Radiological Features of Osteoid Osteoma: Pictorial Review

Abstract

: Osteoid osteoma is a benign bone tumor of undetermined etiology, composed of a central zone named nidus which is an atypical bone completely enclosed within a wellvascularized stroma and a peripheral sclerotic reaction zone. There are three types of radiographic features: cortical, medullary and subperiosteal. Forty-four patients with osteoid osteoma were studied retrospectively. In plain films, 35 patients presented as the cortical type, six cases were located in the medullary zone and three had subperiosteal osteoid osteoma. In all the cases, the nidus was visualized on computed tomography (CT) scan. The nidus was visible in four out of five patients who had also undergone magnetic resonance imaging (MRI). Double-density sign, seen on radionuclide bone scanswas positive in all patients. MRI is more sensitive in the diagnosis of bone marrow and soft tissue abnormalities adjacent to the lesion, and in the nidus that is located closer to the medullary zone. On the other hand, CT is more specific when it comes to detecting the lesion’s nidus. Implication for health policy/practice/research/medical education:This pictorial essay provides medical imaging information about osteoid osteoma for educational objectives. Please cite this paper as:Hashemi J, Gharahdaghi M, Ansaripour E, Jedi F, Hashemi S. Radiological Features of Osteoid Osteoma: Pictorial Review. Iran J Radiol.2011; 8(3):182-9. DOI: 10.5812/kmp.iranjradiol.17351065.3392 Copyright © 2011, Tehran University of Medical Sciences and Iranian Society of Radiology. Published by Kowsar M.P.Co. All rights reserved.