    Checked against current NHS and UK specialist society guidance at the time of review.

  • 03

    Current for 2026

    Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.

Key facts

The essentials at a glance.

The symptoms to recognise, when to seek help, which specialist to see, and what treatment usually involves.

  • Classic presentation: months of progressive knee, hip or shoulder pain in a teenager, often with a joint effusion and reduced range - frequently misdiagnosed as a sports injury

  • Imaging signature: a small, well-defined lytic lesion in the epiphysis of a skeletally immature patient, with fine calcification and marked surrounding marrow oedema on MRI

  • Histology shows characteristic chondroblasts with "chicken-wire" calcification; the tumour carries an H3F3B mutation distinguishing it from mimics

  • Treatment is curettage with adjuvants and grafting, done carefully to protect the growth plate and joint surface; recurrence affects a minority and late benign lung deposits are rare but documented

Understanding the condition

What it is and what happens next.

What causes it, how it is diagnosed, and the treatment routes available in the UK.

What it is and how it feels

Few bone lesions choose the epiphysis, so location does much of the diagnostic work - yet precisely because the pain is at the joint in a sporty age group, the average chondroblastoma story includes months of physiotherapy for a presumed soft-tissue injury before anyone X-rays the bone. The lesion sits millimetres from articular cartilage and often abuts the growth plate, which raises the surgical stakes: incomplete removal risks recurrence, over-aggressive removal risks the joint surface or growth arrest.

Diagnosis and treatment routes

Referral to a bone tumour service brings the required blend: diagnostic confirmation (imaging review and biopsy where appearances are not classic), then image-guided or open curettage with high-speed burring, adjuvants and grafting, executed around the physis and subchondral plate - radiofrequency ablation is an option for small, favourably placed lesions. Follow-up imaging for two to three years watches for local recurrence (re-treatable in most), and the rare pulmonary deposits behave indolently and are managed surgically. In much of the UK, a routine NHS referral to the relevant specialist clinic can take several months, whereas an initial appointment with a private consultant is typically available within around two weeks.

Seeing a specialist

Who to see, and how quickly you can be seen.

The specialist for this condition is usually a specialist bone tumour unit (sarcoma centre). Your GP can refer you on the NHS, or you can arrange a private consultation directly.

A quiet reminder

This guide is for information, not medical advice.

Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any of the emergency symptoms described above.

Frequently asked

Common questions about Chondroblastoma.

Quick, plain-English answers to what people ask us most.

  • What is chondroblastoma?

    Chondroblastoma is a rare, generally benign (non-cancerous) bone tumor made up of cartilage-forming cells, most commonly developing at the ends of long bones near a joint, particularly around the knee, hip or shoulder in adolescents and young adults. Although benign, it can cause significant local bone damage if left untreated. It typically requires surgical treatment rather than resolving on its own.

  • What causes chondroblastoma?

    The exact cause is not fully understood, but it arises from an abnormal growth of cartilage-forming cells within the bone, often at the growth plate area in younger patients. It is not linked to any known lifestyle or environmental cause. It occurs sporadically without a clear inherited pattern in most cases.

  • What symptoms does it cause?

    Common symptoms include localised joint or bone pain, often worsening over weeks to months, sometimes with swelling and reduced range of motion in the nearby joint if the tumor is close to a joint surface. Symptoms can sometimes mimic other joint problems, occasionally leading to a delay in diagnosis. Persistent unexplained joint pain in a young person, particularly around the knee, warrants imaging assessment.

  • Is chondroblastoma dangerous?

    While it is benign and does not spread like cancer, it can cause significant local damage to the bone and nearby joint surface if left untreated, and can occasionally recur after treatment. Very rarely, it can spread to the lungs despite being classified as benign, though this is uncommon. With appropriate surgical treatment, the outlook is generally very good.

  • How is chondroblastoma treated?

    Treatment is surgical, typically involving curettage (scraping out the tumor) and filling the resulting cavity with bone graft material, aiming to preserve the joint surface and function as much as possible. Because it is near a growth plate in younger patients, careful surgical planning helps minimise any impact on future bone growth. Regular follow-up imaging monitors for the possibility of recurrence.

  • What is the outlook after treatment?

    The outlook is generally good, with most people recovering well and regaining good joint function after surgery, though regular follow-up is recommended given a moderate risk of local recurrence, particularly in the first few years. Recurrence, if it happens, is usually treated successfully with further surgery. Long-term joint health depends partly on how much the joint surface was affected before treatment.

  • When should I see a specialist?

    See a doctor if you have persistent, unexplained joint or bone pain, particularly around the knee, hip or shoulder in a young person, as imaging is needed to investigate the cause. NHS orthopaedic or bone tumor referral can take several weeks; a private orthopaedic consultation is typically available within about 2 weeks for earlier assessment.