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.

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.

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.

Diagnostic and Management Options of Osteoblastoma in the Spine.

BACKGROUND Osteoblastoma is a rare, benign, osteolytic neoplasm commonly found in the spine in early adulthood. Here, we review the clinical characteristics, radiographic findings, and surgical management of patients with spinal osteoblastoma. MATERIAL AND METHODS Thirteen patients with osteoblastoma who underwent surgery at our institute from June 2008 to November 2017 were enrolled in this study. The American Spinal Injury Association (ASIA) impairment scale was used to assess neurological function. All patients were treated with either total excision or intralesional piecemeal excision without postoperative radiotherapy. Clinical efficacy was evaluated by visual analog scale (VAS) scores, the Oswestry Disability Index (ODI) of nerve function, physical and radiographic examinations, bone fusion, and neurologic status. RESULTS The follow-up lasted 23-82 months (average, 43.8 months). The average surgical time was 178.1 minutes (range, 100-230 minutes), with an average intraoperative blood loss of 574 mL (range, 230-1100 mL). Postoperatively, VAS scores decreased from 6.2±1.7 to 0.5±0.7 (P<0.001). The preoperative and final ODI scores were 51.1±7.7 and 22.6±4.9, respectively, reflecting a significant decrease (P<0.001). According to the ASIA classification, 3 patients had grade C, 3 patients had grade D, and 7 patients had grade E disease. Three months postoperatively, 1 patient had grade D and 10 patients had grade E disease; ultimately, all cases were grade E disease. Only 1 patient experienced local recurrence and underwent en bloc marginal resection with postoperative radiotherapy. All patients remained neurologically stable without any major complications. CONCLUSIONS Accurate intraoperative localization with complete resection is the key to preventing recurrence. Aggressive surgical resection can achieve satisfactory clinical and radiographic outcomes.

A rare case of giant osteoblastoma of the sacrum.

BACKGROUND: An osteoblastoma is a rare benign bone tumor characterized by formation of osteoid tissue and primitive bone and occurs more often in men than in women. They are often secondary to an osteoid osteoma and can be located at any site on the skeleton. Lesions generally involve the posterior elements of the spine, such as the pedicle and the lamina. CASE PRESENTATION: This study reports the case of a 25-year-old female who suffered from an osteoblastoma of the right sacrum with repeated swelling and pain in the right lumbosacral region for approximately 6 months. Computed tomography (CT) and magnetic resonance imaging (MRI) of the pelvis revealed a segmented, expansive, multiseptate lesion. Resection with wide margins was performed and a huge cavity of approximately 15â€¯× 8â€¯× 4.4 cm in the right sacrum and pelvis was formed after complete curettage of the tumor. The pathological analysis of the resected tissue was consistent with a benign osteoblastoma. A follow-up was performed 2 years later and the patient was eventually relieved of the pain, the mobility of the right leg was improved and the CT scan demonstrated no evidence of recurrence. CONCLUSION: Osteoblastomas most commonly occur in the spine but rarely also in the sacrum. Large core needle biopsies play an important role in the diagnostics. Intralesional surgery can be performed for treatment of osteoblastomas.

Cystic bone tumors of the foot and ankle.

Bone tumors are relatively rare in the foot and ankle region. Many of them present as cystic lesions on plain films. Due to the relative rarity of these lesions and the complex anatomy of the foot and ankle region, identification of such lesions is often delayed or they get misdiagnosed and mismanaged. This review discusses the most common cystic tumors of the foot and ankle including their radiographic features and principles of management.

Pseudomalignant osteoblastoma of the odontoid process.

INTRODUCTION: The anterior elements of the spine, particularly the odontoid processes, are a rare location for osteoblastomas. Pseudomalignant osteoblastomas are themselves rare histologic types and are also extremely rare in this location. Most osteoblastomas are Enneking stage 2 lesions; less frequently, they can be more aggressive with extra-capsular extension (Enneking stage 3). En bloc resection is recommended for aggressive lesions, but the literature is less clear regarding the approach to stage 2 tumors, particularly those with pseudomalignant histologic features. CASE REPORT: A 6-year-old male child presented with a type III pathologic fracture of the odontoid. The fracture healed but upon 6-month follow-up CT scanning, an expansile lesion was detected. Surgical biopsy revealed an osteoblastoma which was treated with intralesional excision. Meanwhile, the excised specimen showed histological features of a pseudomalignant osteoblastoma. Despite this diagnosis, no further treatment was undertaken. At a 10-year follow-up, the patient was free from pain and had full range of motion of the cervical spine; no recurrence was detected. CONCLUSION: This unique case of odontoid osteoblastoma illustrates that malignant behavior may not be predicted only by the presence of pseudomalignant features on histology.

