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.

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.

Multimodal Imaging Evaluation and Clinical Progress of Spinal Osteoblastoma: A Comprehensive Review.

Spinal osteoblastoma is rare clinically, with insidious onset, atypical symptoms, and various imaging manifestations, which can easily lead to misdiagnosis and delayed diagnosis. It can cause severe neurological dysfunction in patients with intermediate to advanced stages and may easily recur after surgery. Imaging examinations such as radiography, computed tomography, magnetic resonance imaging, and positron emission tomography have different value for the diagnosis of spinal osteoblastoma, but they lack specificity. The preferred treatment is surgical resection, which is technically difficult, and in some cases, osteoblastoma cannot be completely removed. New clinical approaches such as radiofrequency ablation, radiotherapy, targeted chemotherapy, and other comprehensive treatments have emerged and are progressing rapidly, but no unified norms have yet been developed. This manuscript provides a systematic review of the literature and provides an extensive and comprehensive review of this rare tumor in terms of multimodality imaging manifestations and clinical progress.

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.

Osteoid Osteoma of Retromolar Trigone: Report of a Rare Case.

Osteoid osteoma is a rare benign bone lesion that is often confused with the osteoblastoma. The osteoid osteoma comprises of 3% of all the primary bone tumours usually found in the long bones and vertebrae with the facial skeleton being the most infrequent site. The lesion usually presents with the swelling and pain that resolves with non-steroidal anti-inflammatory drugs (NSAIDs). Here, we report a case of osteoid osteoma of retromolar trigone, the site which has not been reported in the literature, in a 50-year male patient with a complaint of hard swelling on retromolar trigone associated with the mild intermittent localised pain that aggravated at night and on mastication. Excision of the lesion was carried out with chisel and mallet under local anesthesia with uneventful recovery and no recurrence at the 6 months follow-up. Key Words: Benign, Osteoid osteoma, Retromolar trigone.

Aneurysmal bone cyst and osteoblastoma after neoadjuvant denosumab: histologic spectrum and potential diagnostic pitfalls.

The use of denosumab to treat giant cell tumors of bone (GCT) and other giant cell-containing bone tumors has become more common. While the clinicopathologic features of denosumab-treated giant cell tumors of bone have been well-illustrated, descriptions of other denosumab-treated bone tumors are very limited. Surgical pathology files of two institutions and consultation files from two authors were searched for denosumab-treated aneurysmal bone cysts and denosumab-treated osteoblastomas. Clinicopathologic features were reviewed and analyzed. We identified four patients with denosumab-treated bone tumors other than GCT from our surgical pathology and consultation files, including two aneurysmal bone cysts and two osteoblastomas. All were treated with denosumab for 0.5-7.0 (median 4.5) months. Radiologically, denosumab-treated tumors showed decreased size with increased ossification and mineralization on CT and heterogeneous intermediate to hypointense signal on MRI. Histologically, denosumab-treated aneurysmal bone cyst contained thin, elongated, curvilinear, and anastomosing strands of bone with empty lacunae, while denosumab-treated osteoblastoma showed circumscribed nodules of woven bone lined by small osteoblasts. Denosumab-treated aneurysmal bone cyst and osteoblastoma showed treatment-related morphologic changes that can mimic other bone neoplasms. Their recognition requires correlation with the clinical history of denosumab use and radiologic findings.

Osteoblastoma of the Temporal Bone in a Child.

This report describes osteoblastoma of the temporal bone found on a well-child visit. The relevant clinical, radiographic, and histologic features are described. The tumor was completely resected via a transtemporal approach. The differential diagnosis for these tumors include osteoma, giant cell tumor, histiocytosis, aneurysmal bone cyst and sarcoma. Histologic findings are critical for determining the proper diagnosis.

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.

Tailored surgery on aggressive osteoblastoma involving the cervicothoracic junction: an oncological and spinal stability long-term follow-up.

INTRODUCTION: Aggressive osteoblastoma (AO) represents a rare tumor with borderline features between benign osteoblastoma and osteosarcoma. Having a local aggressive behavior without metastasizing attitude, radical excision is a mainstay treatment. Conversely, spine fusion technique is still debated. We report a rare case of cervicothoracic junction (CTJ) AO and the tailored decision-making process to choose the best treatment. CASE PRESENTATION: A 34-year-old man complaining of neck pain was admitted to our department. Cervicothoracic MRI revealed a well-circumscribed lesion involving C7 left lamina with cortical erosion and mild spinal canal invasion. Additionally, STIR sequences exhibited a bright signal spreading through the posterior third of the C7 and T1 vertebrae which on T1-weighted and T2-weighted sequences appeared isointense and hyperintense, respectively. Therefore, the patient underwent a C7 laminotomy. Histology revealed an aggressive variant of osteoblastoma. Therefore, tumor was classified as AO and surgical management was reconsidered. A combined anterior and posterior approach was recommended to reach oncological radicality and spinal stability. At 6-years follow-up, patient remained neurologically intact without signs of recurrence and/or of instability. DISCUSSION: Due to its rarity and mimicking features, diagnosis of AO results challenging. Due to its aggressive behavior, radical surgery is the mainstay treatment. Conversely, the most suitable fusion technique is still debated. A proper surgical management should be focused on oncological radicality to guarantee the total tumoral removal avoiding progression or recurrences. Similarly, a proper evaluation of the long-term spinal balance should be assessed to avoid developing of spinal deformities or instrumentation failures.

Unusual Osteoblastoma of the First Metatarsal Bone Treated by Total Resection and Fibular Autograft: A Case Report.

CASE: A 25-year-old man presented with progressive pain and swelling of the left foot for 4 years. The images showed a contrast-enhanced mixed lesion (osteolytic and blastic) of the first metatarsal bone with surrounding soft-tissue edema. The differential diagnoses favored chronic osteomyelitis or neoplasia, most likely benign. Histopathology confirmed the diagnosis of osteoblastoma as immature bone trabeculae rimmed by osteoblasts appeared. Then, the patient was successfully treated with wide surgical excision of the first metatarsal bone and reconstruction using a nonvascularized fibular autograft. After 3 years of follow-up, the graft was well incorporated and no recurrence was encountered. CONCLUSION: Osteoblastoma is rare in metatarsals; only 12 cases have been reported. It may have similar clinical and radiological picture to osteomyelitis. Wide surgical excision followed by fibular autograft reconstruction is an effective treatment option.

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.