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X-rays showing a lytic expansile lesion with permeative margins in the distal metaphysis of the radius at initial admission.
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Osteoblastoma-like osteosarcoma, a rare form of osteosarcoma, is a malignant lesion associated with risks of both local recurrence and distant metastasis. The differential diagnosis of osteoblastoma-like osteosarcoma from osteoblastoma and aggressive osteoblastoma remains controversial and challenging. Previous studies suggest that these three type...
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Objective: Many studies have shown that long non-coding RNAs (lncRNAs) are closely related to various cancers. This study aims to explore the roles of lncRNA HOXA11-AS in the development and progression of osteosarcoma (OS).
Methods: The expression levels of HOXA11-AS and miR-125a-5p in tumor tissues and the adjacent tissues were detected by RT-PCR...
Citations
... Their radiographic and histological features are similar, if not identical, the only difference being size. Osteoid osteoma is typically <1 cm and lesions >2 cm will be considered osteoblastoma (Söylemez et al., 2016;Woźniak et al., 2010). In addition, patients with pain that does not worsen at night and who do not respond to NSAIDs -can differentiate osteoblastoma from osteoid osteoma, apart from the difference in size (Lim et al., 2021). ...
Osteoblastoma (OB) is a rare benign osteogenic tumor, primarily found in the axial skeleton and long tubular bones. It accounts for <1% of all primary bone tumors, mainly affecting young adults. Maxillofacial involvement is rare, often manifesting in the mandible. Osteoblastoma's pathogenesis is unclear, with slow growth and varied clinical presentations. Radiologically, it appears as a well-defined, osteolytic lesion with sclerotic rims. The definitive diagnosis relies on histopathology, with immunohistochemistry aiding in challenging cases. Differential diagnoses include fibrous dysplasia, osteoid osteoma, osteomas, cemento-ossifying fibroma, and low-grade osteosarcoma. Surgical excision with safety margins is the standard treatment, while radiotherapy may be considered for certain cases. Prognosis is generally good, but long-term follow-up is essential due to recurrence risks, particularly in aggressive forms. Malignant transformation can occur, emphasizing the importance of careful diagnosis and management.
... Osteoblastomas that exceed 4 cm in size and show prominent periosteal new bone formation may be mistaken for osteosarcomas [1,10]. Histologically, osteosarcomas often have atypical features, including foci of lace-like osteoid deposition, high cellularity, and scattered mitotic figures [1,11]. Tumors exhibiting these features may be misinterpreted as malignant and should be evaluated further [1,10]. ...
... Osteoblastoma-like Osteosarcoma (OBLOS) is a rare variant of osteosarcoma that histologically resembles an osteoblastoma and is considered a rare low-grade variation of osteosarcoma [13]. OBLOS accounts for 1.1% of all osteosarcomas and presents with a tender, persistent ache that can sometimes minimize the range of motion on physical examination [14]. The two histologic features most important in differentiating osteosarcoma from osteoblastoma are tissue maturation and peripheral location. ...
... The lesions often appear as lytic and expansile in radiographs. Irregular ossification or a sclerotic nidus may be observed inside a translucent lesion [14]. is nearly impossible to make with limited tissue, such as needle biopsy and may be impossible even with adequate tissue. ...
Osteoblastoma-like osteosarcoma (OBLOS), is a rare malignant lesion with risks of both local recurrence and distant metastasis. It is considered a rare variant of osteosarcoma. The distinction between (OBLOS), and aggressive osteoblastoma is still debatable and challenging. Based on the initial clinical, radiological, and histological findings, a definitive diagnosis might only sometimes be achievable. On the other hand, the significance of a proper diagnosis must be accomplished because the approach to treatment varies greatly depending on the type of lesion. Sufficient tissue sampling is essential to provide the proper diagnosis. In clinicopathological and radiological discordance cases, a high index of suspicion and significant experience are requirements for an appropriate diagnosis. The OBLOS is categorized as a conventional (high-grade) osteosarcoma in the World Health Organization (WHO) classification system. However, several cases that have been published have been identified as low-grade malignant tumors. There are no precise morphological criteria to discriminate between low-and high-grade lesions. We describe a case of osteoblastoma-like osteosarcoma in an 11-year-old boy involving the right proximal humerus. We provide a brief review of the pertinent literature including diagnosis, differential diagnosis, debatable grading of this type of tumors, management, and prognosis.
... 18 In particular, a rare form of osteosarcoma known as osteoblastoma-like osteosarcoma shares radiographic features with osteoblastoma, posing a further challenge for distinguishing it from osteoblastoma. 19 However, osteosarcoma usually shows more aggressive behavior, such as destruction of cortical bone, tooth resorption, and/or invasion into adjacent soft tissue. 5,20 A sunburst radiographic appearance may also be seen in osteosarcoma. ...
