Osteoid osteoma: the difficult diagnosis

The diagnosis of osteoid osteoma can be difficult. We present eight children where the diagnosis of osteoid osteoma was difficult, due to a clinical history suggesting an alternative diagnosis, misleading radiological findings, or where the osteoid osteoma was in an unusual site. In some cases, diagnosis was only reached after biopsy, despite radiological investigation and radioisotope studies. The diagnosis should be considered in a child with bony pain or bony swelling, especially where the history is a chronic one. We present a radiological algorithm for the investigation of patients suspected of having an osteoid osteoma.     

Osteoid osteoma

Osteoid osteoma is a benign skeletal neoplasm composed of osteoid and woven bone that rarely exceeds 1.5 cm in greatest dimension. The lesion is most commonly located in the cortex of long bones where it is associated with dense, fusiform, reactive sclerosis. Less often, it may be cancellous, where reactive osteosclerosis is usually less intense and may be distant from the lesion. Cancellous lesions are frequently intraarticular (most often in the hip) and may be associated with synovitis and joint effusion. Rarely, osteoid osteomas occur in a subperiosteal location. Patients are usually young, and there is a strong male predominance. Pain is the most common symptom. Radiographs of patients with cortical osteoid osteoma are often diagnostic. Intraarticular lesions, however, may be subtle, and scintigraphy may be required to locate the lesion for subsequent computed tomography (CT). CT is useful to identify and precisely locate the lesion and to provide guidance for percutaneous localization or treatment.     

Osteoid osteoma: CT-guided percutaneous treatment

Seven patients with presumed osteoid osteoma were treated with percutaneous destruction or drill resection with computed tomographic (CT) guidance. The diagnosis of osteoid osteoma was made on the basis of findings in the clinical history and results at plain radiography, bone scintigraphy, and CT. In four patients, histologic confirmation was obtained. Hospital stay lasted from 1 to 3 days. After 11-38 months of follow-up examinations, all patients were asymptomatic. The authors report this simple procedure as an alternative to the more traditional open surgery technique.     

Osteoid osteoma: MR imaging revisited

To assess and compare with computed tomography (CT) the performance of magnetic resonance (MR) imaging in the detection of osteoid osteoma, and determine the features of this lesion on MR imaging. The prospective MR imaging and CT diagnosis of osteoid osteoma was determined from original radiology reports. MR images were assessed retrospectively with regard to the location and signal intensity of the nidus and surrounding bone marrow and soft tissue edema. These findings were correlated with the age of the patient, duration of symptoms, and drug therapy. Ten patients with histologically proven osteoid osteoma who underwent MR imaging were reviewed. All 10 lesions were correctly diagnosed at the time of MR imaging. None of the lesions was intracortical. Nine lesions were intra-articular. Two out of five patients with extracortical lesions had false negative CT preceding the MR study. Signal intensity of the nidus, marrow, and soft tissue edema on MR imaging were variable. Perinidal edema was most pronounced in younger patients and had no apparent relation to drug therapy. MR imaging reliably demonstrates the nidus of an osteoid osteoma, which has a variable appearance related to its position relative to the cortex of the bone. A predominance of cancellous osteoid osteomas are encountered in patients referred for MR imaging. Marrow edema in the vicinity of the lesion improves the conspicuity of the nidus. CT may fail to diagnose osteoid osteoma when the nidus is in a cancellous location, due to the lack of perinidal density alteration.     

Osteoid osteoma in the differential diagnosis of persistent joint pain

We report 20 cases (13 male and 7 female), mean age 21 years) of juxta-articular osteoid osteoma. The distribution of affected joints was as follows: hip joint (7 cases), knee joint (2 cases), ankle joint (2 cases); iliosacral joint (2 cases), lumbar spine (2 cases), carpus (2 cases), shoulder (1 case), second metacarpal (MCP; 1 case) and first metatarsal (MTP; 1 case). The duration between the onset of symptoms and diagnosis varied from 8 months to approximately 4 years. In juxta-articular osteoid osteoma, the clinical picture and the radiographic findings are often atypical, and this may lead to misdiagnosis and delayed definitive treatment. In young patients with persistent undiagnosed pain, the possibility of an osteoid osteoma should be considered. When the clinical picture is suggestive but radiological findings are negative, we must proceed to further investigation with bone scintigraphy and computed tomography. These examinations should be repeated 1 year after the onset of symptoms because initially negative findings may become positive at a later date. When the diagnosis of an osteoid osteoma is confirmed, surgical excision leads to complete relief of the symptoms.     

