Chronic neck pain in a child: a case of osteoblastoma of the C5 cervical vertebra.

Osteoblastoma is a primary bone-forming tumour that usually occurs in the second decade with an affinity to the posterior elements when found in the spine. Its occurrence in the early first decade is uncommon and often causes a diagnostic dilemma. It usually has a late presentation and the symptoms may be non-specific which may lead the clinician to overlook this particular entity. We present a case of osteoblastoma of the posterior elements of the C5 vertebra in a pre-adolescent child who was diagnosed and successfully managed with surgical resection in a timely fashion that led to favourable recovery postoperatively.

New kids on the block: FOS and FOSB gene.

FOS and FOSB proto-oncogens are involved in a wide variety of tumourigenic processes. FOS and FOSB gene rearrangements are observed in epithelioid haemangioma, pseudomyogenic haemangioendothelioma, osteoid osteoma/osteoblastoma/cementoblastoma and proliferative myositis/fasciitis. In this review, we provide an overview of FOS and FOSB, including their functions and the differences between lesions with known FOS/FOSB gene rearrangements. Additionally, we discuss the use of FOS/FOSB immunohistochemistry as a diagnostic tool for these lesions.

Neonatal osteoblastic tumor with a novel PTBP1::FOSB fusion.

Congenital/neonatal bone neoplasms are extremely rare. We present the case of a patient with a neonatal bone tumor of the fibula that had osteoblastic differentiation and a novel PTBP1::FOSB fusion. FOSB fusions are described in several different tumor types, including osteoid osteoma and osteoblastoma; however, these tumors typically present in the second or third decade of life, with case reports as young as 4 months of age. Our case expands the spectrum of congenital/neonatal bone lesions. The initial radiologic, histologic, and molecular findings supported the decision for close clinical follow-up rather than more aggressive intervention. Since the time of diagnosis, this tumor has undergone radiologic regression without treatment.

Osteoblastoma of the maxilla: A case report and review of the literature.

Osteoblastoma is a benign tumour with aggressive trait usually seen in young males between 10 and 40 years of age. This condition is quite rare in children. Here, we report one such rare osteoblastoma occurring in the maxilla of a 4-year-old boy and discuss the clinical presentation, radiologic and histologic features, and treatment of this patient, and a brief review.

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.

Osteoblastoma em osso zigomático - relato de caso raro / Osteoblastoma in zygomatic bone ­ rare case report

O osteoblastoma é um tumor frequentemente visto em ossos longos, com pouco envolvimento maxilofacial e raramente localizado em osso zigomático. Devido à sua semelhança clínica e histológica com outros tumores ósseos, o osteoblastoma representa um desafio de diagnóstico para o profissional. A ressecção cirúrgica total é recomendada, sendo que a ausência de recidiva se deve ao diagnóstico correto e tratamento adequado. O objetivo deste artigo é relatar o manejo de um paciente com osteoblastoma envolvendo o osso zigomático e realizar uma breve revisão da literatura.

Osteoblastoma is a tumor often seen in long bones, with little maxillofacial involvement and rarely located in zygomatic bone. Due to its clinical and histological similarity with other bone tumors, osteoblastoma represents a diagnostic challenge for the professional. Total surgical resection is recommended, and the absence of recurrence is due to correct diagnosis and adequate treatment. The aim of this article is to report the management of a patient with osteoblastoma involving the zygomatic bone and to carry out a brief review of the literature.

Methylation and copy number profiling: emerging tools to differentiate osteoblastoma from malignant mimics?

Rearrangements of the transcription factors FOS and FOSB have recently been identified as the genetic driver event underlying osteoid osteoma and osteoblastoma. Nuclear overexpression of FOS and FOSB have since then emerged as a reliable surrogate marker despite limitations in specificity and sensitivity. Indeed, osteosarcoma can infrequently show nuclear FOS expression and a small fraction of osteoblastomas seem to arise independent of FOS/FOSB rearrangements. Acid decalcification and tissue preservation are additional factors that can negatively influence immunohistochemical testing and make diagnostic decision-making challenging in individual cases. Particularly aggressive appearing osteoblastomas, also referred to as epithelioid osteoblastomas, and osteoblastoma-like osteosarcoma can be difficult to distinguish, underlining the need for additional markers to support the diagnosis. Methylation and copy number profiling, a technique well established for the classification of brain tumors, might fill this gap. Here, we set out to comprehensively characterize a series of 77 osteoblastomas by immunohistochemistry, fluorescence in-situ hybridization as well as copy number and methylation profiling and compared our findings to histologic mimics. Our results show that osteoblastomas are uniformly characterized by flat copy number profiles that can add certainty in reaching the correct diagnosis. The methylation cluster formed by osteoblastomas, however, so far lacks specificity and can be misleading in individual cases.

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.

Calcaneal Bone Tumors.