This report presents a rare case of maxillary osteoblastoma in a 17-year-old female. The patient presented with dull pain and facial asymmetry inferior to the left zygoma. An intraoral examination found a painless swelling on the buccal gingival tissue in the left posterior maxilla. Panoramic radiographs and multidetector computed tomographic images revealed an ill-defined, non-corticated, mixed attenuating entity of osseous density located within the left posterior maxilla apical to the left maxillary molars. The entity exhibited a heterogeneous internal structure with a fine granular appearance, and the periphery showed a partial hypo-attenuating rim along the antero-medial aspect. Expansion of the left posterior maxilla accompanied with displacement of the left maxillary sinus floor was noted. External root resorption of the first and second molars was noted, as well as postero-superior displacement of the third molar. The histopathologic diagnosis of the biopsy was osteoblastoma. Complete excision of the tumor was performed.
... Osteoblastoma is a rare tumor, representing about 1% of all bone tumors [2,3]; and its aggressive variant is even rarer. Being its differential features controversial, the diagnosis results challenging [1,5,6]. Classically, AO has a more aggressive local growth and a higher risk of local recurrence than osteoblastoma, but no tendency to metastasize, contrary to osteosarcoma [1,4]. ...
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.
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.
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.
... 72 This variant is frequently diagnosed as an osteoblastoma on needle core biopsies but they follow a more aggressive clinical course. 73 The most relevant morphologic features on which to make a diagnosis of osteosarcoma include infiltration of host bone (permeation), lack of maturation of bone at periphery of the tumor, and sheets of osteoblastic tumor cells without matrix production. 72 ...
Benign bone-forming tumors comprise osteomas, osteoid osteomas, and osteoblastomas. Osteomas affect a wide age range and are usually discovered incidentally. They occur predominantly in the craniofacial skeleton and are classically composed of compact bone. Osteoid osteomas and osteoblastomas are painful lesions occurring in young patients. They are morphologically similar and characterized by FOS gene rearrangement and c-FOS expression at a protein level. Osteoid osteomas are usually smaller than 2 cm in maximum dimension with limited growth potential; osteoblastomas are larger than 2 cm and may be locally aggressive. Histologically both are composed of anastomosing trabeculae of woven bone.
... The welldefined borders of osteoblastomas in CT resemble the histological lack of infiltration at the lesion-host bone interface [38] as seen in the case presented here. OBLOS shares radiological features with both, osteoblastoma and osteosarcoma [19,44]. Ozger et al. in 2016 [44] postulated, OBLOS to be well-or ill-defined, lytic and sharply demarcated on CT and radiographs. ...
... Typical radiographic features of osteosarcoma, like periosteal reaction and/or cortical destruction is a facultative feature in OBLOS. Thinning of the cortex might be present due to the expansile growth [44]. In contrast, OBLOS typically reveals a T1-hypointensity and an intermediate intensity in T2-weighted sequences with heterogeneous contrast enhancement, whereas osteoblastoma shows T1-and T2-iso-to hypointensity with permanent contrast enhancement [44]. ...
... Thinning of the cortex might be present due to the expansile growth [44]. In contrast, OBLOS typically reveals a T1-hypointensity and an intermediate intensity in T2-weighted sequences with heterogeneous contrast enhancement, whereas osteoblastoma shows T1-and T2-iso-to hypointensity with permanent contrast enhancement [44]. Thus, an osteoblastoma at the base of T2 was initially suspected based on radiological examination. ...
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.
... Osteosarcoma, also called osteogenic sarcoma, is a rare, aggressive, and malignant form of tumor, and it is considered to be the most common primary malignant bone tumor [1]. Osteosarcoma accounts for around 20% of all sarcomas, and the majority of osteosarcoma cases are found to be primary and affect adolescents or young adults [2,3]. ...
The diagnosis of craniofacial osteosarcoma can be quite challenging, and the condition often goes unrecognized for a considerable period of time. In this report, we discuss the case of a 21-year old woman who presented with a one-year history of a small swelling over the left maxillary alveolar ridge. Upon further investigation, the histopathological examination showed high-grade chondroblastic osteosarcoma. The option of four cycles of neoadjuvant chemotherapy regimen preoperatively was chosen, and left inferior maxillectomy was performed along with reconstruction with obturator prosthesis. This case highlights the difficulties encountered in such rare cases of craniofacial osteosarcomas both in terms of the delay in the establishment of the diagnosis as well as management protocol. A high index of suspicion is required in cases of craniofacial osteosarcoma and early surgical resection with adequate safety margins is warranted.
