Type:
Educational Exhibit
Keywords:
Bones, Extremities, Musculoskeletal bone, CT, MR, Conventional radiography, Diagnostic procedure, Education and training
Authors:
F. Barbiera1, E. Murmura1, B. Murmura2, M. Accardi1, A. Botta1, A. Aiello1, T. smeraldi2, L. La Grutta2, R. Lagalla2; 1Sciacca/IT, 2Palermo/IT
DOI:
10.1594/ecr2018/C-2922
Background
Osteoid osteoma is a small spherical tumor with a diameter of 2 cm or less,
composed of a central zone named nidus which is an atypical bone completely enclosed within a well-vascularized stroma (1).
The peripheral sclerotic reaction zone is composed of osteoblasts,
osteoclasts and dilated capillaries surrounding the nidus.
Peripheral nerve fibers are abundant in and around an osteoid osteoma.
Pain is typically at night and it is promptly relieved by the administration of salicylates.
Tumors are classified as cortical,
medullary or subperiosteal on the basis of radiographic findings.
Cortical osteoid osteoma is the classic type of the disease consisting of a small central nidus,
usually radiolucent,
associated with perifocal dense bone.
The medullary type involves the neck of the femur,
vertebra and small bones.
This type is unable to cause peripheral reactive bone formation and consequentially the detection of the nidus may be difficult.
The subperiosteal type most frequently occurs in the intra-articular portion of the bones and may be difficult to detect.
Typical radiographic findings of osteoid osteoma include an intracortical nidus,
which may display a variable amount of mineralization,
accompanied by cortical thickening and reactive sclerosis in a long bone shaft (2).