Benign Brain and Spinal Tumors Originating from Bone or Cartilage.

Benign osseocartilaginous tumors of the spine are overall uncommon, representing between 1 and 13% of all primary bone tumors and less than 10% of all spinal tumors. Tumors in this category include osteoblastic lesions such as the related osteoid osteoma and osteoblastoma, and cartilage-forming lesions including osteochondroma, chondroma, and chondroblastoma. Aneurysmal bone cysts, giant cell tumors of bone, and eosinophilic granulomas also comprise benign tumors of the spine arising from bone. There is significant heterogeneity in the epidemiology, molecular biology, imaging features, and optimal treatment of these lesions. For example, osteoid osteoma is characterized by high expression of the cyclooxygenase enzymes, making it amenable to treatment with anti-inflammatory drugs initially, whereas other lesions such as osteoblastoma may require intralesional curettage or en bloc resection sooner. Generally, en bloc resection is preferred when possible to minimize risk of recurrence. Further, some tumors may arise in the setting of syndromic conditions, such as multiple chondromas arising in Ollier disease or Maffucci syndrome, or as part of genetic disorders, such as osteochondromas in the context of hereditary multiple exostosis. These lesions may present with local pain, cause neurological compromise or be discovered incidentally on routine imaging. The Enneking classification and Weinstein-Boriani-Biagini system are routinely used to classify lesions and assist in surgical planning. More novel techniques such as radiofrequency ablation and laser photocoagulation have been applied for the treatment of osteoid osteoma and may have utility in the treatment of other lesion types. A multidisciplinary approach is critical in the management of benign lesions of the spine, and both chemotherapeutic and surgical approaches are routinely used.

The malignant transformation of osteoid osteoma in the cervical spine to high-grade osteosarcoma: a case report and review of literature.

PURPOSE: Osteoid osteoma occasionally occur in the spine, but their malignant transformation is not common. We present an extremely rare case of the malignant transformation of an osteoid osteoma to high-grade osteosarcoma that formed in the pedicle and spread to the lateral mass of the cervical spine. CASE PRESENTATION: We report the case of an 18-year-old man who suffered from neck pain as an initial symptom. The size of the radiolucent lesion was 12 mm in diameter at the time of diagnosis. Intralesional tumour resection and autologous bone grafting were performed. The remaining tumour grew gradually for 40 months after the surgery; therefore, the tumour had grown rapidly till 51 months after the initial diagnosis. At this stage, the tumour size was approximately 6-fold larger than the initial size, and resulted in progressive paraplegia. A biopsy revealed that the tumour had transformed into a high-grade osteosarcoma. Heavy charged particle irradiation was performed to control tumour growth. CONCLUSIONS: There is a possibility of malignant transformation of osteoid osteoma. Patients with osteoid osteoma or osteoblastoma should be carefully observed, especially for recurrent tumours after an intralesional resection.

Large skull osteoblastoma presented as aneurysmal bone cyst (ABC).

Aneurysmal bone cysts (ABCs) are rare benign vascular bony lesions mostly encountered in young patients. These cysts can occur as primary lesions or, less frequently, secondary to other pathologies such as osteoblastomas. Skull ABCs are rare and can extend intracranially, presenting with hydrocephalus and bleeding. Here we illustrate the case of a 9-year-old male who presented with headache, nausea, and vomiting, without neurological deficit. Radiological investigations showed a soap-bubble lesion with mass effect over the right cerebellum. The patient underwent right sub-occipital craniotomy with marginal wide resection of the cystic lesion. The patient had excellent outcomes. The histopathological report was consistent with osteoblastoma with an aneurysmal bone cyst.

Epithelioid osteoblastoma with secondary aneurysmal bone cyst and FOS gene rearrangement.

