CT and MRI features of calvarium and skull base osteosarcoma (CSBO)

A case of primary osteosarcoma in the occipital bone: A relatively common tumor in an uncommon location

Osteosarcomas predominantly manifest in the long bones of the extremities, with rare occurrences in the skull. A case involving of a 53-year-old female who presented to the authors' hospital for examination due to dizziness was incidentally found to have an occipital bone mass, which was initially diagnosed as a benign tumor and did not receive sufficient attention. Two years later, owing to tumor enlargement, the patient underwent further evaluation at the same institution, which revealed evidence of occipital bone destruction. Pathological analysis confirmed the diagnosis of osteosarcoma. The patient underwent surgical resection followed by radiotherapy. Despite its infrequency and uncharacteristic initial presentation, skull osteosarcomas should not be overlooked.

The CT and MRI features of benign calvarium and skull base osteoblastoma

OBJECTIVE

We retrospectively reviewed the CT and MRI features of patients with benign osteoblastoma in the calvarium and skull base (CSBOB).

METHODS

Nine cases of pathologically confirmed benign CSBOB were analysed retrospectively. The patients had undergone CT and/or MRI. Tumour location, size, and imaging features were reviewed and recorded.

RESULTS

The patients included four males and five females with a mean age of 27.0 years (age 14-40 years). The tumours were located in the frontal bone in 3 patients, the occipital bone in 3 patients, and in the parietal bone, sphenoid bone, and skull base in 1 patient each. On CT, the tumours measured 5.1 ± 3.3 (1.8-8.4) cm. Seven tumours were shown to have caused expansile bony destruction with an eggshell appearance and varying degrees of calcification or matrix mineralization. Multiple septa were observed in 5 tumours. Intracranial growth was observed in 5 tumours. On MRI, 7 tumours showed heterogeneous hypo- to isointensity on T1WI. Heterogeneous high signal patterns with low signal rims and septa were observed in 6 tumours on T2WI, and 4 showed a fluid-fluid level. On contrast-enhanced imaging, 6 tumours showed peripheral and septal enhancement, and 2 showed the dural tail sign.

CONCLUSIONS

Benign CSBOB is a rare tumour characterized by expansile bony destruction, septa, a sclerotic rim and calcification or matrix mineralization on CT and MRI.

ADVANCES IN KNOWLEDGE

The findings from this study contribute to a better understanding of benign CSBOB and provide valuable imaging features that can aid in its diagnosis and differentiation from other tumours in the calvarium and skull base.

Intelligent Segmentation Medical Assistance System for MRI Images of Osteosarcoma in Developing Countries

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents. It has a high degree of malignancy and a poor prognosis in developing countries. The doctor manually explained that magnetic resonance imaging (MRI) suffers from subjectivity and fatigue limitations. In addition, the structure, shape, and position of osteosarcoma are complicated, and there is a lot of noise in MRI images. Directly inputting the original data set into the automatic segmentation system will bring noise and cause the model's segmentation accuracy to decrease. Therefore, this paper proposes an osteosarcoma MRI image segmentation system based on a deep convolution neural network, which solves the overfitting problem caused by noisy data and improves the generalization performance of the model. Firstly, we use Mean Teacher to optimize the data set. The noise data is put into the second round of training of the model to improve the robustness of the model. Then, we segment the image using a deep separable U-shaped network (SepUNet) and conditional random field (CRF). SepUnet can segment lesion regions of different sizes at multiple scales; CRF further optimizes the boundary. Finally, this article calculates the area of the tumor area, which provides a more intuitive reference for assisting doctors in diagnosis. More than 80000 MRI images of osteosarcoma from three hospitals in China were tested. The results show that the proposed method guarantees the balance of speed, accuracy, and cost under the premise of improving accuracy.

Primary osteosarcoma of the sphenoid wing in a middle-aged woman with extensive intracranial extension: A case report

Primary osteosarcomas involving the base of the skull in middle-aged patients are rare. We describe the case of a 59-year-old Asian woman presenting with lethargy, epistaxis, left maxillary and mandibular pain, and headache. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a large left greater sphenoid wing tumour with extensive local infiltration and intracranial extension. The tumour was diagnosed as osteosarcoma based on histological examination. In this report, we discuss the clinical presentations, radiological features, and imaging differential diagnoses of this case.

