Imaging manifestations of papillary glioneuronal tumors.

To analyse the imaging findings of papillary glioneuronal tumors (PGNTs), in order to improve the accuracy of preoperative diagnosis of this tumor. The clinical and imaging manifestations of 36 cases of PGNT confirmed by pathology were analyzed retrospectively. A total of 17 males and 19 females, averaging 22.47 (± 11.23) years. Initial symptoms included epilepsy in ten, headache in seven, and others in 19 cases. 97.2% (35/36) of the lesions were located in the supratentorial area, and 80.5% (29/36) in the intraventricular or deep white matter adjacent to the lateral ventricles. Twenty-four of the lesions (66.7%) were mixed cystic and solid, four (11.1%) were cystic with mural nodules, four (11.1%) were cystic, and four (11.1%) were solid. Four cases of PGNT of cystic imaging showed a "T2-FLAIR mismatch" sign. 69.4% (25/36) had septations. Nine lesions (25%) were accompanied by edema, and 9 (25%) of the mixed cystic and solid lesions were accompanied by hemorrhage. Among the 18 patients who underwent computed tomography (CT) or susceptibility-weighted imaging (SWI), nine had lesions with calcification. PGNTs mostly manifest as cystic mass with mural nodules or mixed cystic and solid mass in the white matter around the supratentorial ventricle, and the cystic part of the lesion is mostly accompanied by septations. Pure cystic lesions may exhibit the sign of "T2-FLAIR mismatch". PGNT is rarely accompanied by edema but sometimes by calcification and hemorrhage. Patients often present with seizures, headaches, and mass effect symptoms.

Middle temporal gyrus approach to mesial temporal lobe tumours in children.

AIM OF THE STUDY: To assess whether the middle temporal gyrus (MTG) approach to mesial temporal lobe (MTL) tumours is an effective procedure for the treatment of epilepsy in children. CLINICAL RATIONALE FOR THE STUDY: MTL tumours are a common cause of drug-resistant epilepsy in children. There is as yet no consensus regarding their treatment. One possibility is resection via a MTG approach. MATERIAL AND METHODS: We assessed the medical records of patients treated at the Department of Neurosurgery, Children's Memorial Health Institute,Warsaw, Poland between 2002 and 2020. A prospectively maintained database including clinical, laboratory, and radiographic presentation, as well as pre- and post-operative course, was analysed. Patients with at least a one- -year follow-up were included. RESULTS: There were 14 patients aged 4-18 years who underwent a MTG approach for a MTL tumour. All presented with epileptic seizure, and none had neurological deficit on admission to hospital. Median follow-up was 2.5 years. Neuronavigation was used to adjust the approach, localise the temporal horn, and achieve radical resection of the tumour and the hippocampus. Gross total resection was performed in all cases. In most patients, histopathological examination revealed ganglioglioma. One patient had transient aphasia. Two patients developed hemiparesis after surgery, which later improved. One of them also experienced visual disturbances. Acute complications were more frequent in younger patients (p = 0.024). In all cases, MRI confirmed complete resection and there was no tumour recurrence during the follow-up period. 13/14 patients remained seizure-free (Engel class I). CONCLUSIONS AND CLINICAL IMPLICATIONS: The MTG approach to MTL tumours is an effective procedure for the treatment of epilepsy in children. It avoids removal of the lateral temporal lobe and poses only a minor risk of permanent neurological complications.

Unraveling morphology, methylation profiling, and diagnostic challenges in BRAF-Mutant pediatric glial and glioneuronal tumors.

OBJECTIVES: To elucidate the relationship between DNA methylation profiling (DMP) and pathological diagnosis (PD) in pediatric glial and glioneuronal tumors with B-Raf proto-oncogene, serine/threonine kinase (BRAF) mutations, addressing their diagnostic challenges. METHODS: This retrospective study, conducted in Saudi Arabia, analyzed 47 cases from the Children's Brain Tumor Network online database using scanned images, next-generation sequencing data, and methylation profiles processed using the Heidelberg methylation brain tumor classifiers v12.5 and v12.8. The data was last access on 10 November 2023. RESULTS: The highest prevalence of BRAF mutations was observed in pilocytic astrocytoma and ganglioglioma. The DMP was consistent with PD in 23 cases, but discrepancies emerged in others, including diagnostic changes in diffuse leptomeningeal glioneuronal tumor and polymorphous low-grade neuroepithelial tumor of the young. A key inconsistency appeared between a pilocytic astrocytoma MC and a glioneuronal tumor PD. Two high-grade astrocytomas were misclassified as pleomorphic xanthoastrocytomas. Additionally, low variant allelic frequency in gangliogliomas likely contributed to misclassifications as control in 5 cases. CONCLUSION: This study emphasized the importance of integrating DMP with PD in diagnosing pediatric glial and glioneuronal tumors with BRAF mutations. Although DMP offers significant diagnostic insights, its limitations, particularly in cases with low tumor content, necessitate cautious interpretation, as well as its use as a complementary diagnostic tool, rather than a definitive method.