Objective:The 5th edition of the WHO classification of central nervous system (CNS) tumors in 2021 made significant revisions to the nomenclature and grading system of solitary fibrous tumors (SFT). This study aimed to explore the changes in the grading of CNS SFT and its relationship with clinical pathological features and prognosis.Methods:This study retrospectively reviewed the clinical and pathological data of 82 patients with CNS SFT diagnosed at the First Affiliated Hospital of Fujian Medical University from March 2006 to June 2021, reassessed their grading according to the WHO 5th edition CNS tumor classification, and conducted a comprehensive analysis of their histological morphology, immunohistochemical characteristics, and clinical imaging data.Results:The age of the patients ranged from 21 to 83 years, with a median age of 48 years. Follow-up was completed for 82 patients, during which 10 patients died, 24 recurred, and 5 metastasized. MRI imaging showed that SFT exhibited isointense signals on T1-weighted imaging (T1WI) and complex signals on T2-weighted imaging (T2WI), with signal intensity decreasing as the content of collagen fibers increased. According to the 2021 grading criteria, there was a significant change in the grading of SFT, with the number of grade 1 SFT increasing from 10 cases under the 2016 standard to 39 cases, while the number of grade 2 and 3 SFT decreased accordingly. The 2016 grading system was significantly correlated with the overall survival (OS) of patients ( P=0.009), while the 2021 grading system did not reach statistical significance. Both grading systems were correlated with histological phenotype, Ki-67 index, mitotic figures, and necrosis ( P＜0.05). All cases expressed STAT6, and showed varying degrees of expression of vimentin, CD99, BCL-2, and CD34. The staining intensity of type Ⅳ collagen fibers, as analyzed semi-quantitatively, was correlated with the OS of the patients ( P=0.017). Conclusions:The new grading system for CNS SFT has undergone significant changes, and its association with OS requires further validation. In-depth study of the content and fine structure of collagen fibers in SFT may have important clinical significance for the prognosis assessment and the formulation of treatment plans for patients. Moreover, quantitative analysis of T2WI signal intensity may provide a new method for preoperative preliminary assessment of the collagen fiber content in SFT.

Objective:To evaluate the accuracy of p53 immunohistochemistry for predicting the mutational status of TP53 in gliomas.Methods:A retrospective study was conducted on 242 diffuse gliomas diagnosed at the Department of Pathology, the First Affiliated Hospital of Fujian Medical University, Fuzhou, China from June 2022 to March 2023. All cases underwent next-generation sequencing (NGS) and p53 immunohistochemical staining. The best threshold in the percentage of p53 immunohistochemical expression was assessed as an alternative to testing for TP53 mutation.Results:Among the 242 diffuse gliomas (WHO grade 2-4), 94 cases had a TP53 mutation. The p53 immunohistochemistry results revealed a significantly increased probability of TP53 mutation when the p53 immunohistochemical positivity rate (based on strongly positive cell count) was ≥20% ( P<0.05). The sensitivity and specificity of p53 immunohistochemistry for predicting TP53 gene mutations were 75.6% and 90.4%, respectively. When p53 immunohistochemical stain was totally negative, the probability of TP53 mutation increased significantly, and the mutation ratio of TP53 gene was 6/17 in all negative cases. Conclusions:When the percentage of p53 positive cells (based on strongly positive cell count) in glioma is ≥20%, p53 immunohistochemistry can be used as a reliable alternative method for TP53 mutation detection. When p53 immunohistochemistry is completely negative, the mutation rate of TP53 gene is higher, and further gene sequencing is recommended to determine the mutation status.

Objective:To evaluate the accuracy of p53 immunohistochemistry for predicting the mutational status of TP53 in gliomas.Methods:A retrospective study was conducted on 242 diffuse gliomas diagnosed at the Department of Pathology, the First Affiliated Hospital of Fujian Medical University, Fuzhou, China from June 2022 to March 2023. All cases underwent next-generation sequencing (NGS) and p53 immunohistochemical staining. The best threshold in the percentage of p53 immunohistochemical expression was assessed as an alternative to testing for TP53 mutation.Results:Among the 242 diffuse gliomas (WHO grade 2-4), 94 cases had a TP53 mutation. The p53 immunohistochemistry results revealed a significantly increased probability of TP53 mutation when the p53 immunohistochemical positivity rate (based on strongly positive cell count) was ≥20% ( P<0.05). The sensitivity and specificity of p53 immunohistochemistry for predicting TP53 gene mutations were 75.6% and 90.4%, respectively. When p53 immunohistochemical stain was totally negative, the probability of TP53 mutation increased significantly, and the mutation ratio of TP53 gene was 6/17 in all negative cases. Conclusions:When the percentage of p53 positive cells (based on strongly positive cell count) in glioma is ≥20%, p53 immunohistochemistry can be used as a reliable alternative method for TP53 mutation detection. When p53 immunohistochemistry is completely negative, the mutation rate of TP53 gene is higher, and further gene sequencing is recommended to determine the mutation status.

Objective:The 5th edition of the WHO classification of central nervous system (CNS) tumors in 2021 made significant revisions to the nomenclature and grading system of solitary fibrous tumors (SFT). This study aimed to explore the changes in the grading of CNS SFT and its relationship with clinical pathological features and prognosis.Methods:This study retrospectively reviewed the clinical and pathological data of 82 patients with CNS SFT diagnosed at the First Affiliated Hospital of Fujian Medical University from March 2006 to June 2021, reassessed their grading according to the WHO 5th edition CNS tumor classification, and conducted a comprehensive analysis of their histological morphology, immunohistochemical characteristics, and clinical imaging data.Results:The age of the patients ranged from 21 to 83 years, with a median age of 48 years. Follow-up was completed for 82 patients, during which 10 patients died, 24 recurred, and 5 metastasized. MRI imaging showed that SFT exhibited isointense signals on T1-weighted imaging (T1WI) and complex signals on T2-weighted imaging (T2WI), with signal intensity decreasing as the content of collagen fibers increased. According to the 2021 grading criteria, there was a significant change in the grading of SFT, with the number of grade 1 SFT increasing from 10 cases under the 2016 standard to 39 cases, while the number of grade 2 and 3 SFT decreased accordingly. The 2016 grading system was significantly correlated with the overall survival (OS) of patients ( P=0.009), while the 2021 grading system did not reach statistical significance. Both grading systems were correlated with histological phenotype, Ki-67 index, mitotic figures, and necrosis ( P＜0.05). All cases expressed STAT6, and showed varying degrees of expression of vimentin, CD99, BCL-2, and CD34. The staining intensity of type Ⅳ collagen fibers, as analyzed semi-quantitatively, was correlated with the OS of the patients ( P=0.017). Conclusions:The new grading system for CNS SFT has undergone significant changes, and its association with OS requires further validation. In-depth study of the content and fine structure of collagen fibers in SFT may have important clinical significance for the prognosis assessment and the formulation of treatment plans for patients. Moreover, quantitative analysis of T2WI signal intensity may provide a new method for preoperative preliminary assessment of the collagen fiber content in SFT.