Epithelioid osteoblastoma, sometimes equated with aggressive osteoblastoma, is a variant of osteoblastoma that typically demonstrates more worrisome imaging and pathological features compared to conventional osteoblastoma. These more aggressive features can overlap with those seen in osteosarcoma, creating a diagnostic challenge for radiologists and pathologists. Recent identification of FOS and FOSB gene rearrangements in osteoid osteoma and osteoblastoma has allowed for greater diagnostic confidence following biopsy, but careful radiological-pathological correlation remains a key component for guiding appropriate management. Although the imaging features of conventional osteoblastoma have been previously described, there are limited examples in the literature of the imaging appearance of epithelioid osteoblastoma, and none with secondary aneurysmal bone cyst. In this case report, we detail the clinical, imaging, and histological characteristics of a proximal femoral epithelioid osteoblastoma which was pathologically confirmed by FOS and FOSB genetic testing. The initial imaging impression favored a malignancy, but when the biopsy results were correlated in a multidisciplinary fashion with the imaging, epithelioid osteoblastoma became the leading diagnosis which was subsequently genetically confirmed. This case emphasizes the value of multidisciplinary radiology-pathology correlation in routine practice.

Osteoblastoma of the Distal Radius.

Osteoblastomas are rare, benign, bone-forming neoplasms that represent less than 1% of all bone tumors and occur mostly in people aged 10 to 30 years. In long bones, the metadiaphyseal region tends to be most commonly affected. However, to the best of our knowledge, only 11 cases have been reported to occur in the distal radius. We present the clinical, radiological, and histopathological findings of an osteoblastoma of the right distal radius in a 42-year-old woman for whom an open excisional biopsy with nidus removal comprised the treatment and produced a good outcome.

Surgical treatment scenario for osteoblastoma of the pelvis: Long-term follow-up results.

BACKGROUND: The aim of this study was to evaluate the results of different treatments for pelvic Osteoblastoma (OB). METHODS: We retrospectively evaluated 34 patients affected by primary pelvic OB from 3 oncologic referral centers. Patients with a minimum follow-up of 24 months were included. Local recurrence (LR) rate and complications were recorded. RESULTS: The primary treatment was radio-frequency ablation (RFA) in 4 patients (11.8%), curettage (ILC) in 21 (61.7%) and resection (EBR) in 9 (26.5%). Mean follow-up was 8.9 years (SD ± 6.6). Local recurrence free survival (LRFS) rate after primary surgery was 79.4% at 3 and 5 years. In details, LRFS rate at 3 and 5 years was 50.0% in RFA, 81.0% in ILC and 88.9% in EBR. Post-operative complications occurred in 6/34 patients (17.7%), in particular after EBR. CONCLUSIONS: RFA is the least invasive technique to treat OB but with high LR rate. Thus, it should be reserved to very small lesions. ILC is a suitable treatment for stage II OB. For stage III OB, EBR is the treatment of choice, despite an increased risk of complications. For selected stage III OB (relatively small, periacetabular area) ILC might be considered.

Paediatric fronto-orbital osteoblastoma: case report.

Osteoblastoma is a rare benign bone tumour. It represents 1% of all primary bone tumours. Common locations are the vertebral column and long bones of the extremities. Although well documented in craniofacial locations, only occasional case reports describe orbital involvement. The authors present a case of a fronto-orbital osteoblastoma which posed a significant diagnostic dilemma. Despite early local recurrence, the molecular findings were supportive of a benign lesion.

Significant Improvement After Surgery for a Symptomatic Osteoblastoma in a Patient with Camurati-Engelmann Disease: Case Report and Literature Review.