Giant periosteal aggressive epithelioid osteoblastoma: 21-year-old male presents case in the midshaft of his femur.

We report a rare case of giant periosteal osteoblastoma in the femur of a 21-year-old male. The patient presented with a painful, firm, non-tender mass in his left thigh. The pain was worse at night and was temporarily relieved with NSAIDS. He had no fevers, night sweats, or weight loss. The patient underwent preoperative radiological studies including plain radiographs, MRI, bone scan, and CT scan. An open biopsy was subsequently performed that was consistent with an aggressive, epithelioid osteoblastoma. Pathology demonstrated a neoplasm characterized by cohesive sheets of epithelioid osteoblasts, mixed with areas of conventional osteoblastoma displaying prominent osteoblastic rimming of woven bone trabeculae in a fibrovascular stroma. The patient subsequently underwent resection, cryosurgery, fixation, and bone grafting with cortical strut allografts. At final follow-up, 32 months postoperatively, there was no evidence of local recurrence. The patient had resumed all his normal activities. He could run without pain and had no restrictions with activities. The goal of this case report is to aid professionals in the diagnosis and treatment of highly uncommon aggressive osteoblastomas.

Osteoid osteoma of the temporal bone manifesting as first bite syndrome and a meta-analysis combined with osteoblastoma.

The objectives of this study were to describe a case of osteoid osteoma arising from the temporal bone manifesting only as first bite syndrome as the sole clinical symptom, to perform a meta-analysis of previously reported cases, and to differentiate the clinical characteristics of osteoid osteoma from those of osteoblastoma arising from the temporal bone. In addition to our case, articles addressing osteoid osteoma or osteoblastoma arising from the temporal bone were selected using PubMed, Embase, and the Japan Medical Abstracts Society database (1954 through 2014), with no language preference. The database was searched using the keywords ["osteoid osteoma" OR "osteoblastoma" AND "temporal bone"]. After critical review of 88 studies, 10 cases of osteoid osteoma and 29 cases of osteoblastoma were selected; therefore, including the present case, a total of 40 cases were eligible for qualitative analyses. The mean size of osteoid osteoma was 1.2 cm, which was significantly smaller than that of osteoblastoma (5.1 cm). Radiologically, osteoid osteoma was associated with a lower prevalence of extension into more than two anatomically categorized spaces in comparison with osteoblastoma (P < 0.01). Again, a lower prevalence of erosion of the outer and/or inner tables of the skull in the osteoid osteoma cases was noted (P < 0.05). Conversely, there were no significant differences in the prevalence of representative clinical symptoms, including pain and swelling. According to the present systematic review, osteoid osteoma and osteoblastoma are clinically uniform other than their size or extension.

Aggressive Osteoblastoma in the Maxilla: Unusual Lesion in the Craniofacial Skeleton.

Osteoblastomas are benign bone tumors, which are unusual in the craniofacial skeleton, being most often observed in the axial skeleton and long bones. The most common site in the maxillofacial region is the mandible and the involvement of the maxilla and paranasal sinuses is extremely rare. Although it is a benign lesion, the aggressive variant raises concerns due to its huge local destructive potential and tendency to relapse. In this clinical case, an aggressive osteoblastoma is described in a 7-year-old patient. The lesion was large and fully involved the left maxilla, including the maxillary sinus and the nasal cavity. Recurrent volume increase was observed 2 months following enucleation of the lesion and en bloc resection of the maxillary segment was performed. Histological and immunohistochemical evaluation associated with clinical and imaging findings allowed to define the tumor as an aggressive variant of osteoblastoma and not osteosarcoma, despite the aggressive behavior. The patient recovered well and no relapses were observed after 12 months following maxillary resection.

Osteoblastomas of the spine: a comprehensive review.