Bone tumors of the foot are an uncommon finding. Most tumors are found incidentally on imaging and are benign. Care must be taken although due to the aggressive nature of malignant bone tumors that can occur in the calcaneus. Malignant lesions will more commonly present with symptoms of pain and swelling. Often misdiagnosed as soft tissue injuries, it is critical to be able to diagnose and treat these lesions early. Imaging plays an important role with plain films and advanced imaging. Surgical treatments can range from curettage with grafting to amputation for more aggressive lesions.

Rib Osteoblastoma as a Cause of Neurogenic Thoracic Outlet Syndrome: A Case Report.

BACKGROUND Osteoblastoma is a very rare bone tumor accounting for 1% of all bone tumors. Most of the time it involves the spine and long bones and it involves the ribs very rarely. While osteoblastoma occurrence in the first rib has been reported, causing neurogenic thoracic outlet syndrome (TOS) has never been reported. CASE REPORT A 23-year-old woman presented with a left cervical mass associated with pain and paresthesia in the medial aspect of the left upper extremity and 4th and 5th fingers for the previous 3 months. The patient denied any previous illness or trauma in her history. Physical examination revealed a hard mass in the posterior triangle of the left neck with altered sensation in the left 4th and 5th fingers. The patient was investigated by a chest roentgenogram, nerve conduction study, computer tomography (CT) of the chest, and magnetic resonance image (MRI), as well as incisional biopsy. Although all radiological investigations were suggesting osteochondroma with a differential diagnosis of chondrosarcoma, the incisional biopsy showed osteoblastoma. Radical surgical excision of the lesion followed through a left supraclavicular approach. The patient's preoperative symptoms were relieved completely and there was no recurrence of the tumor at 2 years. CONCLUSIONS Osteoblastoma of the first rib is very rare tumor and to present with TOS is extremely rare. The nonspecific radiological characteristics of the tumor, especially on CT, makes the preoperative certainty of the diagnosis unlikely.

Isolated osteoblastoma of the cuboid bone: A case report and review of the literature.

Osteoblastoma is a relatively rare, benign, bone-forming tumor, commonly observed in the second and third decades of life. Spine and the long tubular bones are the most common sites of involvement. Osteoblastoma is infrequently seen in other sites, including the bones of hand and foot. A rare case of a 35-year-old man that presented an osteoblastoma of the cuboid bone is reported. The patient was treated with surgical resection and grafting. After the intervention, the patient recovered with no clinical and radiological evidence of recurrence after one year of follow-up. Several cases of osteoblastoma-like variant of osteosarcoma of the cuboid have been previously reported, but, to our knowledge, this is the first case of conventional and isolated osteoblastoma involving the cuboid bone reported in the literature.

[Osteoblastoma of the parietal bone of the cranial vault: about a case]. / Ostéoblastome de l'os pariétal de la voûte du crâne: à propos d'un cas.

Osteoblastoma is an uncommon primary bone tumor. Its occurrence in the cranial vault is extremely rare. We here report our first case of right parietal bone osteoblastoma in a 46-year old woman with a history of benign cranial traumas. She reported progressive painful, non-inflammatory right parietal bone swelling. Craniocerebral CT scan showed hyperdense bone lesion with sparing of the internal table of the right parietal bone. The patient first underwent biopsy, then complete resection of the bone lesion with methyl-methacrylic cement cranioplasty. The postoperative course was uneventful. Anatomopathological examination showed osteoblastoma with no sign of malignancy. This study and literature review highlight the clinical manifestation, the radiological and anatomopathological features as well as the management of osteoblastoma of the parietal bone of the cranial vault.

Intracranial bony ball - An ossified variant of meningioma.

An ossified variant of meningioma in the intracranial region is very rare. We report a case of a 28-year-old female who presented with headache for 4 years. Imaging revealed an extra-axial calcified mass in the left parieto-occipital lobe. The differential diagnosis included osteoblastoma both intracranial and periosteal, calcifying pseudotumor of the neural axis, hyperostosis of the cranium, and ossifying fibroma. She underwent excision of the calcified space occupying lesion. Histopathology was suggestive of an ossified meningioma. At the end of 2-year follow-up, she was asymptomatic with no signs of recurrence.

Bone Tumors: Benign Bone Tumors.

Primary benign bone tumors are uncommon and most often affect children and young adults. They typically are detected incidentally on imaging, though some patients present with pain, swelling, or other symptoms. The four main categories of benign bone tumor are: bone-forming (eg, osteoid osteoma, osteoblastoma, fibrous dysplasia, enostosis), cartilage-forming (eg, osteochondroma, enchondroma), connective tissue, and vascular; the latter two are rare. A fifth category is idiopathic (eg, giant cell tumor, aneurysmal bone cyst, simple bone cyst). Osteochondromas are the most common, accounting for 30% to 35% of benign bone tumors. Giant cell tumors account for 20%, osteoblastomas for 14%, and osteoid osteomas for 12%. All others are less common. Diagnosis mainly is via imaging; biopsy rarely is required. Management varies with tumor type, location, symptoms, and risk of recurrence. Some (eg, enchondroma, osteochondroma, fibrous dysplasia, enostosis) typically are asymptomatic, and generally require no intervention. Others (eg, osteoid osteoma, aneurysmal bone cyst, simple bone cyst) can cause symptoms and require percutaneous ablation or surgery. Still others (eg, giant cell tumor, osteoblastoma) can be aggressive and require surgery and other therapies. Malignant transformation is rare for all benign bone tumors, but patients with these tumors should be monitored with serial imaging.

