The prognostic impact of TERT mutations has been controversial in IDH-wild tumors, particularly in glioblastomas (GBM). The controversy may be attributable to presence of potential confounding factors such as MGMT methylation status or patients’ treatment. This study aimed to evaluate the impact of TERT status on patient outcome in association with various factors in a large series of adult diffuse gliomas. We analyzed a total of 951 adult diffuse gliomas from two cohorts (Cohort 1, n = 758; Cohort 2, n = 193) for IDH1/2, 1p/19q, and TERT promoter status. The combined IDH/TERT classification divided Cohort 1 into four molecular groups with distinct outcomes. The overall survival (OS) was the shortest in IDH wild-type/TERT mutated groups, which mostly consisted of GBMs (P < 0.0001). To investigate the association between TERT mutations and MGMT methylation on survival of patients with GBM, samples from a combined cohort of 453 IDH-wild-type GBM cases treated with radiation and temozolomide were analyzed. A multivariate Cox regression model revealed that the interaction between TERT and MGMT was significant for OS (P = 0.0064). Compared with TERT mutant-MGMT unmethylated GBMs, the hazard ratio (HR) for OS incorporating the interaction was the lowest in the TERT mutant-MGMT methylated GBM (HR, 0.266), followed by the TERT wild-type-MGMT methylated (HR, 0.317) and the TERT wild-type-MGMT unmethylated GBMs (HR, 0.542). Thus, patients with TERT mutant-MGMT unmethylated GBM have the poorest prognosis. Our findings suggest that a combination of IDH, TERT, and MGMT refines the classification of grade II-IV diffuse gliomas.Electronic supplementary materialThe online version of this article (doi:10.1186/s40478-016-0351-2) contains supplementary material, which is available to authorized users.

Autophagy is a dynamic process of protein degradation. Induction of autophagy by temozolomide (TMZ) has been noted in glioma cell lines. Twenty-eight specimens, obtained from 14 patients before and after TMZ treatment, were analyzed to investigate whether induction of autophagy could be detected in surgical specimens by immunohistochemical analysis. Macroautophagy was monitored by immunohistochemical analysis employing anti-light chain 3 isoform B (LC3B) and anti-lysosome-associated membrane protein 1 (LAMP1) antibodies; chaperone-mediated autophagy was monitored by anti-LAMP2A antibody immunostaining. Furthermore, detection of LC3B protein by Western blotting was performed on six specimens obtained from the preserved frozen tissues of three patients. All specimens showed dot-like staining for each immunostain in the cytoplasm of glioma cells, indicating induction of autophagy. LC3B, LAMP1 and LAMP2A immunostains were semiquantitatively scored from 1 to 3 points. Combination of the three scores after TMZ treatment (6.4 ± 1.2) showed a significant increase (P = 0.020) compared to pre-treatment scores (5.2 ± 1.5). Western blotting for LC3B showed increased LC3B-I and LC3B-II expression after TMZ treatment. The present study proved that autophagy monitoring by immunohistochemical staining of surgical specimens was feasible. These results suggest that autophagy is induced by TMZ.

Pleomorphic xanthoastrocytoma (PXA) is a rare astrocytic tumor that usually occurs in the superficial cerebral hemispheres of children and young adults and has a relatively favorable prognosis. We report an unusual case of supratentorial, intraventricular tumor in a 52-year-old man. The tumor was composed of pleomorphic cells, including giant cells, most of which were multinucleated, and small cells. In addition, frequent xanthic changes in the cytoplasm of the tumor cells, and widespread reticulin deposits and lymphocytic infiltrates in the stroma were characteristic features. Large areas of necrosis were also evident. However, mitotic figures were rare (1-2 mitoses per 10 high-power fields). Many tumor cells were positive for GFAP, and a number were positive for neurofilament protein and synaptophysin, indicating their neuronal differentiation. In addition, occasional tumor cells were positive for CD34. p53 protein was entirely negative in the tumor cells. In diagnosing this tumor histopathologically, differentiation between PXA and giant cell glioblastoma (GCG), a rare variant of glioblastoma, was problematic. However, considering the overall histopathological picture, a final diagnosis of PXA with anaplastic features was made. The present case indicates that PXA can occur as an intraventricular tumor, and suggests that in some instances, it would be very difficult to differentiate PXA and GCG histopathologically.

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Background The Delphi consensus statements on the management of germ cell tumors (GCTs) failed to reach agreements on the statement that the cases with 1) pineal and neurohypophyseal bifocal lesion, 2) with diabetes insipidus, and 3) with negative tumor markers can be diagnosed as germinoma without histological verification. To answer this, multicenter retrospective analysis was performed. Methods A questionnaire on clinical findings, histological diagnosis, and details of surgical procedures was sent to 86 neurosurgical and 35 pediatrics departments in Japan. Results Fifty-one institutes reported 132 cases that fulfilled the three criteria. Tissue sampling was performed in 91 cases from pineal (n = 44), neurohypophyseal (n = 32), both (n = 6) and distant (n = 9) lesions. Histological diagnosis was established in 89 cases: pure germinoma or germinoma with syncytiotrophoblastic giant cells in 82 (92.1%) cases, germinoma and mature teratoma in two cases, and granulomatous inflammation in two cases. Histological diagnosis was not established in two cases. Although no tumors other than GCTs were identified, three (3.4%) patients had non-germinomatous GCTs (NGGCTs). None of the patients developed permanent complications after endoscopic or stereotactic biopsy. Thirty-nine patients underwent simultaneous procedure for acute hydrocephalus without permanent complications, and hydrocephalus was controlled in 94.9% of them. Conclusion All patients who fulfilled the three criteria had GCTs or granulomatous inflammation, but not other types of tumors. However, no less than 3.4% of the patients had NGGCTs. Considering the safety and the effects of simultaneous procedures for acute hydrocephalus, biopsy was recommended in such patients.