Histological evaluation of drill fragments obtained during osteoid osteoma radiofrequency ablation.

OBJECTIVE: Osteoid osteoma (OO) is a benign bone tumor diagnosed mainly on the basis of the patient's history and radiological data. Histological evaluation may not be available before treatment. The aim of this study was to assess the diagnostic value of a histological evaluation of the bone fragments obtained during radiofrequency ablation (RFA).

MATERIALS AND METHODS: During a 2-year period, 39 patients diagnosed clinically with OO were entered into this study. The procedure was performed under computed tomography (CT) guidance. An 11-gauge needle was initially placed as a coaxial guide. After drill removal, RFA was performed. Bone fragments collected from the drill were examined by two experienced pathologists, independently.

RESULTS: There was strong association between pathologists' reports (P <0.001). In 27 cases (69.2%) this diagnosis was confirmed pathologically. No significant relationship was found between nidus diameter and positive histological findings (P = 0.35).

CONCLUSION: Histological confirmation of OO based on drill fragments is similarly frequent as previously reported for standard bone biopsy.