Camurati-Engelmann disease (CED) is a rare, progressive diaphyseal dysplasia characterized as diaphyseal hyperostosis and sclerosis of the long bones. Corticosteroids, bisphosphonates, and losartan have been reported to be effective systemic medications used to reduce CED symptoms. There are no reports of osteoblastoma in patients with CED, and osteoblastoma in the distal radius is rare. We present a patient diagnosed with CED, based on radiological and histological examinations, at 11 years old. At 22 years old, she experienced severe pain in her right forearm and was treated with bisphosphonate, losartan, and prednisolone; however, the pain continued. An expansive and sclerotic lesion at the distal radius was observed on radiography. A follow-up plain radiograph indicated that the lesion was growing. Fluorodeoxyglucose positron emission tomography revealed solitary, intense radiotracer uptake, and a biopsy and surgical resection were performed due to suspected malignancy. Pathologic analysis showed anastomosing bony trabeculae rimmed by osteoblasts observed in a loose fibrovascular stroma. The lesion was diagnosed as an osteoblastoma. Following bone excision and artificial bone grafting, the patient's severe pain almost completely disappeared. At final follow-up, no evidence of osteoblastoma recurrence was noted. To our knowledge, this is the first case report of osteoblastoma arising in a patient with CED. Bone excision and artificial bone grafting may be a treatment option for local symptomatic osteoblastoma in patients with CED.

Surgical Strategy of Pediatric Benign Sacral Tumors.

BACKGROUND: Primary benign osseous tumors and tumor-like lesions at the sacrum are rare in the pediatric population and exact surgical strategy is still unclear. In this study, we evaluate the outcome for pediatric patients with benign tumors and tumor-like lesions at the sacrum who were receiving surgical treatment according to our proposed surgical strategy and classification. METHODS: We analyzed 49 pediatric patients with sacral benign tumors or tumor-like lesions aged 18 years and below from 2005 to 2018. There were 23 men and 26 women with a mean age of 14.0±3.8 years. Nineteen patients had giant cell tumors (GCTs), 9 aneurysmal bone cysts, 5 osteoblastomas, 5 neurogenic tumors, 3 hemangiomas, 3 teratomas, 2 Langerhans cell histiocytosis, 1 chondroblastoma, 1 fibrous dysplasia, and 1 GCT of tendon sheath. We proposed our surgical plan and surgical classification for pediatric patients with sacral benign tumors or tumor-like lesions. RESULTS: The mean follow-up duration was 6.2 years (range, 1.0 to 18.9 y). GCTs (39%, 19/49) and primary aneurysmal bone cysts (18%, 9/49) are the top 2 common histologic types. Preoperative selective arterial embolization (SAE) was performed in 12 cases and 24 patients received intraoperative aortic balloon occlusion (ABO) as the preoperative surgical plan. Furthermore, according to tumor location at the sacrum, we classified surgical excision of sacral benign tumors and tumor-like lesions into 3 types. Fourteen cases were classified as type I, 27 as type II, 3 as type III, and 5 patients with neurogenic tumors cannot be classified into this surgical classification. Ten patients had wound complications. Two had femoral artery thrombosis because of ABO application. One had mechanical failure. Rate of local recurrence was 16%. Seven patients with GCTs and 1 with neurogenic tumor had local recurrence. No patient died of disease at the last follow-up. For the assessment of neurological function, the rate of neurological dysfunction was 12% (6/49). Four cases had urinary incontinence, 3 fecal incontinence, and 3 had bowel obstruction. Next, univariate analysis for influence of preoperative SAE and intraoperative ABO on complications demonstrated that both of them exerted no significant influence on the occurrence of oncological and nononcological complications. CONCLUSIONS: The proposed surgical strategy can provide an excellent therapeutic effect for pediatric benign tumors and tumor-like lesions at the sacrum. Preoperative SAE and intraoperative ABO can safeguard pediatric patients with high vascularity of benign tumor at the sacrum during the operation. LEVEL OF EVIDENCE: Level IV.

Laryngeal Osteoblastoma: Unusual Location in Arytenoid Cartilage.

ABSTRACT: Osteoblastoma is a benign bone tumor with a slow growing and local aggressive nature. This tumor type is usually localized in the cervical vertebra and rarely involves laryngeal cartilage structures. Very few osteoblastoma cases have been reported in the literature. Here we present laryngeal osteoblastoma originating from arytenoid cartilage in a patient with a history of cordectomy due to glottic squamous cell carcinoma.

Osteoblastoma of the mandible in a male patient: a case report.

