Low-grade central osteosarcoma of the mandible: a case study report

Importance of 3-dimensional imaging in the early diagnosis of chondroblastic osteosarcoma

The aim of this report is to present a case of chondroblastic osteosarcoma located in the right maxillary premolar region of a 17-year-old female patient. The initial clinical presentation and 2-dimensional (2D) radiographic methods proved inadequate for a definitive diagnosis. However, a cone-beam computed tomography scan revealed a hyperdense, heterogeneous lesion in the right maxillary premolar region, exhibiting a characteristic "sun-ray" appearance. To assess soft tissue involvement, a medical computed tomography scan was subsequently conducted. A positron emission tomography scan detected no metastasis or indications of secondary tumors. T1- and T2-weighted magnetic resonance imaging showed signal heterogeneity within the lesion, including areas of low signal intensity at the periphery. A histological examination conducted after an incisional biopsy confirmed the diagnosis of high-grade chondroblastic osteosarcoma. The patient was then referred to an oncology department for chemotherapy before surgery. In conclusion, these findings suggest that early diagnosis using 3-dimensional imaging can detect chondroblastic osteosarcoma in its early stages, such as before metastasis occurs, thereby improving the patient's prognosis.

Maxillary Parosteal Osteosarcoma: Additional case Report and Literature Review of Surface Osteosarcomas

Introduction: Surface osteosarcomas represent around 3-6% of all osteosarcomas, which include the parosteal (low-grade), periosteal (intermediate-grade) and high-grade surface osteosarcomas. The classical location is the femur, followed by tibia and humerus. Parosteal osteosarcoma is the most common type of surface osteosarcoma. To date, 26 cases of parosteal osteosarcoma affecting the jaws have been reported, with most cases following an evolution time of several months to years, clinically favoring a benign osseous or fibro-osseous lesion. Methods: Here, we report a 39-year-old female who was referred presenting a maxillary tumoral mass 5 years ago, clinically diagnosed as osteoma. After clinical, imaginological and histopathological analysis, a diagnosis of parosteal osteosarcoma was made. Conclusion: Thus, parosteal osteosarcoma should also be considered in the differential diagnosis of benign-appearance, bone-forming nodular lesions affecting the jaws.

Malignant tumours mimicking periapical lesions: A report of three cases and literature review

Apical periodontitis shows radiographic signs such as widening of the periodontal ligament and periapical radiolucency, which differ in extent depending on the stage of the lesion. However, other lesions can be associated with or coincidental to the apical region, representing developmental lesions and benign or malignant tumours. This article describes three cases of malignant tumours, a central mucoepidermoid carcinoma (CMEC), a chondroblast osteosarcoma and an osteosarcoma of the jaw (OSJ) that presented as periapical lesions. Endodontists must be aware of unsuccessful treatment, persistent pain, signs of paraesthesia, a rapid growth rate and delayed response to therapy associated with atypical features. Complementary examinations, such as biopsy and computed tomography, can allow the early diagnosis of malignant tumours, leading to a better prognosis and thus increased survival rates and improvement in quality of life.

Dedifferentiated Low-Grade Central Osteosarcoma of the Mandible

We present the first, to our knowledge, case of a dedifferentiated low-grade central osteosarcoma (LCOS) of the mandible. A 48-year-old Japanese woman underwent enucleation under general anesthesia after a diagnosis of ossifying fibroma. At the second recurrence, the pathological diagnosis after biopsy was of sarcoma with MDM2(+) and CDK4(+) immunohistochemical staining results. Hemimandibulotomy, supraomohyoid neck dissection, and free-flap reconstruction with a rectus abdominal flap were performed. A retrospective reevaluation of the first specimen with additional immunohistochemical staining for MDM2 and CDK4 yielded a final diagnosis of dedifferentiated LCOS. The patient showed no recurrence or lung metastasis 3 years after the final surgery.

Fibrous dysplasia imitating malignancy

Fibrous dysplasia is a benign bone disease, presenting as monostotic or polyostotic lesions, or as part of a syndrome (McCune-Albright/Mazabraud). Its clinical course shows a variegated picture and the progression of its growth is unpredictable. In the workup of 39 fibrous dysplasia cases in the cranio-facial area, four cases presented fast growth tendencies, of which two patients with McCune-Albright syndrome showed malignant-like rapid growth. This local aggressive form is extremely rare, and the concept of this issue has not been clearly defined. With regard to the speed of growth a volumetric-time analysis in one of our cases demonstrated a 74 days tumor doubling rate with an exponential growth curve. According to the literature the aggressive form presented extra-cranially mainly at an adult age, whereas its appearance in our cranio-facial patient collective was much younger. Distinguishing nonmalignant and malignant aggressive forms is difficult and highly inconsistent in the literature. We therefore implemented a quantitative growth measure analysis to define aggressive forms based on progression and speed of growth and impartial of type of FD, localization or functional incapacity. Due to our study findings and literature review we state a prevalence of an aggressive form might be possibly about 5 %.