Osteoblastomas are primary bone tumors with an affinity for the spine. They typically involve the posterior elements, although extension through the pedicles into the vertebral body is not uncommon. Histologically, they are usually indistinguishable from osteoid osteomas. However, there are different variants of osteoblastomas, with the more aggressive type causing more pronounced bone destruction, soft-tissue infiltration, and epidural extension. A bone scan is the most sensitive radiographic examination used to evaluate osteoblastomas. These osseous neoplasms usually present in the 2nd decade of life with dull aching pain, which is difficult to localize. At times, they can present with a painful scoliosis, which usually resolves if the osteoblastoma is resected in a timely fashion. Neurological manifestations such as radiculopathy or myelopathy do occur as well, most commonly when there is mass effect on nerve roots or the spinal cord itself. The mainstay of treatment involves surgical intervention. Curettage has been a surgical option, although marginal excision or wide en bloc resection are preferred options. Adjuvant radiotherapy and chemotherapy are generally not undertaken, although some have advocated their use after less aggressive surgical maneuvers or with residual tumor. In this manuscript, the authors have aimed to systematically review the literature and to put forth an extensive, comprehensive overview of this rare osseous tumor.

A rare case of osteoblastoma associated to aneurysmal bone cyst of the spine. Case report.

Osteoblastoma is a rare bone tumour. It is occasionally associated with an aneurysmal bone cyst (ABC). Several treatment strategies can be adopted. We report a challenging case of an osteoblastoma associated with ABC of the lumbar spine in a 2-year-old boy. The pathogenesis and the critical management of the disease are discussed.

An Osteoblastoma of the Mandible: A Case Study.

This case study involves a 22-year-old male who experienced moderate pain in the left side of the mandible for two months. He was diagnosed with an osteoblastoma and treated with local excision, curettage and extraction of the involved teeth. Radiographic follow-up indicated that the site healed well. Clinical, radiographic and histopathologic features are discussed. Osteoblastoma requires interdisciplinary care and should be considered in the differential diagnosis of mixed-density lesions detected in the jaws.

Surgical treatment options for aggressive osteoblastoma in the mobile spine.

PURPOSE: Osteoblastoma (OBL) is a benign bone tumor with considerable recurrence potential. Resection is the mainstay for the treatment of Enneking stage 3 (st. 3) OBL. This retrospective study aimed to verify the appropriate surgical strategy for st. 3 lesions in the mobile spine. METHODS: 19 cases of st. 3 OBL was diagnosed between 2001 and 2011. Clinical, radiological, surgical, and follow-up data were analyzed. This series included 14 men and 5 women and the mean age at diagnosis was 30.4 years. The lesions were located in the cervical spine in ten cases, in the thoracic spine in eight, and in the lumbar spine in one. Fourteen patients were surgically treated for the first time (intact cases), and five were referred to us after previous unsuccessful treatments (non-intact cases). RESULTS: Before 2008, 11 patients underwent curettage followed by radiotherapy, including 5 non-intact cases and 6 intact cases. Tumor recurrence was observed in all five non-intact cases and four of the six intact cases. After 2008, eight intact patients underwent intralesional vertebrectomy, including six who underwent piecemeal total vertebrectomy and two who underwent intralesional en bloc vertebrectomy. All the eight patients had embolization before surgery. 18 patients had an average 67.3 months (range 36-148 months) of follow-up. Recurrence was not observed in any of these eight cases with intralesional vertebrectomy. CONCLUSION: Intralesional total vertebrectomy might be an appropriate choice for intact st. 3 OBL spine lesions. More cases with longer follow-up periods should be recruited in the future to better understand the treatment options available for this disease.

Benign bone tumors.

Benign bone lesions are a broad category that demonstrates a spectrum of activities from latent to aggressive. Differentiating the various tumors is important in order to properly determine necessary intervention. This chapter focuses on the presentation, imaging, diagnostic features, and treatment of the most common benign bone tumors in order to help guide diagnosis and management.

Osteogenic tumors of bone.