Osteoblastoma is a rare benign osteoblastic tumor accounting for less than 1% of all bone tumors; approximately 10% to 12% of cases occur in the maxillofacial skeleton. This case report describes the clinical, imaging, and histopathologic findings of an atypical osteoblastoma occurring in the mandible of a 60-year-old man. The characteristics of the lesion and the differential diagnosis from other bone pathoses are reviewed.

MRI patterns indicate treatment success and tumor relapse following radiofrequency ablation of osteoblastoma.

Purpose: To explore the typical magnetic resonance imaging (MRI) pattern of osteoblastoma (OB) after radiofrequency ablation (RFA) treatment and to identify signs indicating treatment success or relapse.Materials and methods: Forty-four follow-up MRI examinations of 15 patients with OB who had undergone 19 RFA procedures were analyzed retrospectively. An early follow-up group (1-4 months after RFA) and a late follow-up group (8-131 months after RFA) were established. The groups were further subdivided according to treatment success. Images were analyzed for the presence of central nidus enhancement (CNE), peripheral nidus enhancement (PNE), perifocal bone marrow edema (PBME) and fatty nidus conversion (FNC).Results: The early follow-up MRI image from every patient in the treatment success group exhibited a target-like appearance with negative CNE and positive PNE or PBME. PNE and PBME were observed in 93% and 71% of the early follow-up images, respectively. A target-like appearance was observed in 25% of the late follow-up images, and PNE and PBME were each observed in 20% of these images. FNC was not observed in the early follow-up images, but was seen in 55% of the late follow-up images. All three MRI images of the patients exhibiting clinical recurrence demonstrated strong CNE, PNE and extensive PMBE, which was in contrast to the images of the patients exhibiting treatment success.Conclusion: A target-like appearance of OB in early follow-up MRI examination indicates treatment success. PNE and PBME typically reduce over time and can lead to FNC in successfully treated patients. CNE recurrence, PNE and extensive PBME are signs of relapse.

A complex histopathological challenge: suspicion of an osteoblastoma-like osteosarcoma arising from the second thoracic vertebra in a cat.

BACKGROUND: Reports of osteoblastic tumours are limited to a few case reports in veterinary medicine. Osteoblastoma-like osteosarcoma has been accepted by the World Health Organization as an intermediate form between an osteosarcoma and osteoblastoma. This type of tumour indicates an osteosarcoma, that may resemble osteoblastoma clinically, histologically, and radiologically and have the capability for metastasis. Osteoblastoma-like osteosarcoma has not been described in veterinary medicine so far. CASE PRESENTATION: An eight-year old cat was presented due to progressive ataxia and paraparesis of the pelvic limbs. Imaging confirmed a well-defined, extradural mass originating from the spinous process of the second thoracic vertebra (T2) leading to severe compression of the spinal cord. Decompressive cytoreduction was achieved by removal of the mass after dorsal laminectomy of T1. After recovering from an acute worsening 3.5 weeks after surgery, the cat had an improved neurological status and the dorsal compression was resolved at follow-up 8 months later. A focal contrast enhancing lesion was still evident at the base of T2 spinous process and lung metastasis was additionally suspected. Based on histopathological, radiographic, and clinical features, an "osteoblastoma-like osteosarcoma" was suspected. CONCLUSIONS: To the best of our knowledge, this is the first description of this tumour in veterinary medicine. In addition, this case report highlights the difficulty in the diagnosis and definition of osseous neoplasia in cats and provides a literature review.

Recurrent lumbar-origin osteoblastoma treated with multiple surgery and carbon ion radiotherapy: a case report.

