Osteoid osteoma of the femur
Updates to Case Attributes
Osteoid Osteomaosteoma is a benign osteoblastic tumor that is usually less than 2 cm in size. It consists of a central vascularized nidus that represents the neoplastic tissue. The nidus is surrounded by normal reactive bone. It is most frequently found in long bones, such as the femur and tibia, but can occur at any site. Cortical thickening surrounding a small central core of lower density, the nidus, are the classical radiological finding.
X-rays may be normal; however, the cortical thickening is generally well visualised with this imaging modality. The central “nidus” is sometimes visible on x-rays as a well-circumscribed lucent region, occasionally with a central sclerotic dot. CT imaging considered to be the imaging modality of choice. On this imaging modality appearing as a focally lucent area within surrounding sclerotic reactive bone. In juxta-articular localisation, the reactive sclerosis may be absent.
Kayser et al. have classified osteoid osteoma into four categories according to the relation of the lesion with the bone cortex: subperiosteal (located on the external aspect of the cortex, surrounded by periosteal reaction), intracortical (located within the cortex), endosteal (on the internal of the cortex) and medullary (located within the medullary bone).
-<p>Osteoid Osteoma is a benign osteoblastic tumor that is usually less than 2 cm in size. It consists of a central vascularized nidus that represents the neoplastic tissue. The nidus is surrounded by normal reactive bone. It is most frequently found in long bones, such as the femur and tibia, but can occur at any site. Cortical thickening surrounding a small central core of lower density, the nidus, are the classical radiological finding. X-rays may be normal; however, the cortical thickening is generally well visualised with this imaging modality. The central “nidus” is sometimes visible on x-rays as a well-circumscribed lucent region, occasionally with a central sclerotic dot. CT imaging considered to be the imaging modality of choice. On this imaging modality appearing as a focally lucent area within surrounding sclerotic reactive bone. In juxta-articular localisation, the reactive sclerosis may be absent. Kayser et al. have classified osteoid osteoma into four categories according to the relation of the lesion with the bone cortex: subperiosteal (located on the external aspect of the cortex, surrounded by periosteal reaction), intracortical (located within the cortex), endosteal (on the internal of the cortex) and medullary (located within the medullary bone).</p>- +<p><a title="Osteoid osteoma" href="/articles/osteoid-osteoma">Osteoid osteoma</a> is a benign osteoblastic tumor that is usually less than 2 cm in size. It consists of a central vascularized nidus that represents the neoplastic tissue. The nidus is surrounded by normal reactive bone. It is most frequently found in long bones, such as the femur and tibia, but can occur at any site. Cortical thickening surrounding a small central core of lower density, the nidus, are the classical radiological finding.</p><p>X-rays may be normal; however, the cortical thickening is generally well visualised with this imaging modality. The central “nidus” is sometimes visible on x-rays as a well-circumscribed lucent region, occasionally with a central sclerotic dot. CT imaging considered to be the imaging modality of choice. On this imaging modality appearing as a focally lucent area within surrounding sclerotic reactive bone. In juxta-articular localisation, the reactive sclerosis may be absent.</p><p>Kayser et al. have classified osteoid osteoma into four categories according to the relation of the lesion with the bone cortex: subperiosteal (located on the external aspect of the cortex, surrounded by periosteal reaction), intracortical (located within the cortex), endosteal (on the internal of the cortex) and medullary (located within the medullary bone).</p>
Updates to Study Attributes
Rx right femur
Radiograph shows fusiform cortical thickening of the anterolateral cortex of the proximal femur.
Updates to Study Attributes
CT right femur without contrast
Ther’sThere is a small intracortical osteolytic lesion without central calcification, surrounded by a prominent zone of reactive sclerosis due to a periosteal and endosteal reaction.
Updates to Study Attributes
MRI right femur with contrast
MR T1 coronal image demonstrates the wide cortical thickening. T1-weighted images show the low-signal-intensity nidus, which has strong enhancement. STIR images shows a intracortical osteoid osteoma of the right proximal femur, with inflammatory reaction in the adjacent cancellous bone and in the soft tissues.