The Orthoncology Clinic — Dr Srimanth B S
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Patient Awareness · Benign Bone Tumours

Osteofibrous Dysplasia & the OFD-like Adamantinoma Spectrum

A rare, benign fibro-osseous lesion of childhood that most often affects the front of the shin bone (tibia), sitting on a spectrum with OFD-like and classic adamantinoma. Careful biopsy and long-term follow-up help distinguish lesions that only need watching from those that need surgery.

Overview

What is osteofibrous dysplasia?

Osteofibrous dysplasia (OFD) is a rare, benign fibro-osseous lesion of bone. It shows woven bone trabeculae rimmed by osteoblasts within a fibrous stroma and most often affects the anterior cortex of the tibia in young children. It typically presents before age 10 and either stabilises or regresses after skeletal maturity.1,4

Key point: OFD is benign, but it needs careful monitoring because it can mimic — or progress along a spectrum into — OFD-like adamantinoma and, rarely, classic adamantinoma.1

The OFD-like adamantinoma spectrum

Classic OFD

Benign childhood lesion that often remodels after growth.

OFD-like adamantinoma

Intermediate lesion with focal epithelial islands on biopsy; behaves more aggressively than classic OFD.

Classic adamantinoma

Low-grade malignancy with prominent epithelial nests; needs wide excision and long-term surveillance.

Who's Affected

Who gets OFD and where does it occur?

Age
2–10 yrs

Classic OFD in early childhood; OFD-like adamantinoma peaks in adolescence

Sex
M > F

Slight male predominance

Common site
Anterior tibia

Front cortex of the shin bone; occasionally fibula

Most children present with a painless or mildly painful shin swelling. Some develop anterior bowing of the tibia leading to a leg-length difference. A pathological fracture after minor injury is uncommon but well described.1,4

Causes

What causes OFD and OFD-like adamantinoma?

The exact cause is unknown. Proposed mechanisms include a developmental error in bone formation, changes after minor trauma, or a genetic predisposition.

Along the spectrum
  • • No known environmental or hereditary risk factors
  • • OFD-like adamantinoma may reflect transformation of OFD over time
  • • Some cases may be early adamantinomas that were undersampled at biopsy

1

Warning Signs

What symptoms should raise concern?

Painless shin swelling
The commonest first sign, often noticed by a parent.
Mild shin pain
Usually low-grade and activity related.
Anterior tibial bowing
Gradual forward bowing of the shin, sometimes with a leg-length difference.
Pathological fracture
Uncommon; occurs after minor injury when the front cortex is weakened.
Red flags suggesting OFD-like or classic adamantinoma
  • • Persistent pain that does not respond to conservative care
  • • Rapid enlargement of a known lesion
  • • Cortical breach or soft-tissue extension on imaging

1,2

Diagnosis

How is OFD diagnosed and told apart from adamantinoma?

Imaging
  • • Plain X-ray: well-defined intracortical lytic lesion in the anterior tibia with a sclerotic rim (OFD); occasional cortical breach suggests OFD-like adamantinoma
  • • MRI: assesses medullary involvement and soft-tissue extension — cortical breach is a red flag
  • • CT: evaluates cortical integrity in detail
  • • Whole-body imaging in selected cases to look for rare metastases
Biopsy & immunohistochemistry
  • • Classic OFD: fibrous stroma with osteoblastic rimming, no epithelial cells
  • • OFD-like adamantinoma: focal epithelial cell nests staining positive for cytokeratins and CD99
  • • Classic adamantinoma: prominent epithelial islands throughout the lesion
  • • Sampling error is a real risk — biopsy is planned with the surgical team to preserve future limb-salvage options
AP and lateral X-rays of the left tibia in a 4-year-old child showing osteofibrous dysplasia — a lytic, intracortical lesion in the anterior mid-diaphysis of the tibia with a sclerotic rim and mild anterior bowing, managed with observation.
X-rays of the left tibia in a 4-year-old child — AP (left) and lateral (right) views showing an intracortical lytic lesion in the anterior mid-diaphysis with a sclerotic rim and mild anterior bowing, consistent with osteofibrous dysplasia and managed with observation. Case followed at The Orthoncology Clinic.
Key point: Accurate biopsy sampling and immunohistochemistry prevent both undertreatment of an unrecognised OFD-like adamantinoma and overtreatment of simple OFD.2
Watch

Understanding benign bone tumours in children

A short explainer on how we approach benign bone lesions like OFD — the role of imaging, when a biopsy is needed and how we decide between observation and surgery.