BACKGROUND: Although osteoblastoma is an uncommon benign bone tumor, it sometimes behaves in a locally aggressive fashion. We herein report a case of recurrent lumbar spine osteoblastoma that was treated by repeated surgery and carbon ion radiotherapy. CASE PRESENTATION: A 13-year-old Japanese girl presented with left side lumbar pain. Computed tomography and magnetic resonance imaging of the lumbar spine demonstrated a tumorous lesion in the left side pedicle of L4. Although gross total resection of the mass, including the nidus, was performed in the initial surgery, recurrence was observed repeatedly in the short term and the pathological diagnosis of all of the resected tumors was conventional osteoblastoma. We finally performed carbon ion radiotherapy after the patient's 3rd palliative operation, and achieved a good outcome. No further recurrence has been observed in 10 years of follow-up. CONCLUSION: We performed carbon ion radiotherapy for a case of recurrent spinal osteoblastoma and achieved a good outcome without recurrence at 10 years after carbon ion radiotherapy treatment. To the best of our knowledge, this is the first case of osteoblastoma that was treated with carbon ion radiotherapy after multiple surgeries.

Percutaneous cryoablation of osteoblastoma in the proximal femur.

A 37-year-old man presented with a 2-year history of left hip pain. Pretherapeutic imaging demonstrated a 4 cm osteoblastoma located in the intertrochanteric region of the proximal femur, surrounded by extensive bone marrow edema. After multidisciplinary meeting, percutaneous cryoablation was decided and performed under computed tomography guidance using three cryoprobes to match the exact size and shape of the tumor, resulting in complete resolution of symptoms. Magnetic resonance imaging follow-up demonstrated resolution of the bone marrow edema pattern and ingrowth of fat at the periphery of the ablation zone consistent with long-term healing of the tumor.

Surgical Excision of Thoracic Osteoblastoma with Secondary Aneurysmal Bone Cyst from a 12-Year-Old Child.

INTRODUCTION: Osteoblastoma is a primary benign tumour which commonly presents in the younger population during the second decade of life. However, more aggressive osteoblastomas may present with features of aneurysmal bone cyst, and these can occur at uncommon locations. CASE PRESENTATION: We report the case of a 12-year-old child having an osteoblastoma on the left side of T11 with secondary aneurysmal bone cyst presenting with neurological deficits and myelopathic symptoms. Surgical debulking of the lesion with decompression laminectomy and posterior instrumentation of the spine was performed. The child is currently recovering well with improvement of neurological deficits. DISCUSSION/CONCLUSION: Osteoblastoma with aneurysmal bone cyst of the thoracic spine is a rare condition with few reports in the literature, and surgical intervention with complete excision has been demonstrated here with recovery of neurological function.

Aggressive Osteoblastoma Involving the Navicular Bone of Foot: A Rare Tumor in a Unique Location.

Aggressive osteoblastoma (AO) is a rare variant of osteoblastoma characterized histologically by epithelioid osteoblasts and clinically by local recurrences if not excised completely. Aggressive osteoblastoma has been described in various unusual sites; however, based on our search of the literature, involvement of the tarsal navicular has not been previously described. Herein, we report what we believe to be the first case of aggressive osteoblastoma involving the tarsal navicular in a 35-year-old woman. The tumor showed osteoid surrounded by epithelioid cells along with numerous osteoclastic giant cells. Absence of necrosis, mitosis, and infiltration into the surrounding native bone helped rule out the possibility of low-grade osteosarcoma.

Percutaneous Image-Guided Cryoablation of Osteoblastoma.

OBJECTIVE. The aim of this observational study was to assess safety and clinical outcomes of percutaneous image-guided cryoablation (CA) to treat osteoblastomas (OBs) at various osseous sites. MATERIALS AND METHODS. A retrospective search was performed to identify patients presenting with painful OBs who underwent CA at the University Hospitals of Strasbourg between March 2007 and December 2018. Ten patients (seven men, three women; median age, 21 years old) were identified and included. Medical records were reviewed to assess complications and clinical outcomes. RESULTS. Median OB diameter was 16.5 mm (range, 16-28 mm). OBs were located in the spine (n = 7), calcaneus (n = 1), fibula (n = 1), and third metacarpal bone (n = 1). In 90% of cases (n = 9), one or more critical structures were within 1 cm of the OB (median distance, 5 mm; range, 2-8 mm), thus requiring extensive protective measures. Technical success was achieved in all cases. Two (20%) immediate neural complications were noted. One major complication was consistent with a permanent sensory deficit of the arm. One minor complication was consistent with a transient right Horner syndrome, which completely resolved after 48 hours with high-dose steroids. Median clinical follow-up was 12 months. Primary clinical success was 100% and 78% at 1 and 12 months of follow-up, respectively, with two patients presenting with recurring pain. CONCLUSION. Percutaneous image-guided CA represents an effective therapeutic option for patients affected by painful OBs; the safety profile of the procedure is acceptable as long as comprehensive protective measures are deployed in light of the frequent close proximity of critical structures.