Benign osteoblastoma of the palate: a rare clinical presentation.

Osteoblastoma is a rare, benign type of osteoblastic tumor. It constitutes approximately 1% of all primary bone tumors. Osteoblastoma most commonly affects the long bones; it very rarely affects the jaw bones. Because of its clinical and histological similarity with other bony tumors, such as osteoid osteoma and fibro-osseous lesions, osteoblastoma is a diagnostic challenge. Very few cases of osteoblastoma involving the maxillofacial region have been reported to date. We herein describe a 15-year-old female patient with osteoblastoma that presented as a palatal swelling of 6 months' duration.

Utility of FOS as diagnostic marker for osteoid osteoma and osteoblastoma.

Osteoid osteoma and osteoblastoma are bone-forming tumors shown to harbor FOS (87%) and FOSB (3%) rearrangements. The aim was to evaluate the immunohistochemical expression of FOS and FOSB in these tumors in comparison to other bone tumors, to evaluate the influence of decalcification, and to correlate immunohistochemical findings with the underlying genetic alteration using fluorescence in situ hybridization (FISH). Immunohistochemistry using whole sections was performed on osteoid osteoma (n=23), osteoblastoma (n=22), osteoblastoma-like osteosarcoma (n=3), reactive (n=3), and proliferative (n=11) bone lesions. Immunoreactivity in giant cell tumor of bone (n=74), aneurysmal bone cyst (n=6), chondromyxoid fibroma (n=20), osteosarcoma (n=85), chondroblastoma (n=17), and clear cell chondrosarcoma (n=20) was assessed using tissue micro arrays. Strong nuclear expression of FOS in > 50% of the tumor cells was observed in all osteoid osteomas (22/22), in 57% of osteoblastomas (12/21) and in 3/197 control cases. FOS immunoreactivity disappeared after > 3 days decalcification. FOS rearrangements were present in 94% of osteoid osteomas and osteoblastomas, with a concordance of 86% between FISH and immunohistochemistry. Two osteoblastomas (5%) were positive for FOSB, as opposed to 8/177 control cases. Additional FISH revealed no FOSB rearrangements in these cases. To conclude, in short decalcified biopsies, FOS immunohistochemistry can be used to diagnose osteoid osteoma and osteoblastoma, as overexpression is seen in the majority, being rare in their mimics. FOS immunohistochemistry should not be used after long decalcification. Moreover, low level of focal expression found in other lesions and tissues might cause diagnostic problems, in which case FISH could be employed.

Edema Surrounding Benign Tumors and Tumor-Like Lesions.

OBJECTIVE: To explore the incidence and significance of intra- and extra-osseous edema associated with benign tumors and tumor-like diseases. METHODS: Magnetic resonance imaging (MRI) data from 300 benign osseous tumors and tumor-like diseases diagnosed by pathology were retrospectively reviewed. Borderline tumors, cases associated with pathological fractures, and skull lesions were excluded from the study. Bone marrow and soft tissue edema were defined on T2WI with fat suppression on MRI in all cases. The incidence rate of edema in benign tumors and tumor-like diseases was determined using the χ 2 test. The preoperative diagnoses were reviewed, and the effect of edema on the differential diagnosis of benign and malignant tumors was analyzed. RESULTS: The incidence rate of bone marrow and soft tissue edema associated with benign tumors and tumor-like diseases was 35.7% (107/300), including 84.4% (27/32) Langerhans cell histiocytosis, 86.4% (19/22) osteoblastoma, 93.9% (31/33) osteoid osteoma, and 85.2% (23/27) chondroblastoma cases. There was no statistically significant difference in the incidence of edema among the four diseases (χ 2 = 1.7, P > 0.05). Of 107 cases associated with edema, 49 (45.8%) were misdiagnosed as malignant tumors by MRI preoperatively. CONCLUSION: Bone marrow and soft tissue edema are a common finding associated with benign bone tumors and tumor-like diseases, and they are frequently detected in Langerhans cell histiocytosis, osteoblastoma, osteoid osteoma, and chondroblastoma.

Osteoblastoma in the Distal Humerus of a Cat.

A 7-year-old neutered male domestic shorthair cat was presented with chronic lameness in the right forelimb. A cystic bony lesion was identified in the distal right humerus and amputation was performed. The epiphyseal trabecular bones of the capitulum and trochlea was replaced by a tan to pink, expansile mass that was surrounded by a thin rim of cortical bone. Microscopically, the tumour was composed of a bland, osteoid producing spindle cell population within a well-vascularized fibrous stroma. Radiographical and histological features were consistent with osteoblastoma. Osteoblastoma and the related osteoid osteoma are uncommon, benign osteoblastic tumours that are reported rarely in animals. These tumours should be considered as differential diagnoses for slow growing, cystic bony lesions in cats.