Osteoid Osteoma – Synopsis of clinical, radiological, and therapeutical relevance of this rare entity

Abstract

Characteristic of the osteoid osteoma is the so-called nidus enclosed in the tumor and produces a typical picture on X-ray. Since most physicians have little experience with the clinical picture of osteoid osteoma, this is an important reason for the often-long anamnesis time for osteoid osteoma (OO). The period of formation of OO includes the phase of strongest bone growth in childhood and adolescence. The most characteristic clinical symptom is nocturnal attacks of pain around the tumor, which occur independently of preceding physical activity and respond strikingly well to non-steroidal anti-inflammatory drugs (aspirin test). OO most frequently affects the long tubular bones of the lower extremities. Fifty percent of OO are found in the femur and tibia preferentially occurring in the corticalis of metaphysis and diaphysis. This is followed by the long tubular bones of the upper extremity and the short tubular bones. However, any other bone can also be affected. Differentially, osteoblastoma or osteosarcoma must be considered first and foremost. Most widely accepted therapy options are open surgery with en-bloc resection of the tumor, excochleation,minimally invasive percutaneous CT-guided radio or laser ablation. A conservative management by pharmaceutical pain therapy should be reserved for cases in which surgery must be refused either because of the precarious position of the nidus or because the patient's general condition does not permit it, or the patient does not consent to surgical interventions.