European multicentre study on technical success and long-term clinical outcome of radiofrequency ablation for the treatment of spinal osteoid osteomas and osteoblastomas.

PURPOSE: To evaluate technical success and long-term outcome of CT-guided radiofrequency ablation (RFA) of spinal osteoid osteomas (OO) and osteoblastomas (OB) in six different European centres. METHODS: Eighty-seven patients with spinal OO (77) or OB (10) were treated with CT-guided RFA, after three-dimensional CT-guided access planning. Patient's long-term outcome was assessed by clinical examination and questionnaire-based evaluation including 10-point visual analogue scales (VAS) regarding the effect of RFA on severity of pain and limitations of daily activities. Clinical success was defined as a reduction of > 30% in the VAS score and patient's satisfaction. RESULTS: Overall, RFA was technically successful in 82/87 cases (94.3%) with no major complications; clinical success was achieved in 78/87 cases (89.7%). The OO/OB were localized in the cervical (n = 9/3), the thoracic (n = 27/1), the lumbar (n = 29/4), and the sacral spine (n = 12/2). A decrease in severity of pain after RFA was observed in 86/87 patients (98.9%) with a persistent mean reduction of overall pain score from 8.04 ± 0.96 to 1.46 ± 1.95 (p < 0.001) after a median follow-up time of 29.35 ± 35.59 months. VAS scores significantly decreased for limitations of both daily (5.70 ± 2.73 to 0.67 ± 1.61, p < 0.001) and sports activities (6.40 ± 2.58 to 0.67 ± 1.61, p < 0.001). CONCLUSION: In a multicentric setting, this trial proves RFA to be a safe and efficient method to treat spinal OO/OB and should be regarded as first-line therapy after interdisciplinary case discussion.

Magnetic resonance-guided focused ultrasound surgery treatment of non-spinal intra-articular osteoblastoma: feasibility, safety, and outcomes in a single-center retrospective analysis.

Background: Interventional radiology, thanks to its low invasiveness and possibility to reduce the average time for the patients to come back to their normal activity, is becoming more and more promising and diffused in multiple fields. Employed without needles, MRgFUS is probably the less invasive techniques among the ones belonging to the field of interventional radiology. Purpose: To evaluate safety and effectiveness of MRgFUS in the treatment of a rare and benign, though disabling, bone lesion: intra-articular osteoblastoma. Materials and methods: A retrospective study was carried out on 6 patients (mean, 21 years) treated in the last 2 years with MRgFUS for symptomatic, histologically proved intra-articular osteoblastoma. The main inclusion criterion was the presence of a good acoustic window. The procedures consisted in MR-guided ablation, using high intensity ultrasound beams focused on the target lesion. Spinal anesthesia or peripheral nerve block was used. Clinical (based on pain and functional scales) and imaging follow-up studies were performed up to 1 year after treatment. Complications were recorded. Multiple linear regression and analysis of variance were used to assess correlations. Results: All the procedures were technically successful; no complications were observed. Painful symptomatology decreased of 88% at 6 months and 98% at 12 months (p < 0.0001), and was associated to functional improvement (p = 0.002). MRI and CT controls showed disappearance of all signs of disease and bone inflammation with a marked tendency to bone healing. Conclusion: This study shows the safety and effectiveness of MRgFUS in the treatment of intra-articular osteoblastoma with a good acoustic window.