Osteoid osteoma: excision with scintimetric guidance

The definite diagnosis of osteoid osteoma relies on the demonstration of the nidus, best shown by CT, which also provides precise preoperative localization of the nidus. While bone-block excision to remove the nidus is feasible in the long bones, there may be unacceptable sequelae in the vertebral column and small bones of the hands. By precisely localizing the nidus, radionuclide scintimetry permits excellent therapeutic results, with minimal morbidity.     

Osteoid osteoma: radiologic and pathologic correlation

Sixty-seven cases of osteoid osteoma were studied at the Hospital for Joint Diseases between 1980 and 1989. The lesions were categorized according to location: medullary, cortical, or subperiosteal and were further grouped as intracapsular and extracapsular. The histologic features of trabecular thickness, reactive bone formation, proportion of fibrovascular stroma, and ratio of osteoid and mineralized matrix were examined. The radiographic features were compared. The literature is reviewed. We include our experience with tetracycline labelling.     

Osteoid osteoma: clinical results with thermocoagulation

PURPOSE: To determine the clinical results in an unselected group of consecutive patients with osteoid osteoma treated with thermocoagulation. MATERIALS AND METHODS: In 97 consecutive patients with clinical and/or radiologic evidence of osteoid osteoma at any location, the clinical symptoms were assessed before and after thermocoagulation with computed tomographic guidance. A good response was defined as disappearance of symptoms that were manifested at presentation and attributed to osteoid osteoma. Clinical assessment was performed prior to discharge; within 2 weeks after the procedure; and at 3, 6, 12, and 24 months follow-up. After 24 months, a postal questionnaire was used for assessment. RESULTS: The mean clinical follow-up after the only or the last thermocoagulation session was 41 months (range, 5-81 months). Response was good after one session of thermocoagulation in 74 (76%) of 97 patients, and the 95% CI was 68% to 85%. Patients with persistent symptoms did well after repeated thermocoagulation (good response in 10 of 12 patients), but results of repeated thermocoagulation were poor in patients with recurrent symptoms (good response in five of 10). The overall success rate after one or two thermocoagulation procedures combined was 92% (89 of 97 patients), and the 95% CI was 86% to 97%. Complications were observed in two patients. CONCLUSION: Percutaneous thermocoagulation is a safe and effective method for treatment of osteoid osteoma at any location. Repeated thermocoagulation is successful in patients with persistent symptoms.     

Osteoid osteoma in the mandible

A case of osteoid osteoma (OO) in the mandible of 26-year-old female is presented. Her main complaint was intermittent pain during a 3 year period. The panoramic radiograph of the mandible showed diffuse sclerosis including an ill-defined circular radiopacity in the molar region. Computed tomography (CT) revealed an osseous lesion of 10 mm diameter that was located in the cortical bone of the mandible. Bone scintigraphy showed a localized region of high uptake of 99mTc HMDP. The lesion was diagnosed as an OO by histopathological examination of the surgical specimen and CT findings. Since radiological appearance has very significant meaning in the differentiation of an OO from other bone forming tumors, CT is the method of choice when the main symptom is pain and the conventional radiography was not informative.     

Osteoid osteoma of the elbow

Six cases of osteoid osteoma of the elbow were reviewed to determine the spectrum of clinical, pathologic and radiologic findings. Since osteoid osteoma of the elbow may masquerade as a nonspecific synovitis, the diagnosis is challenging and frequently delayed. The histology is, however, indistinguishable from that of osteoid osteoma occurring in typical locations. The radiologic features of osteoid osteoma of the elbow include the following triad: (a) osteosclerosis, usually a dominant feature at initial imaging and typically enveloping the nidus; (b) joint effusion; and (c) periosteal reaction that can involve both the bone in which the osteoid osteoma arises and adjacent bones. Awareness of these features will facilitate correct diagnosis, thereby facilitating timely and appropriate treatment.The opinions and assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army, the Department of Defense or the Uniformed Services University of the Health Sciences     

Osteoid osteoma of the spine

High resolution CT has become crucial to the definite diagnosis, accurate localisation and extension of benign spinal tumors. An osteoid osteoma mostly suspected by X-ray or scintigraphy, located in the axial skeleton--mainly of spongious content and with a complex anatomical structure--will be definitely more distinctly visualized on CT. Post-operative evaluation also requires CT.     

Osteoid osteoma of the cervical spine

Summary The authors studied the usefulness of MR imaging in the diagnosis of an osteoid osteoma occuring within the C4 left uncinate process. It was detected by scintigraphy and diagnosed by CT. On T2-weighted MR images the nidus showed a very low signal intensity with an increased signal within the adjacent end-plates. This pattern was misleading and more suggestive of degenerative disk disease.