In this paper we provide an overview of benign and malignant osteogenic bone tumors. We describe the diagnostic features, radiographic findings, and pertinent ancillary studies needed to diagnose these bone-forming lesions. We begin with osteoid osteoma and osteoblastoma, which are histologically bland and eminently benign with rare possible exceptions. On the other end of the behavioral spectrum is osteosarcoma, which encompasses many subtypes ranging from high-grade osteogenic osteosarcoma to less overtly osteogenic lesions such as telangiectatic and small cell osteosarcoma. While classic osteogenic osteosarcoma can be easily recognized by its high grade morphology and formation of extracellular lace-like osteoid, its variants may pose diagnostic dilemmas as their differential diagnoses can include benign, fibrous, and vascular lesions, among others. Recognition of these variants is essential to avoid diagnostic pitfalls. In equivocal cases, some forms of osteosarcoma have shown molecular alterations that may prove diagnostically useful.

Clinical characteristics and treatment options for two types of osteoblastoma in the mobile spine: a retrospective study of 32 cases and outcomes.

PURPOSE: A retrospective study of 32 patients with osteoblastoma (OBL) in the mobile spine was performed to analyze the clinical characteristics of two types of spinal OBL. We also aimed to find influential factors for OBL in the mobile spine. METHODS: Between 2002 and 2011, 32 patients with either conventional osteoblastoma (CO) or aggressive osteoblastoma (AO) in the mobile spine were treated in our center. All patients were treated with either total excision or subtotal excision + postoperative radiotherapy. The mean follow-up was 45.8 (18-128) months. Clinical data and surgery efficacy were analyzed to search for clinical characteristics of two subtypes of spinal OBL and discuss the possible factors influencing relapse. RESULTS: There is significant difference between CO and AO in tumor size (p < 0.0005), preoperative alkaline phosphatase (ALP, p < 0.0005) and intraoperative blood loss (p = 0.013). Multivariate logistic regression was used to find the influential factors for relapse and the results were: preoperative ALP, b = 0.023, p = 0.029; surgery protocol, b = -7.597, p = 0.007; tumor size, ≥3/<3, b = 24.805, p < 0.0005; age, b = 0.054, p = 0.632; and pathology type, b = 1.998, p = 0.34. CONCLUSIONS: Tumor size, preoperative ALP and CT images were helpful for distinguishing AO from CO. The difference in intraoperative blood loss between CO and AO is mainly attributed to the size of the lesion. Preoperative ALP, surgery protocol and tumor size (≥3/<3) were considered to significantly influence relapse of spinal OBL.

Clinical and morphological characteristics of osteoid osteoma and osteoblastoma: a retrospective single-center analysis of 204 patients.

Osteoid osteoma and osteoblastoma are histologically similar, benign bone-forming tumors. In this retrospective study, we aimed to evaluate the natural history; clinical, pathologic, and radiologic findings; and treatment results in 204 patients between 1959 and 2006 in a single institution. According to the World Health Organization's definition, tumors ≤1 cm in diameter were classified as osteoid osteoma, and those ≥2 cm, as osteoblastoma. For tumors between 1 cm and 2 cm, other criteria, such as the bone involved, the site, the presence of a nidus, and presence of peripheral sclerosis, were used for diagnosis. There were 131 patients with osteoid osteoma (93 male, 38 female) and 73 patients with osteoblastoma (40 male, 33 female). The mean age in the osteoid osteoma and osteoblastoma groups was 16.4 ± 7 and 19.6 ± 9.9 years, respectively. The osteoid osteoma cases were mostly localized in the extremities, whereas the osteoblastoma cases involved the vertebral column and sacrum. The nidus size varied between 0.2 and 1.5 cm in osteoid osteoma cases, and the tumor size range was 1.3-10 cm in the osteoblastoma cases. The pain was encountered in 89% of osteoid osteoma and 45% of osteoblastoma patients. Histopathology was similar in both cases. The treatment of choice was conservative surgery for both diagnoses. In conclusion, osteoblastoma is clinically and radiologically more aggressive than osteoid osteoma.

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.

Benign osteoid-producing bone lesions: update on imaging and treatment.

Benign osteoid-producing osseous tumors are frequently encountered in a typical musculoskeletal radiology practice. Enostoses are extremely common, but osteomas, osteoid osteomas, and osteoblastomas are diagnosed less often. A thorough discussion of the typical clinical presentation, histology, imaging findings, treatment and prognosis for each tumor is provided, with particular emphasis on more current imaging techniques and treatments.