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Curriculum · Musculoskeletal / Orthopedic / Rheumatology

Osteoid osteoma

What it is

Osteoid osteoma is one of the bone tumours that come from osteoblast. The benign ones of that group are osteoma, osteoid osteoma, and osteoblastoma, and the malignant one is osteosarcoma. Its location is the diaphysis, the age given for it is less than 25 years, and the feature that marks it is a nidus that secretes prostaglandin.

How it presents

The pain is constant and progressive over the diaphysis of a long bone, the tibia being the site described, and it is worse at night. It is relieved by NSAIDs, or by anti-inflammatory medication, but it is not relieved by rest. In the list of tumour clues, bone pain relieved by aspirin points to osteoid osteoma.