"Benign bone tumours — what patients need to know" — an introduction to diagnosis, monitoring and treatment principles used at The Orthoncology Clinic.
Watch on YouTube →
Treatment

Current treatment options along the OFD spectrum

Treatment depends on where the lesion sits on the spectrum, the child's age and skeletal maturity, symptoms and any deformity. The overarching aim is the least invasive plan that will reliably control the disease and preserve limb function.1,4

Classic OFD — observation first

  • • Most OFD lesions stabilise or regress after skeletal maturity
  • • Asymptomatic children need no intervention, just monitoring
  • • Bracing or activity modification helps with tibial bowing
  • • Surgery — usually a corrective osteotomy — is reserved for progressive deformity or functional impairment

1,4

OFD-like & classic adamantinoma — wide excision

OFD-like adamantinoma
  • • Wide local excision with negative margins to prevent progression
  • • Limb-salvage reconstruction planned around the child's age and remaining growth
  • • Careful histological review of the whole specimen to exclude classic adamantinoma

1,5

Classic adamantinoma
  • • Radical en bloc resection of the tumour
  • • Reconstruction with a megaprosthesis, allograft or vascularised fibula
  • • Amputation only when the tumour cannot be safely reconstructed

1,3

Reconstruction after tibial resection

  • • Custom tibial endoprosthesis with soft-tissue flap coverage
  • • Allograft or allograft-prosthesis composite for diaphyseal defects

3

  • • Vascularised fibula graft in children for long-term biological integration
  • • Expandable prosthesis in growing patients to preserve leg length

3,5

A carefully planned biopsy is central to deciding between observation and surgery, and limb-salvage principles guide reconstruction so that leg length, growth and function are all preserved.

Patient example. A 12-year-old boy with OFD-like adamantinoma underwent resection of a 10 cm segment of tibia followed by reconstruction with a bone allograft. At five years' follow-up he remains pain-free, has full function of the leg and shows no recurrence.3,5

Outlook

What is the outlook along the OFD spectrum?

Classic OFD
Excellent
Minimal recurrence after skeletal maturity
OFD-like adamantinoma — local control
80–90%
Recurrence in 10–15% after wide excision
Classic adamantinoma — 5-yr survival
>95%
Local recurrence 15–30%; metastases 10–15%

Outcomes are strongly driven by where the lesion sits on the spectrum. Classic OFD has an excellent prognosis; OFD-like and classic adamantinoma need lifelong follow-up with periodic imaging to catch late recurrences early.1,5,6

Decision Guide

Which approach is best for me?

Observation if…
  • • Biopsy confirms classic OFD
  • • The lesion is asymptomatic and stable
  • • There is no significant tibial bowing or fracture risk
Wide excision if…
  • • Biopsy shows OFD-like adamantinoma
  • • The lesion is enlarging or painful
  • • Imaging shows cortical breach or soft-tissue extension
En bloc resection if…
  • • Biopsy confirms classic adamantinoma
  • • Reconstruction with endoprosthesis, allograft or vascularised fibula is feasible
  • • Amputation reserved for tumours that cannot be safely reconstructed
Follow-up

Long-term monitoring plan

Classic OFD
  • • Clinical review and X-ray every 6–12 months until skeletal maturity
  • • Watch for new pain, enlargement or cortical breach
  • • Extended surveillance if biopsy features are borderline

1,4

OFD-like & classic adamantinoma
  • • First 2 years: every 3–4 months
  • • Years 3–5: every 6 months
  • • Beyond 5 years: annually, for life
  • • Extended surveillance is essential — recurrence can appear years later

1,5,6

Next Steps

Next Steps — Talk to a Specialist

Book an AppointmentContact the clinic
Sources

References

  1. 1Van Rijn RR et al. — Adamantinoma: an updated review of the imaging, pathology and management. NCBI PMC, 2021.
  2. 2Zhang Z et al. — Epidemiological study of adamantinoma from the SEER database. NCBI PMC, 2020.
  3. 3Kinnunen AR et al. — Custom total tibia endoprosthesis reconstruction after resection of tibial tumours. NCBI PMC, 2018.
  4. 4OrthoInfo (AAOS) — Osteofibrous Dysplasia and Adamantinoma: patient information article.
  5. 5IJORO — Long-term outcome of tibial adamantinoma treated with wide excision and reconstruction, 2025.
  6. 6Journal of Orthopaedic Case Reports (JOCR) — Persistent Challenges: A Recurrent Adamantinoma Case Report, 2024.
Medical Disclaimer

Important Notice: This information is provided for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. The content on this page should not be used to diagnose or treat any health condition.

Always seek the advice of a qualified orthopaedic oncologist or healthcare provider with any questions about osteofibrous dysplasia, adamantinoma or any other medical condition.

Treatment decisions are individualised and depend on where the lesion sits on the OFD-adamantinoma spectrum, the child's age and skeletal maturity, symptoms and imaging findings. Only a qualified specialist can determine the most appropriate treatment approach for your situation.

Lifelong follow-up is essential for OFD-like and classic adamantinoma because of the potential for late recurrence and progression along the spectrum.

In case of emergency — severe pain, suspected fracture, or rapid change in a known lesion — seek immediate medical attention or contact your local emergency services.

The Orthoncology Clinic is committed to providing current, evidence-based information while emphasising the importance of professional medical consultation for all health-related decisions.