Osteoid osteoma. Distant, periarticular, and subarticular lesions as a cause of knee pain

Osteoid osteoma, a benign osteoblastic tumour comprised of osteoid and atypical bone, is a well-known entity. However, clinical diagnosis may be delayed, especially when the pain is referred to a nearby joint. This paper reports a series of 11 cases occurring in physically active patients in whom the diagnosis was delayed because of pain referral to the knee. The mean duration from the onset of symptoms to diagnosis of osteoid osteoma was 20 months (range 3 to 48 months). Review of these 11 lesions indicates that they can be classified on the basis of their anatomical location: (a) distant to the knee; (b) periarticular; or (c) subarticular (intraarticular). It should be noted that initially only 5 of the 11 cases displayed characteristic x-ray findings; in the remaining 6 cases, diagnosis was dependent on positive 99mTc radionuclide bone scans, tomograms, and computerised tomography scans. Of the 9 patients who underwent surgical resection of their lesions, all had complete relief of symptoms and all continued to be asymptomatic at follow-up evaluations.     

Intra-articular osteoid osteoma: diagnostic imaging in three cases

PURPOSE: To report our experience pertaining to three cases of intra-articular osteoid osteoma assessed by means of integrated imaging and review of literature. MATERIALS AND METHODS: Medical records, radiologic and nuclear medicine findings pertaining to three cases of intra-articular osteoid osteoma were retrospectively evaluated and compared with those of surgery. All the patients (2 males, one female; age range 8-38 ys) affected by intra-articular osteoid osteoma respectively of the elbow, tibio-talar joint and hip were evaluated by means of radiographic examination and Magnetic Resonance Imaging (MRI). SE T1-w and T2-w, GRE T2*-w, GRE 3D T1-w and STIR pulse sequences were used and axial, coronal and sagittal images were acquired. Two patients underwent CT scan. One patient underwent skeletal scintigraphy. All the patients underwent surgery. RESULTS: In 2 out of 3 cases plain radiography allowed the radiologist to suspect the presence of the lesion. In the remaining one, plain radiography failed to detect both the nidus and the perilesional osteosclerosis; nevertheless, a small osteochondral erosion of the humeral condyle suggested the presence of joint inflammation, thus leading to further investigation. CT scan well depicted the presence of the nidus and, in one case, the presence of joint effusion. MRI was always able to detect the nidus, which presented as lesion of low to intermediate signal in T1-w images, low signal in the T2-w images in one patient and high signal in the remaining two; in these latter STIR images showed high intensity nidus and edema of neighbouring cancellous bone. Furthermore, in all patients MRI clearly depicted joint effusion. Skeletal scintigraphy demonstrated both the lesion and the inflammatory involvement of neighbouring soft tissue. In all patients histologic specimen confirmed the diagnosis of osteoid osteoma with joint inflammation and synovitis. CONCLUSIONS: According to our results and literature data the pre-surgical diagnosis of osteoid osteoma is very difficult to achieve. Indeed, only the combination of clinical information and radiologic and nuclear medicine findings enables the radiologist to make the right diagnosis.     

骨样骨瘤的影像学诊断

目的分析骨样骨瘤的X线、CT及MRI表现,探讨其影像学特征。方法搜集经临床及病理证实的骨样骨瘤23例,男19例,女4例。所有病例均行X线检查,其中同时行CT检查者19例,行MR检查者7例,3种检查都进行者6例。分析骨样骨瘤的X线、CT和MRI表现,及其对瘤巢和瘤巢周围改变的显示能力,总结其特征性的影像学表现。结果23例病灶均显示一直径0.2～2.1cm大小不等的圆形或椭圆形瘤巢,边界清楚,边缘骨质不同程度硬化,骨膜反应,骨髓腔及软组织水肿或关节腔积液。24例X线平片17例显示瘤巢,19例行CT检查者均清晰显示瘤巢,7例行MR检查者5例可显示瘤巢,2例需结合X线及CT检查方能肯定诊断。X线、CT及MR对瘤巢的显示率分别为73.9%(17/23)、100%(19/19)及71.4%(5/7)。结论瘤巢是骨样骨瘤的特征性表现,CT检查是诊断骨样骨瘤最准确的方法,X线检查是诊断骨样骨瘤的重要方法,MR检查对显示瘤巢周围骨髓、软组织及关节腔情况非常敏感,仅凭X线或MR的表现易造成误诊、漏诊。     

