A 21-year- old female patient presented to the orthopaedic outpatient department with complaints of non-traumatic neck pain relieved by analgesics. The local and neurological examination was normal. Laboratory investigations were within normal limits. The patient was referred for radiograph of the cervical spine and later MRI was done.
Plain radiograph of cervical spine lateral view showed straightening of cervical spine [Fig. 1]. MRI of cervical spine revealed altered signal intensity of C5 vertebral body in the form of T2/STIR hyperintensity and T1 hypointensity suggestive of marrow oedema [Fig. 2]. No evidence of abnormal post contrast enhancement noted in the lesion. Rest of the vertebrae, intervertebral discs and cervical cord were normal. Correlative CT study showed a well-defined hypodense lesion (7mm) with central sclerotic nidus and perilesional sclerosis in right postero-lateral aspect of C5 vertebral body [Fig. 3].
Osteoid osteoma is a benign osteoblastic lesion containing a small nidus of highly vascular connective tissue with varying amounts of osteoblastic elements and surrounding sclerotic bone [1, 2].
Clinically patients present with localised pain over months which aggravates with movement and promptly relieves by analgesics [1, 3, 4]. The response to salicylates has recently been found to be equivocal (between 30%- 75%)[5]. Majority of the cases occur during 5-25 years of age, with a male to female ratio of 2-3:1 [1, 2, 3].
There are two types of osteoid osteoma– cortical (common) and cancellous/medullary variety [5, 6].
Commonest sites of occurrence are the long bones [1, 2]. Involvement of vertebra is uncommon (in 10% of cases). If involved, however, posterior elements are the common sites [2] with only around 7% involving the vertebral body [1, 4].
Conventional radiography is helpful in visualising the radiolucent/sclerotic nidus of the lesion but most of the times it fails to show the same in a spinal lesion due to the complex spinal anatomy [1, 6, 7].
Radionuclide scan (Tc 99 MDP) is a more sensitive and reliable modality than radiography as it is invariably positive and shows the characteristic “double density” sign [1, 5, 8].
CT helps in localising the nidus of the lesion with consistency, making it an accurate and reliable investigation (gold standard) particularly in lesions located in the spine [1, 8, 9]. The nidus is seen as a well-defined, smooth-marginated, hypodense region with surrounding sclerosis.
MRI shows a variable appearance depending upon the extent of calcification of nidus, presence of reactive sclerosis and size of the fibrovascular zone [1]. Predominantly the lesion is of low to intermediate signal intensity on T1 and low to high signal intensity on T2 weighted images [7, 8, 10]. Osteiod osteoma’s variable appearance on MRI has led to various misdiagnoses such as malignant tumour, osteomyelitis and stress fracture [9].
In majority of cases the actual nidus is not defined on MRI, but it is sensitive in detecting reactive marrow oedema [1, 2, 9] and effects on the spinal cord [7].
CT with or without radionuclide scintigraphy is the best modality and MRI is never interpreted without a radiograph/CT evaluation [9].
Surgical excision of the nidus is the definitive therapy especially in case of children and adolescents in order to prevent structural deformity [5]. Other options include medical management - NSAIDs with observation, CT guided percutaneous ablation techniques [5].
Osteoid osteoma of the cervical vertebral body.
Based on the provided X-ray, CT, and MRI results, the main radiographic findings are as follows:
▪ On the lateral cervical spine X-ray, mild bony abnormalities can be observed at the local vertebral body or lamina (or pedicle). These appear as slight sclerosis or localized lucent areas with relatively blurred margins, making it difficult to clearly delineate the exact shape of the lesion.
▪ On MRI, the lesion may show heterogeneous signal changes: on T1-weighted images, it often appears as low to moderate signal; on T2-weighted images, there may be areas of high signal. Local soft tissue or vertebral body may show varying degrees of edema or inflammatory response.
▪ CT scans can more clearly display the “nidus” of the lesion: the nidus typically has a relatively smooth margin with varying degrees of surrounding sclerosis (osteoblastic change and sclerotic rim). CT can precisely locate the lesion within the vertebral body or posterior part of the pedicle, showing the typical small lucent focus encircled by dense sclerotic bone.
Taking into account the patient’s age, symptoms (pain worsening at night or during rest, relieved by analgesics), and typical imaging features, the following diagnoses are considered:
1) Osteoid Osteoma:
• Primarily occurs in young individuals, often presenting with progressively worsening local pain, especially prominent at night;
• Radiographically shows a “nidus,” accompanied by significant surrounding osteosclerosis;
• Pain is notably relieved by NSAIDs (such as aspirin), which is characteristic.
2) Osteoblastoma:
• Similar in nature to osteoid osteoma, can present with bony proliferation and a small focus, but typically larger in size and may cause more severe pain;
• Imaging may show a larger lytic lesion with a distinct sclerotic margin.
3) Infectious lesions (e.g., vertebral osteomyelitis) or other benign tumors:
• Infection should be considered when there is local edema or abnormal MRI signals; however, clinically, infection usually presents with fever or elevated inflammatory markers. At this time, the patient’s laboratory results are essentially normal, making infection less likely.
• Other benign tumors, such as enchondroma or hemangioma, might also present with certain characteristic features in the bone, but they usually do not match the classic “nidus” and surrounding sclerosis seen with osteoid osteoma.
Considering the patient is a young female, with characteristic symptoms (non-traumatic neck pain relieved by analgesics), imaging findings of a nidus and surrounding sclerosis, and no significant abnormalities in laboratory tests, the most likely diagnosis is:
Osteoid Osteoma.
If further confirmation is needed, a CT-guided biopsy or additional investigations may be conducted based on clinical requirements. However, based on the current evidence, osteoid osteoma is highly suspected.
This report provides a reference analysis based on current imaging and clinical information and does not substitute an in-person consultation or a professional medical opinion. For any questions or changes in condition, please seek timely medical attention for further diagnosis and treatment.
Osteoid osteoma of the cervical vertebral body.
