Osteoblastoma
 

Osteogenic benign tumor whose histological appearance is very similar to that of osteoid osteoma. The osteoid is arranged less regularly.

In borderline cases it is considered that this is a Osteoblastoma if the tumor is> 15mm

Rarer than osteoid osteoma (3.5% of benign primary tumors).

 

Men> Women (2/1)

Age: 5-25 years (85% of cases).

 
Location:

 - Spine (60%), especially on the rear> femur (10%)> Tibia (8%)> Sacrum bow mandibles

 
 Clinic:

 - Very close to that of osteoid osteoma.

- Toxic form (rare): fever, poor general condition, biological inflammation

- Form locally aggressive (rare, especially sacrum).

- Spine: Painful scoliosis can

 
Biology

 - Osteomalacia / rickets oncogenic: the tumor can secrete a hormone

- Phosphaturiante (phosphatonin or FGF 23).

 
Radiology / Scanner:

        - Variable size and highly polymorphic radiological appearance

       - Four main kinds radiological

  1 Big osteoid osteoma (> 15mm)

        Reaction Osteosclerosis less frequent than in osteoid osteoma
        multifocal mineralized matrix and noncentral

  2 Injury blower near the cyst aneurysmal

The presence of intratumoral ossification (very inconsistent) may help differentiate osteoblastoma aneurysmal bone cyst. There are forms with aneurysmal bone cyst (secondary) associated with osteoblastoma.

  3 osteolytic lesion pseudométastatique

  4 Injury osteogenic osteosarcoma recalling with a less aggressive appearance.

    - Spine: may affect two adjacent vertebrae (joint).

 
MRI:

 - Central lesion intermediate signal in T1 and T2, taking intense contrast in the arterial phase (such as osteoid osteoma).

       - Bone edema and / or adjacent soft tissues as in osteoid osteoma

       - Levels sero-hematic possible especially in forms or blowers associated with aneurysmal cyst

 
Bone scintigraphy

        - Intense uptake at the early time

 
Treatment:

      - Careful surgical excision Reduced to curettage for sensitive locations

 

      - Treatment by percutaneous radiofrequency or cryotherapy can be tried in the forms not too large

Frequent recurrence (30-50%)

 

 
Remember:

 

Highly polymorphic Image

A mention to a very limited fan lytic lesion of the posterior arch

Search for a calcified matrix for differentiating an aneurysmal cyst

Form with oncogenic osteomalacia

 
  
 

 

04 osteoblastoma peudométastatique blade C5. Rate aspect blowing pseudotumoral and low peripheral osteosclerosis

 

 



05 osteoblastoma mimicking a large cervical osteoid osteoma. Note the multifocal mineralized matrix and not of central Osteoblastoma

 

 

Tibial osteoblastoma with oncogenic hypophosphatemic rickets. Note the expansion of the growth plate associated with rickets.