Osteoid osteoma mimicking chronic arthritis. Diagnosis by bone scintigraphy

The case of a patient with osteoid osteoma of the heel is presented. The patient was misdiagnosed and treated for four years as having arthritis. Osteoid osteoma was diagnosed by 99mTc-MDP bone scan that was performed for the evaluation of the arthritis. Plain radiography and magnetic resonance imaging (MRI) were negative for signs of arthritis. However, MRI when reevaluated after positive bone scintigraphy, was found positive for osteoid osteoma. This case underscores the value of bone scintigraphy for the diagnosis of osteoid osteoma.     

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.     

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.     

MR增强扫描在骨样骨瘤诊断中的临床价值

目的分析骨样骨瘤的X线、CT、MRI的影像表现,总结其影像学特征,比较不种影像学检查方法的诊断价值,优化检查,提高对骨样骨瘤的诊断及鉴别诊断能力。方法对我院经手术或穿刺病理证实的32例骨样骨瘤的影像学表现进行回顾性分析。男23例,女9例,男女之比2.61;年龄1.6~42岁,平均年龄9岁。13例同时行X线、CT、MRI检查,26例行X检查,21例行CT检查,20例行MRI检查,8例增强。结果32例骨样骨瘤中,有24例出现大小不一的圆形或椭圆形瘤巢,直径为0.28^-2.22cm,瘤巢周围伴有不同程度的骨质硬化。X线对瘤巢显示率为35%(9/26),4例瘤巢中心出现钙化;CT对瘤巢显示率为90%(19/21),出现钙化者16例,8例显示“血管沟征”;MRI平扫对瘤巢显示率为55%(11/20),增强MRI对瘤巢的显示率为100%(8/8)。20例MRI检查均显示不同程度的骨髓水肿。结论瘤巢是确诊骨样骨瘤的关键,MRI增强扫描对瘤巢的显示率不亚于CT,增强MRI检查在一定程度上能够准确地诊断骨样骨瘤,不用暴露于放射线就可定位瘤巢。     

骨样骨瘤的影像学诊断

目的 分析骨样骨瘤的X线、CT和MRI表现。方法 搜集经手术病理证实的骨样骨瘤48例，其中男33例，女15例。所有病例均行X线检查，其中同时行CT检查者32例，行MR检查者10例，3种检查方法都进行者8例。分析骨样骨瘤在X线、CT和MRI上的表现及其对瘤巢和瘤巢周围改变的显示能力。结果 48例病灶均表现为一圆形或卵圆形的透亮区，直径为0．4～1．7cm，平均9．7cm，其周围有不同程度的骨质硬化。10例行MR检查者均可见瘤巢周围的软组织、骨髓水肿或关节腔积液。48例X线平片仅37例显示瘤巢，32例行CT检查者均清楚显示瘤巢，X线和CT对瘤巢显示率分别为77％(37／48)和100％(32／32)。10例MR检查者均可作出正确诊断，其中8例能直接判断出瘤巢，另2例需对照平片或CT才能肯定。结论 瘤巢是确诊骨样骨瘤的关键，X线平片仍然是诊断骨样骨瘤的重要检查方法，CT是显示瘤巢的最佳方法，MRI能敏感地显示瘤巢周围骨髓内及软组织的炎性水肿，但可能造成误诊，结合平片或CT可作出准确诊断。     

Percutaneous resection under computed tomography guidance of osteoid osteoma. Mid-term follow-up of 38 cases]

