Osteoid osteoma simulating osteomyelitis: Differentiation with Tc-99m HIG scintigraphy

We present a case of osteoid osteoma with a history of mild pain, local swelling and point tenderness on the right lower leg. The diagnosis of osteoid osteoma was difficult due to the atypical clinical history and misleading radiological and bone scan findings. When it is difficult to differentiate an osteoid osteoma from osteomyelitis using CT, MRI or bone scan; HIG scintigraphy can be used to exclude an infection.     

Bone scintigraphy as a guide to the diagnosis of osteoid osteoma.

This report describes one case in which bone scintigraphy was helpful in establishing the diagnosis of osteoid osteoma and presents three other cases in which increased accumulation of 99mmTc-EHDP was found at the side of the osteoid osteoma. The study contributes to the observation by others that the osteoid osteoma occurs as a scintigraphic 'hotspot'. It is concluded that the diagnostic delay of the osteoid osteoma can be shortened when bone scintigraphy is performed more often and at an earlier stage in patients with unexplained bone pain or with a clinical history that leads to the suspicion of the presence of an osteoid osteoma.     

Intra-articular hip joint osteoid osteoma: Challenging diagnosis and percutaneous radiofrequency ablation treatment

Atypical intra-articular osteoid osteoma can be difficult to diagnose and challenging to treat. We report a case of a right acetabular subchondral intra-articular osteoid osteoma in a young male patient which was initially diagnosed as femoroacetabular impingement due to its atypical clinical and radiological presentations. After fully working up the patient the lesion was successfully treated with percutaneous CT-guided low-power bipolar radiofrequency ablation using several per procedural articular cartilage thermal protective measures including intra-articular thermocouple, and continuous per procedural joint space cooling with Dextrose 5% solution. A precise RFA electrode placement, using the No-touch technique, and applying different passive and active thermal protective measures were helpful in avoiding collateral damage of the hip joint articular cartilages. atypical intra-articular osteoid osteomas necessitate pertinent correlation between the clinical and radiological presentations. As far as intra-articular or subchondral nidus ablation is concerned, thermal protective measures should be considered.     

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.     

Symptomatic resolution of spinal osteoid osteoma with conservative management: imaging correlation

A 10-year-old girl presented with a history of painful scoliosis. Imaging performed, including computed tomography (CT) and magnetic resonance imaging (MRI), demonstrated a lesion with radiological features consistent with an osteoid osteoma (OO) of the 6th thoracic vertebra. The patient was treated conservatively with non-steroidal anti-inflammatory drugs (NSAIDs). Over eight months of clinical and radiological surveillance, she became entirely asymptomatic and demonstrated complete resolution of the scoliotic curve. The CT and MRI features of the osteoid osteoma during the period of surveillance are presented and are correlated with the corresponding clinical features.     

Computed tomography and plain film appearance of a bony sequestration: significance and differential diagnosis

Bony sequestration has been reported in osteomyelitis, eosinophilic granuloma, and fibrosarcoma. Thirty-eight examples of radiographically apparent bony sequestra were collected to examine the validity of this differential diagnosis. Apparent sequestra were found in osteomyelitis (59%), fibrosarcoma or fibrosarcoma-like entities (13%), eosinophilic granuloma (8%), and osteoid osteoma (21%). Although osteoid osteoma does not contain a true bony sequestrum, the partially calcified nidus was radiographically mistaken for a sequestrum in eight (21%) of our cases and, therefore, should be considered when an apparent sequestrum is visualized. Computed tomography enhanced visualization of a sequestrum in 19 of 22 cases and is recommended as an adjunct to conventional radiography when the presence of a sequestrum will alter therapy.Presented at the Seventy-First Scientific Assembly and Annual Meeting of the RSNA, Chicago, Illinois, November 1985     

骨样骨瘤的CT表现特点

目的 :分析骨样骨瘤的CT表现特点。方法 :回顾性分析 3 8例经手术病理证实的骨样骨瘤的CT表现特点。结果 :3 8例中股骨 2 1例 ,胫骨 5例 ,肱骨 3例 ,其他部位 9例。 3 8例中 3 7例有瘤巢中心钙化 ,形成“牛眼征” ;瘤巢周围见骨质硬化者 3 3例 ;骨膜反应 13例 ,内骨膜增生 8例 ,外骨膜增生 2例 ,内外骨膜均增生 3例。 9例骨髓腔内出现骨质吸收的改变。结论 :骨样骨瘤的CT表现典型 ,CT是目前诊断骨样骨瘤的常用检查技术。     

