[BRAF V600E mutation and clinicopathologic characteristics in 250 cases of brain tumors associated with epilepsy]

Objective: To investigate the clinicopathologic characteristics and BRAF V600E mutation of brain tumors associated with epilepsy. Methods: Totally 250 patients with brain tumors associated with epilepsy were included from March 2008 to August 2017 retrospectively at Sanbo Brain Hospital, Capital Medical University.The clinical manifestations, histological features and BRAF V600E mutation results were collected and analyzed. Results: There were 132 males and 118 females, and the male to female ratio was 1.1∶1.0. The age of patients ranged from 2 to 67 years(mean 22 years). The tumors had obvious local space occupying effect on MRI. The temporal lobe was the most common site (44.4%, 111/250). There were 58.4% (146/250) of ganglioglioma (GG), 24.0% (60/250) of dysembryoplastic neuroepithelial tumor (DNT), 12.8% (32/250) of pleomorphic xanthoastrocytoma(PXA), 4.0% (10/250) of angiocentric glioma (AG) and 0.8% (2/250) of papillary glioneuronal tumor (PGNT). Mixed GG, PXA and DNT morphological structures were found in 9 of patients. Among 250 cases, 35 cases were accompanied by focal cortical dysplasia(FCD). BRAF V600E was seen in 43 of 74 (58.1%) GG and 13 of 28 (46.4%) PXA. The most common pathologic grade of GG, DNT, AG and PGNT was WHO I. Some of the tumor cells from GG (34 cases) showed higher proliferative activity (WHO Ⅱ/Ⅲ). Most cases of PXA were WHOⅡand high proliferative activity was seen in nine cases. Conclusions: The association of low-grade glioneuronal tumors with intractable epilepsy was well-recognized. The most common low-grade glioneuronal tumors were GG.GG may occur in any part of the central nervous system, with a predilection for temporal lobe. Each type of low-grade glioneuronal tumors has its own unique histological morphology, but some may show complex features with 2 or 3 mixed components. The occurrence of BRAF V600E mutations in GG is common, and their detection may be valuable for the diagnosis and treatment in GG.

[Abnormality of TOP2A expression and its gene copy number variations in neuroblastic tumors]

Objective: To detect TOP2A protein expression and gene copy number alterations, and to analyze related clinical and pathological implications in pediatric neuroblastic tumors (NT). Methods: Immunohistochemistry was used to detect TOP2A protein expression. Fluorescence in situ hybridization (FISH) was used to detect numerical aberrations of TOP2A. Results: TOP2A protein was expressed in 59.1%(52/88) of cases, which was associated with differentiation (P=0.006), Ki-67 index (P<0.01) and MKI (P=0.001). Twenty-eight cases (35.0%, 28/88) showed TOP2A gene amplification, which was correlated with the age (P<0.01), clinical stage (P=0.028), high risk group (P=0.001), Ki-67 index (P=0.040) and differentiation (P=0.014). Survival analysis showed that TOP2A expression was related to survival rate. Multivariate analyses showed that TOP2A expression was an independent predictor for poor prognosis (P=0.010). Conclusions: More than half of the cases show TOP2A expression, which is more likely associated with NB, high Ki-67 index and high MKI. Cases with TOP2A expression have shorter survivals and poorer prognosis. TOP2A amplification is seen in 35% and likely occurs in patients older than 18 months and at advanced INSS stages (Ⅲ and Ⅳ). As a target of the anthracycline-based adjuvant drugs, TOP2A test can be used to select patient with NT for the therapy.