Novel circular RNA circATRNL1 accelerates the osteosarcoma aerobic glycolysis through targeting miR-409-3p/LDHA

In recent researches, circular RNAs (circRNAs) have been shown to exert critical functions in osteosarcoma biology. Nevertheless, the contribution of circRNAs to osteosarcoma remains largely unclear. Results indicated that expression of circATRNL1 was higher in osteosarcoma tissues and cells. The high-expression of circATRNL1 was significantly correlated with aggressive features and acted as an independent risk factor for osteosarcoma patients' overall survival. Functionally, our findings demonstrate that circATRNL1 promotes the osteosarcoma aerobic glycolysis in vitro. Mechanistically, circATRNL1 up-regulated the expression level of LDHA, which was also targeted by miR-409-3p. Therefore, circATRNL1 exerted the accelerative roles of osteosarcoma aerobic glycolysis through miR-409-3p/LDHA axis. In conclusion, circATRNL1 promoted osteosarcoma progression by enhancing glycolysis via circATRNL1/miR-409-3p/LDHA axis, which may inspire a novel therapeutic target for osteosarcoma.

Determinants of Survival in Skull Base Osteosarcoma: A National Cancer Database Study

OBJECTIVE

Skull base osteosarcoma is a rare and aggressive tumor that is most commonly treated with primary surgical resection and adjuvant chemoradiation. Using the National Cancer Database, we analyzed demographic and clinical prognosticators for overall survival (OS).

METHODS

The National Cancer Database was queried for cases of histologically confirmed skull base osteosarcoma treated between 2004 and 2015, excluding patients receiving palliation or having <1 month of follow-up. A total of 314 patients treated with surgery alone (n = 82), surgery with adjuvant radiotherapy (n = 35), surgery with chemotherapy (n = 114), or trimodality therapy (n = 56) were identified. The χ² test for categorical variables, Cox proportional hazards models, and Kaplan-Meier log-rank analysis were used to test associations with treatment, OS, and survival time.

RESULTS

None of the studied demographic characteristics (age, sex, race, overall health) and socioeconomic factors (income and average regional education) were associated with OS (none P < 0.05). Treatment modalities also did not show a significant association with OS (none P < 0.05). Certain tumor characteristics showed an association with OS, with fibroblastic and Paget histologic subtypes (each P = 0.003), poorly differentiated tumor grade (P = 0.03), and tumor size >5 cm (P = 0.045) associated with poorer OS.

CONCLUSIONS

Tumor histologic subtype, advanced tumor grade, and greater tumor size are predictors of worse OS in skull base osteosarcoma. No significant differences in OS were identified based on treatment modality, which warrants further investigation.

Second Malignancies after Radiation Therapy: Update on Pathogenesis and Cross-sectional Imaging Findings

A wide spectrum of second cancers occur as late complications of radiation therapy (RT) used to treat various malignancies. In addition to the type and dose of radiation, lifestyle, environmental, and genetic factors are important to the development of second malignancies in cancer survivors. Typically, RT-induced malignancies (RTIMs) are biologically aggressive cancers with a variable period of 5-10 years for hematologic malignancies and 10-60 years for solid tumors between RT and the development of the second cancer. Although carcinomas and leukemias commonly develop after low-dose RT, sarcomas occur in tissues or organs that receive high-dose RT. Angiosarcomas and unclassified pleomorphic sarcomas are the two most common RT-associated sarcomas; other sarcomas include malignant peripheral nerve sheath tumors, leiomyosarcomas, osteosarcomas, chondrosarcomas, and dedifferentiated or pleomorphic liposarcomas. Select RTIMs show tumor genetic characteristics that allow accurate diagnosis. Nearly all cutaneous angiosarcomas after RT for breast cancer and 90% of RT-associated malignant peripheral nerve sheath tumors are characterized by MYC gene amplifications and loss of H3 K27me3 expression, respectively. Classic papillary thyroid carcinomas that develop after RT frequently harbor RET/PTC rearrangements and have a favorable prognosis, despite their advanced stage at patient presentation. Select RTIMs demonstrate characteristic imaging findings and typically develop in the prior radiation field. Imaging is essential to early diagnosis, characterization, localization, and staging of RTIMs. Familiarity of radiologists with the diverse spectrum of RTIMs is essential for early diagnosis and optimal management. An invited commentary by Shapiro is available online. ^©RSNA, 2021.