Unusual manifestation of vertebral osteoid osteoma: case report

We report the case of a 64 year-old man with a clinical history suggesting a low thoracic-cord involvement, in which an unexpected vertebral osteoid osteoma was discovered. The patient underwent MRI of the thoraco-lumbar spine, which included sagittal and axial T1-weighted images, and sagittal double-echo T2-weighted images. Subsequently, CT scan was carried out with 2-mm-thick axial sections, aimed at T10 vertebra. Magnetic resonance imaging disclosed an extra-axial mass at T10 level. Computed tomography scan suggested an osteoid osteoma of the tenth thoracic vertebra, involving the lamina with marked sclerosis and prevalently endocanalar extension. Histology following surgical resection confirmed the diagnosis. In the reported case CT scan provided the correct pre-operative diagnosis of osteoid osteoma despite its unusual clinical--anamnestic presentation. Magnetic resonance imaging was useful in establishing the relationship of the neoplasm with the spinal cord.     

Collar-type osteophyte of the femur in young adults: is it a harbinger of intra-articular osteoid osteoma?

Variable clinical and radiological findings for intra-articular osteoid osteoma (OO) of the hip joint make its diagnosis difficult. Because radiographs commonly do not identify the nidus, MR imaging becomes the second line of study. However, because the appearance varies, findings on MR images can be confusing. We found “collar type osteophyte” of the femur i.e. an osteophyte rim around the femoral neck, to be a conspicuous finding of intra-articular OO. Here, this feature will be emphasized and intra-articular OOs will be discussed, with a review of the literature.     

Localisation and diagnosis of osteoid osteoma of the carpal area by angiography

Three patients are reported in whom the existence and exact localisation of an osteoid osteoma in the carpal area was established only by angiography. In each case demonstration of the lesion by conventional roentgenograms, including fine-section tomograms, had failed. This failure, together with initially atypical clinical symptoms, significantly delayed diagnosis, to such an extent that one patient was referred for a psychiatric opinion. The first valid diagnostic clue was provided in two cases by bone scanning, but with inadequate detail to show precisely the position of the lesion. This study re-emphasizes the value of angiography when an osteoid osteoma presents no characteristic radiological stigmata.     

Osteoid osteoma of the petrous bone

We present a case of osteoid osteoma of the petrous bone presenting with progressive sensorineural hearing loss. CT showed a dense homogeneous mass at the promontory surrounded by a thin bony border. On MRI this lesion gave intermediate signal intensity on T1- and T2-weighted spin-echo images and enhanced intensely with gadolinium. Surgical removal and pathological study proved the diagnosis. Received: 13 February 1997 Accepted: 21 February 1997     

CT of osteoid osteoma of the femoral neck: the value of oblique reformatting

An osteoid osteoma is a benign bone lesion which may involve the femoral neck. The lesions are distinctively osteoblastic, containing a central fibrovascular and osteoid nidus which often evokes substantial periosteal reaction occasionally making the diagnosis by conventional radiography very difficult. Computed tomographic evaluation of these lesions at other sites has been previously reported. I wish to emphasize the unique value of CT multiplanar reformatting in a patient with an osteoid osteoma of the femoral neck.     

The diagnostic accuracy of MR imaging in osteoid osteoma

OBJECTIVE: To analyse the MR imaging appearances of a large series of osteoid osteomas, to assess the ability of MR imaging to detect the tumour, and to identify potential reasons for misdiagnosis. DESIGN AND PATIENTS: The MR imaging findings of 43 patients with osteoid osteoma were reviewed retrospectively and then compared with other imaging modalities to assess the accuracy of MR localisation and interpretation. RESULTS: The potential for a missed diagnosis was 35% based solely on the MR investigations. This included six tumours which were not seen and nine which were poorly visualised. The major determinants of the diagnostic accuracy of MR imaging were the MR technique, skeletal location, and preliminary radiographic appearances. There was a wide spectrum of MR signal appearances of the lesion. The tumour was identified in 65% of sequences performed in the axial plane. The nidus was present in only one slice of the optimal sequence in 27 patients. Reactive bone changes were present in 33 and soft tissue changes in 37 patients. CONCLUSION: Reliance on MR imaging alone may lead to misdiagnosis. As the osteoid osteoma may be difficult to identify and the MR features easily misinterpreted, optimisation of MR technique is crucial in reducing the risk of missing the diagnosis. Unexplained areas of bone marrow oedema in particular require further imaging (scintigraphy and CT) to exclude an osteoid osteoma.     

