Osteoid osteoma (OO) (synonyms: osteoblastic tumor; ICD-10-GM D16.9: Benign neoplasm of bone and articular cartilage, unspecified) is a benign (benign) neoplasm (neoplasm) of bone arising from osteoblasts (bone-forming cells). The tumor is located centrally or eccentrically in the bone and is very small (pinhead to cherry pit sized) tumor.
Osteoid osteoma is one of the primary bone tumors. Typical for primary tumors is their respective course and that they can be assigned to a certain age range (see “Frequency peak”) as well as a characteristic localization (see under “Symptoms – complaints”). They occur more frequently at the sites of most intensive longitudinal growth (metaepiphyseal/articular region). This explains why bone tumors occur more frequently during puberty. They grow infiltratively (invading/displacing), crossing anatomical boundary layers. Secondary bone tumors also grow infiltratively, but usually do not cross boundaries.
Sex ratio: boys/men are more commonly affected than girls/women.
Peak incidence: osteoid osteoma occurs predominantly between the ages of 10 and 20, rarely after the age of 30.
Osteoid osteoma accounts for 4% of all bone tumors, making it relatively common (third most common benign bone tumor, after osteochondroma (12%) and enchondroma (10%)).
The course and prognosis depend on the location and extent of the bone tumor. In benign (benign) tumors, it is initially possible to wait and observe (“watch and wait” strategy). Thus, an osteoid osteoma disappears spontaneously in 30% of cases, even without treatment. If the pain, which occurs mainly at night, is very severe, or the osteoid osteoma causes further discomfort, it is surgically removed.
In general, the prognosis for patients with osteoid osteoma is very good. Malignant (malignant) degeneration has not been reported.