PURPOSE: To evaluate the mid-term outcome following CT-guided percutaneous resection of osteoid osteoma. MATERIALS AND METHODS: 38 patients who had been treated by CT-guided percutaneous resection were included. The mean follow-up of 3.7 years. Early and mid-term outcome and histology were analyzed. RESULTS: Histological samples were adequate in 92% of cases and a diagnosis of osteoid osteoma was confirmed in 73.7% of cases. In 6 cases, the lesion was not an osteoid osteoma: 2 mucoid cysts, 1 benign fibrous dysplasia, 1 fibromucoid lesion, 1 focal osteochondritis, 1 osteomyelitis. Cure was achieved in 84.2% of patients. Minor transient complications occurred in 23.7% of cases. The most serious complications included: 1 intramuscular hematoma, 2 femoral fractures, and 1 case of S. aureus osteomyelitis. CONCLUSION: This study confirms that CT-guided percutaneous resection of osteoid osteomas is effective and shows that other small lesions can also be treated using this technique.     

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.     

Intraarticular osteoid osteoma: sonographic findings in three patients with radiographic, CT, and MR imaging correlation.

OBJECTIVE: Intraarticular osteoid osteoma often has subtle radiographic findings and nonspecific clinical features; further diagnostic workup of unexplained joint pain may involve musculoskeletal sonography. We describe the sonographic features of intraarticular osteoid osteoma in three consecutive patients with radiographic, CT, and MR imaging correlation. CONCLUSION: The sonographic findings of painful cortical irregularity and focal synovitis should raise the possibility of intraarticular osteoid osteoma, prompting the search for characteristic findings on correlative imaging studies.     

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 femoral neck mistaken as a synovial herniation pit

A 36-year-old man presented with 1 year of atraumatic left lateral thigh, groin, and hip pain, and imaging consistent with the diagnosis of femoroacetabular impingement and a labral tear. Imaging concurrently demonstrated a synovial herniation pit. The patient underwent hip arthroscopy, which included femoroplasty, acetabuloplasty, labral debridement, and synovectomy. His pain persisted and further workup confirmed an osteoid osteoma that was mimicking a synovial herniation pit. The osteoid osteoma was treated with radiofrequency ablation. At 18 months follow-up, the patient reported complete resolution of his symptoms. We present the case to highlight distinguishing imaging and clinical findings of these similar-appearing lesions. While neither condition is particularly rare individually, the misidentification of osteoid osteoma as a synovial herniation pit is a unique feature of this case that lead to the patient''s protracted clinical course.     

关节镜下治疗关节内骨样骨瘤7例临床报道

目的:探讨关节内骨样骨瘤的诊断和关节镜手术治疗经验。方法:回顾性研究我所于2006年3月～2009年6月手术治疗的7例关节内骨样骨瘤患者。患者平均年龄22.4(11～32)岁。术前均进行薄层CT检查确定诊断和进行手术定位。治疗采用关节镜下定位肿瘤位置,刮勺取出瘤巢。结果:从出现临床症状到确定诊断之间的平均时间为26个月(18～36个月)。术后平均随访时间19个月,患者症状较术前明显改善,表现为VAS评分下降,无复发,疼痛缓解,活动范围正常等。结论:关节内的骨样骨瘤由于不典型的临床症状和平片表现常常导致确诊时间延长。采用关节镜治疗关节内的骨样骨瘤是一种安全有效的方法。     

X线平片和CT诊断骨样骨瘤的能力:64层CT后处理的价值

目的:分析骨样骨瘤的X线和CT表现,探讨64层CT对骨样骨瘤的诊断价值.方法:经手术病理证实的骨样骨瘤19例,男13例,女6例,年龄12～44岁,平均21.5岁.所有病例均行X线检查,同时行CT检查者12例,其中行64层CT检查者4例.分析骨样骨瘤的X线和CT表现,分析2种检查方法对瘤巢和瘤巢周围改变的显示能力.结果:19例病灶均表现为一圆形或卵圆形透亮区,直径0.4～1.7cm(平均10.2cm),其周围有不同程度的骨质硬化,5例周围软组织肿胀.19例中X线平片显示瘤巢14例,12例行CT检查者均清楚显示瘤巢,X线和CT对瘤巢的显示率分别为73.7% (14/19)和100% (12/12).结论:X线平片是诊断骨样骨瘤的重要检查方法,64层CT结合其后处理技术对发现瘤巢和正确诊断骨样骨瘤有重要价值.     