... Trial registration: CRD, CRD42019121880. Registered 13 February 2019, https://www.crd.york.ac.uk/PROSPERO Background Osteoblastoma-like osteosarcoma (OBLOS) is a benign pathology, which is a primary bone-forming tumor [1][2][3]. OBLOS is a rare variant of osteosarcoma accounting for approximately 1% of cases overall [4,5]. ...
... The most of reports were case reports [1,8,10,11] or case series and most of those, without statistical analyses, were less convincing [2,12], because of this, little clinical features and outcome patterns were acknowledged. Herein, we reported 1 case from our center and an additional 59 cases from published studies to describe the clinical characteristics of this tumor and to evaluate the prognostic factors and treatment strategy of OBLOS. ...
... Radiologically the lesions were usually lytic with poorly de ned borders and cortical destruction. OBLOS can be high uptake on radionuclide bone imaging [1,2,8,11] and radiolucent or radio-dense [2,5,11]. Ossi cations, a sclerotic nidus, lytic, expansile pattern and periosteal reaction can be present inside the lesion [2,5,8]. ...
Background：
Osteoblastoma-like osteosarcoma is a very rare tumor and the diagnosis and the treatment can be challenging and controversial. Herein, we presented a case occurring in the occipital bone firstly and summarized all of the previously published cases to delineate the clinical characteristics, prognostic factors and treatment strategy of osteoblastoma-like osteosarcoma.
Case presentation:
A 34-year-old man presented with a headache with bitter and dull for 6 months, underwent a suboccipital posterior median approach to remove the lesion without intra-operative complications. Computerized tomography revealed osteogenic bone destruction on the occipital protuberance involving inner and outer table of the skull. Preoperative Magnetic Resonance Venogram revealed that the tumor invades sinus convergence, disappeared sinus convergence, narrowed bilateral transverse sinus, and abundant tumor blood vessels. Re-examination on the day after operation revealed that the post-operative changes of the occipital bone and the tumor were resected completely. The pathologic examination identified the Osteoblastoma-like osteosarcoma. The postoperative course was uneventful. Patient was discharged home 7 days after operation. By four months, re-examination Magnetic Resonance Imaging scan revealed that there was no evidence of recurrence and was not leaded to any problem.
Conclusion:
For patients with presumed osteoblastoma-like osteosarcoma, gross total resection should be recommended. If tolerable, radiotherapy or chemotherapy could be an alternative treatment modality. Patients with areas of conventional osteosarcoma had poor progression-free survival and tumors with metastasis had a poor overall survival. The lung was the most frequently involved regions of metastasis. Trial registration: CRD, CRD42019121880. Registered 13 February 2019, https://www.crd.york.ac.uk/PROSPERO
... In some instances it may be difficult, and occasionally impossible to differentiate osteoblastoma from the so-called osteoblastoma-like osteosarcoma. 7,8 The controversial concept of the histologically labelled "aggressive osteoblastoma" also plays a role in the differential diagnosis of unusual cases. Aggressive osteoblastoma was initially defined as an osteoblastoma with a distinct epithelioid morphology and therefore also referred to as epithelioid osteoblastomas. ...
Osteoblastoma and osteoid osteoma together are the most frequent benign bone-forming tumor, arbitrarily separated by size. In some instances, it can be difficult to differentiate osteoblastoma from osteosarcoma. Following our recent description of FOS gene rearrangement in these tumors, the aim of this study is to evaluate the value of immunohistochemistry in osteoid osteoma, osteoblastoma, and osteosarcoma for diagnostic purposes. A total of 337 cases were tested with antibodies against c-FOS: 84 osteoblastomas, 33 osteoid osteomas, 215 osteosarcomas, and 5 samples of reactive new bone formation. In all, 83% of osteoblastomas and 73% of osteoid osteoma showed significant expression of c-FOS in the osteoblastic tumor cell component. Of the osteosarcomas, 14% showed c-FOS expression, usually focal, and in areas with severe morphologic atypia which were unequivocally malignant: 4% showed more conspicuous expression, but these were negative for FOS gene rearrangement. We conclude that c-FOS immunoreactivity is present in the vast majority of osteoblastoma/osteoid osteoma, whereas its expression is usually focal or patchy, in no more than 14% of osteosarcoma biopsies. Therefore, any bone-forming tumor cases with worrying histologic features would benefit from fluorescence in situ hybridization analysis for FOS gene rearrangement. Our findings highlight the importance of undertaking a thorough assessment of expression patterns of antibodies in the light of morphologic, clinical, and radiologic features.