Osteoid osteoma of the second metatarsal bone diagnosed on MRI: A case report and literature review

Osteoid osteoma is a relatively common benign bone tumor that is most frequently seen on the appendicular skeleton in adolescents and young adults. Here we present the case of a 14-year-old boy presenting with a 10 month history of pain in his left foot which had been misdiagnosed as stress fracture due to its unusual clinical presentation. Magnetic resonance imaging of the left foot revealed a bone lesion with typical features of the osteoid osteoma on the distal part of the second metatarsal bone. The lesion was surgically removed and the diagnosis of osteoid osteoma was confirmed by post-surgical histopathologic examination of the resected section. The patient reported a substantial relief in his pain 4 weeks following the surgical operation.     

Recurrent osteoid osteoma: a case report with imaging features

We present a case of a 14-year-old boy, who presented with pain in the left thigh region for 1 year. The pain exacerbated at night, waking up the child and was relieved by salicylates. On the basis of clinical history, conventional radiography, computerized tomography and bone scintigraphy, a diagnosis of osteoid osteoma was made. The tumor was completely excised, and there was complete remission of symptoms. Six months following surgery, the pain recurred in the same region. Conventional radiography revealed dense sclerosis at the surgical site. Three-phase skeletal scintigraphy showed a focal area of increased blood pool activity followed by intense focal uptake in delayed images, characteristic of osteoid osteoma. Computerized tomography confirmed the findings of skeletal scintigraphy.     

Osteoid osteoma of the femur in a 7-month-old infant treated with radiofrequency ablation

Osteoid osteoma occurs most commonly in children, adolescents, and young adults between the ages of 5 and 30 years. In the preschool age group, it is quite uncommon, accounting for only 3–8% of all osteoid osteoma cases. We report a case of osteoid osteoma in a 7-month-old infant, who presented with decreased use of the right lower extremity due to pain. Magnetic resonance imaging (MRI) showed an atypical appearance. A biopsy of the lesion, with histopathological examination, confirmed the diagnosis of osteoid osteoma. Radiofrequency ablation (RFA) of the nidus under computed tomography (CT) guidance was performed. The patient developed a recurrence after 3 months, which was treated with a second RFA. On subsequent follow-up, the infant did not show signs of pain after 1 month. In summary, this case report shows that osteoid osteoma can present in early infancy and can be successfully treated with RFA at this age, however, recurrence after the procedure can occur and close follow-up is recommended.     

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.     

Arthroscopic excision of osteoid osteoma in the posteroinferior portion of the acetabulum

Osteoid osteoma in the acetabulum is very rare and the surgical extirpation is difficult. We present a case of osteoid osteoma in the posteroinferior portion of the acetabulum which was treated with arthroscopic excision. A 29-year-old woman presented with 18 months of pain in the left groin. Computed tomography suggested an osteoid osteoma in the posteroinferior portion of the acetabulum. Arthroscopic excision of the lesion was performed with the aid of image intensifier. The patient’s symptoms disappeared immediately after the surgery. This case report shows that arthroscopic excision is possible in a lesion in the posteroinferior portion in the acetabulum, which previously deemed inaccessible arthroscopically.     

Arthroscopic removal of the osteoid osteoma on the neck of the talus

Juxta-articular osteoid osteomas arising around the ankle are unusual. Tumors arising on the neck of the talus will commonly produce symptoms mimicking monoarticular arthritis or trauma. Patients are usually treated for arthritis or ankle sprain, which often leads to a delay in definitive diagnosis. We present an arthroscopic removal of an osteoid osteoma on the neck of talus, and review the literature.     

Bony sequestrum: a radiologic review

According to a pathological definition, a bony sequestrum is defined as a piece of devitalized bone that has been separated from the surrounding bone during the process of necrosis. However, the radiological definition of a sequestrum is different and refers to an image of calcification visible within a lucent lesion, completely separated from the surrounding bone, without referring to the vascular status and histological nature of the calcified tissue. The term “button sequestrum” has been used in calvarial lesions. The prototype conditions that may present with a bony sequestrum are osteomyelitis and skeletal tuberculosis. Other conditions such as radiation necrosis, eosinophilic granuloma, metastatic carcinoma, primary lymphoma of bone, aggressive fibrous tumors may also manifest as osteolytic lesions containing a sequestrum. In addition, some primary bone tumors produce a matrix that may mineralize and sometimes simulate a bone sequestrum. These include osteoid tumors (osteoid osteoma, osteoblastoma), cartilaginous tumors (chondroma and chondroblastoma), lipomatous tumors (lipoma), and benign fibrous tumors (fibromyxoma, myxoma, and desmoplastic fibroma). Therefore, various conditions may present at imaging as a small area of osteolysis containing central calcifications. However, a careful analysis of the sequestrum as well as the associated clinical and radiological findings often enables to point toward a limited number of conditions.