Low-grade central osteosarcoma in proximal humerus: a rare entity

Low-grade central osteosarcoma is a rare subtype of tumor with low-grade malignancy. Currently, wide resection with negative resection margin is the standard treatment for this disease. The role of neoadjuvant chemotherapy in low-grade central osteosarcoma was controversial and was mostly considered for tumors containing high-grade focal areas. Local tumor recurrences often exhibited a tumor with higher histologic grade or differentiation with the potential for metastases. In low-grade central osteosarcoma, timely wide resection after definite diagnosis can result in 5-year survival for almost 90%. However, the relatively nonspecific radiological and pathological findings make diagnosis very difficult. MDM2 and CDK4 are specific and provide sensitive markers for the diagnosis of low-grade central osteosarcoma, helping to differentiate low-grade central osteosarcoma from some benign lesions, including fibrous dysplasia, bone giant cell tumor, and chondrosarcoma. Here, we report the case of a 19-year-old woman with low-grade central osteosarcoma located at the proximal humerus. The affected site was rare, but the sensitive biomarkers CDK4 and MDM2 were positive. The patient recovered well after wide tumor resection following a proximal humerus endoprosthesis replacement. Our case highlighted the management strategies in low-grade central osteosarcoma. Being familiar with radiographic features, understanding the biological characteristics, and mastering diagnostic biomarkers can help oncologists avoid embarrassing situations in treatment when this rare tumor is highly suspected, even when located at an uncommon site. The discussion in this report focuses on radiographic and pathological features, advances of biomarkers that help in differential diagnosis, and current treatment options in low-grade central osteosarcoma.

Low-grade osteosarcoma arising from cemento-ossifying fibroma: a case report

Cemento-ossifying fibromas are benign tumors, and, although cases of an aggressive type have been reported, no cases of cemento-ossifying fibroma transforming into osteosarcoma have been documented previously. Low-grade osteosarcoma is a rare type of primary bone tumor, representing 1%-2% of all osteosarcomas. A 45-year-old female patient was diagnosed with cemento-ossifying fibroma, treated with mass excision several times over a period of two years and eight months, and followed up. After biopsy gathered because of signs of recurrence, she was diagnosed with low-grade osteosarcoma. The patient underwent wide excision, segmental mandibulectomy, and reconstruction with fibula free flap. The aim of this report is to raise awareness of the possibility that cemento-ossifying fibroma can transform into osteosarcoma and of the consequent necessity for careful diagnosis and treatment planning.

Clinical guidelines for the management of craniofacial fibrous dysplasia

Fibrous dysplasia (FD) is a non-malignant condition caused by post-zygotic, activating mutations of the GNAS gene that results in inhibition of the differentiation and proliferation of bone-forming stromal cells and leads to the replacement of normal bone and marrow by fibrous tissue and woven bone. The phenotype is variable and may be isolated to a single skeletal site or multiple sites and sometimes is associated with extraskeletal manifestations in the skin and/or endocrine organs (McCune-Albright syndrome). The clinical behavior and progression of FD may also vary, thereby making the management of this condition difficult with few established clinical guidelines. This paper provides a clinically-focused comprehensive description of craniofacial FD, its natural progression, the components of the diagnostic evaluation and the multi-disciplinary management, and considerations for future research.

Well-differentiated osteosarcoma of the jaw bones: a clinicopathologic study of 15 cases

Well-differentiated osteosarcoma of the jaw bones is rare, and is often confused with a variety of benign fibroosseous lesions. To better understand its clinicopathologic features, we reviewed our experience with 15 cases. The patients included 7 males and 8 females (age range 14 to 66 y; mean 42.8 y). Six of the tumors arose in the mandible, and 9 in the maxilla. Microscopically, the tumors were infiltrative, relatively hypocellular, and consisted of monomorphic, minimally atypical spindle cells that were usually arranged in fascicles. The tumor cells were intimately related to the surfaces of elongated trabeculae of neoplastic woven bone that lacked osteoblastic rimming. Nine patients were treated with wide excision, 2 patients with marginal excision, and 2 patients with excision and radiation therapy. After definitive therapy, there were no reports of recurrence or metastasis over an average follow-up of 34 months (range 1 to 80 mo). Well-differentiated gnathic osteosarcoma is a low-grade malignancy that may be successfully treated with wide local excision. The prognosis in our series was excellent.

Low-grade osteosarcoma of the mandible

Osteosarcoma (OS), a rare malignant bone tumour arising from primitive bone forming mesenchyme, most often arises in the metaphyses of long bones of the extremities. Bone or osteoid formation within the tumour is characteristic of an osteosarcoma. Craniofacial osteosarcoma (CFOS), most often located in the mandible or maxilla, accounts for only 5-13% of all osteosarcomas. In general, OS of the jaw is a high-grade lesion. Low-grade lesions are rare and represent less than 2% of all osteosarcomas reported in the literature. Because of its rarity and well differentiation, Low-grade OS is usually misdiagnosed as a benign lesion. The clinical and radiographic presentation does not correlate well with the subtle histology picture of a low-grade osteosarcoma which makes the diagnosis difficult.