Role of radionuclide imaging in osteoid osteoma.

Radiophosphate bone scans readily disclosed osteoid osteomas in 20 symptomatic patients, including nine patients whose radiographic findings had been negative. In five of the nine patients adjuvant radiogallium imaging was performed, and four showed a disproportionately low uptake relative to radiophosphate. When this occurs, osteoid osteoma can be distinguished from subacute osteomyelitis, which is particularly helpful if the radiograph is equivocal. Radiophosphate bone imaging's generally accepted excellent sensitivity in disclosing obscure symptom-producing focal bone disorders makes it the screening procedure of choice, especially if osteoid osteoma is considered in the differential diagnosis. Only abnormal areas need to be radiographed to add specificity and more precise delineation.     

骨样骨瘤的X线和CT表现

目的 :分析骨样骨瘤的X线和CT表现。方法 :搜集经手术病理证实的骨样骨瘤 2 3例。所有病例均行X线和CT检查 ,分析影像表现特征及其对瘤巢及瘤巢周围改变的显示能力。结果 :2 3例病灶均表现为一圆形或卵圆形的透亮区 ,直径 0 .4～ 1.7cm ,平均 0 .98cm ,其周围有不同程度的骨质硬化。X线和CT对瘤巢显示率分别为 78.3 %( 18/2 3 )和 10 0 %( 2 3 /2 3 )。结论 :瘤巢是确诊骨样骨瘤的关键 ,X线平片是诊断骨样骨瘤的重要检查方法 ,CT是显示瘤巢的最佳方法。     

骨样骨瘤的影像学诊断:X线平片与CT常规横断位及MPR比较

目的:比较常规X线平片、多层螺旋CT常规横断位及多平面重组(multi-planar reformation,MPR)在骨样骨瘤诊断中的价值。方法:回顾性分析41例骨样骨瘤病人在X线平片、CT常规横断位及MPR图像上的表现及其对瘤巢及瘤巢内钙化显示能力。结果:41例病灶均表现为一圆形或卵圆形的透亮区,其周围有不同程度的骨质硬化。41例中仅8例在X线平片上能显示瘤巢,瘤巢显示率为19.5%(8/41);所有检查者均清楚显示瘤巢周围骨质硬化,但均不能显示瘤巢内钙化;41例CT横断位图像及MPR图像均能清楚显示瘤巢,18例CT横断位图像能显示瘤巢内钙化,30例病人在MPR图像能显示瘤巢内钙化;横断位CT图像和MPR对瘤巢内钙化显示率分别为43.9%(18/41)和73.2%(30/41)。结论:瘤巢是确诊骨样骨瘤的关键,CT是显示瘤巢的重要检查方法,MPR图像是显示瘤巢内钙化的最佳方法,有助于做出准确诊断。     

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.     

骨样骨瘤的影像诊断

目的探讨骨样骨瘤的X线、CT与MR表现。方法搜集我院2006—2007年经手术病理证实的骨样骨瘤20例,其中男性12例,女性8例,年龄11~37岁,平均年龄24岁。所有病例均行X线检查,其中行CT检查者6例,行MR检查者8例。分析上述3种影像检查对骨样骨瘤瘤巢的显示率。结果在常规X线检查中20例病灶均表现为一圆形或卵圆形的透亮区,直径>5~16 mm,周围可见不同程度的骨质硬化;其中16例可以看到瘤巢,显示率为80%;6例经CT薄层扫描均可清楚显示瘤巢,显示率为100%;8例行MR检查,其中6例可显示瘤巢,并可见瘤巢周围的软组织肿胀,瘤巢显示率为75%。结论瘤巢是确诊骨样骨瘤的关键。常规X线是诊断骨样骨瘤的首先检查方法,CT是显示瘤巢最可靠的方法,MR显示瘤巢不如CT敏感,但却可以清楚的显示瘤巢周围的软组织肿胀情况。