Osteoid Osteoma - Diagnostic and Therapeutic Difficulties. A. Single-centre Experience.

BACKGROUND Osteoid osteoma is a primary, benign bone tumour. The characteristic clinical symptom is nocturnal pain at the tumour site that decreases or resolves completely with salicylates and non-steroidal antiinflammatory drugs (NSAIDs). The typical radiological features include a radiolucent area with an osteosclerotic rim. An unusual location or absence of visible abnormalities on conventional radiographs may pose a diagnostic challenge. MATERIAL AND METHODS We report our clinical experience with osteoid osteoma in 15 patients, with special regard to diagnostic and therapeutic difficulties in two cases. RESULTS All patients reported the characteristic pattern of nocturnal pain that was reduced or resolved after administration of aspirin or NSAIDs. A typical radiological appearance of osteoid osteoma was observed in 13 patients, with radiological studies showing no changes in two patients, who required extended imaging workup to establish the diagnosis. CONCLUSIONS 1. Osteoid osteoma may be a diagnostic and therapeutic problem. 2. Lack of visible abnormalities on conventional radiographs in the presence of typical clinical symptoms does not rule out osteoid osteoma. 3. Bone scintigraphy and magnetic resonance imaging are helpful methods in the imaging of radiologically silent pathological lesions.