Osteoid Osteoma
• Benign osseous lesion, usually
occurring in the femur and tibia
• Peripheral area of sclerosis with
lucent central zone (vascular
nidus)
• Patients (age range 7-25) usually
describe pain, worse at night,
relieved by aspirin
• Plain film radiographs may
demonstrate a focal area of
sclerosis, but this is not uniform,
and findings may be confused
with other diagnoses such as
stress fracture
• If the osteoid osteoma is
intraarticular, a reactive effusion
is usually incited
Slide 1 of 3
Frontal view of the hip demonstrating an area of focal cortical
thickening medially in the subtrochanteric region of the proximal
femur (arrow)
Osteoid osteoma
• Magnetic resonance (MR) imaging is useful in defining the extent of
edema and sclerosis as well as identifying the central nidus
Coronal fast spin echo proton density image centered
over the hip demonstrating cortical thickening and
sclerosis (arrow)
Axial fast inversion recovery image demonstrating
reactive intraosseous high signal edema as well as
the central nidus (arrow)
Slide 2 of 3
Osteoid osteoma
• Computed tomography (CT) can identify the central nidus and also be
used to guided for percutaneous treatment (CT-guided radiofrequency
ablation)
Sagittal reformatted image demonstrating
cortical thickening of the anterior margin
of the proximal femur, as well as the lucent nidus (arrow)
Axial image demonstrating the radiolucent nidus (arrow)
and surrounding sclerosis of this osteoid osteoma of the
subtrochanteric region of the proximal femur
Slide 3 of 3