TERT promoter mutation status is necessary and sufficient to diagnose IDH-wildtype diffuse astrocytic glioma with molecular features of glioblastoma.

The Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy (cIMPACT-NOW) update 3 recommends that histologic grade II and III IDH-wildtype diffuse astrocytic gliomas that harbor EGFR amplification, the combination of whole chromosome 7 gain and whole chromosome 10 loss (7 + /10 -), or TERT promoter (pTERT) mutations should be considered as glioblastomas (GBM), World Health Organization grade IV. In this retrospective study, we examined the utility of molecular classification based on pTERT status and copy-number alterations (CNAs) in IDH-wildtype lower grade gliomas (LGGs, grade II, and III). The impact on survival was evaluated for the pTERT mutation and CNAs, including EGFR gain/amplification, PTEN loss, CDKN2A homozygous deletion, and PDGFRA gain/amplification. We analyzed 46 patients with IDH-wildtype/pTERT-mutant (mut) LGGs and 85 with IDH-wildtype/pTERT-wildtype LGGs. EGFR amplification and a combination of EGFR gain and PTEN loss (EGFR + /PTEN -) were significantly more frequent in pTERT-mut patients (p < 0.0001). Cox regression analysis showed that the pTERT mutation was a significant predictor of poor prognosis (hazard ratio [HR] 2.79, 95% confidence interval [CI] 1.55-4.89, p = 0.0008), but neither EGFR amplification nor EGFR + /PTEN - was an independent prognostic factor in IDH-wildtype LGGs. PDGFRA gain/amplification was a significant poor prognostic factor in IDH-wildtype/pTERT-wildtype LGGs (HR 2.44, 95% CI 1.09-5.27, p = 0.03, Cox regression analysis). The IDH-wildtype LGGs with either pTERT-mut or PDGFRA amplification were mostly clustered with GBM by DNA methylation analysis. Thus, our study suggests that analysis of pTERT mutation status is necessary and sufficient to diagnose IDH-wildtype diffuse astrocytic gliomas with molecular features of glioblastoma. The PDGFRA status may help further delineate IDH-wildtype/pTERT-wildtype LGGs. Methylation profiling showed that IDH-wildtype LGGs without molecular features of GBM were a heterogeneous group of tumors. Some of them did not fall into existing categories and had significantly better prognoses than those clustered with GBM.

Malignant transformation of pleomorphic xanthoastrocytoma and differential diagnosis: case report.

BACKGROUND: Pleomorphic xanthoastrocytoma (PXA) is a rare astrocytic glioma, characterized by large pleomorphic and frequently multinucleated cells, spindle and lipidized cells, a dense pericellular reticulin network, and numerous eosinophilic granular bodies according to the grade II glial tumor standards of the World Health Organization's (WHO) 2016 guidelines. PXA rarely transforms into anaplastic PXA or glioblastoma (GBM) and anaplastic PXA, classified as WHO grade III, has a more aggressive clinical behavior with poorer prognosis than PXA. CASE PRESENTATION: Here we describe an unusual case of PXA in a 19-year-old woman, first admitted with headache and a mass in the left temporal lobe in 2005 that was removed. Twelve years later, she returned with left temporal headache, diplopia and tinnitus. A local tumor recurrence was found, and a second resection was performed. The specimen showed highly malignant findings, such as necrosis, microvascular proliferation, and multiple mitoses. The integrated diagnosis was made as high grade glioma, probably derived from PXA. Immunohistochemical (IHC) stains were positive for oligo2, and approximately 21% positive for Ki-67, while negative for CD34, IDH1 R132H. INI1 and ATRX were retained. As the histological classification was glioblastoma, the patient received GBM-appropriate chemotherapy and radiation therapy and outpatient follow-ups have demonstrated no obvious symptoms for 1 year after surgery. Additional molecular analyses found BRAF V600E mutations in both resections, supporting the idea that the recurrent tumor had derived from PXA. CONCLUSIONS: This case highlights the complexities of differential diagnosis based on the World Health Organization's 2016 guidelines. More integrated criteria to differentiate anaplastic PXA from GBM and epithelioid GBM, combined with genetic screening results, might be needed.

Biopolymer monolith for protein purification.

Porous glycopolymers, "glycomonoliths", were prepared by radical polymerization based on polymerization-induced phase separation with an acrylamide derivative of α-mannose, acrylamide and cross-linker in order to investigate protein adsorption and separation. The porous structure was induced by a porogenic alcohol. The pore diameter and surface area were controlled by the type of alcohol. The protein adsorption was measured in both batch and continuous flow systems. The glycomonoliths showed specific interaction with the sugar recognition protein of concanavalin A, and non-specific interaction to other proteins was negligible. The amount of protein adsorption to the materials was determined by the sugar density and the composition of the glycomonoliths. Fundamental knowledge regarding the glycomonoliths for protein separation was obtained.

Intractable epilepsy due to a rosette-forming glioneuronal tumor with a dysembryoplastic neuroepithelial background.

A rosette-forming glioneuronal tumor (RGNT) was initially reported as an infratentorial tumor that comprised both small neurocytic rosettes and astrocytic components. However, a few studies have reported supratentorial RGNTs arising in the cerebral hemispheres. Here, we report an unusual case involving a 9-year-old boy with a supratentorial RGNT who presented with intractable epilepsy and behavioral changes. Brain MRI revealed a well-circumscribed space-occupying lesion with septae in the right inferomedial parietal lobe. Electroencephalography showed multifocal spikes over the right frontal, temporal and parietal regions. The seizure frequency decreased dramatically after tumorectomy. Histopathological examination revealed prominent neurocytic rosette formation appearing with the specific glioneuronal element of a dysembryoplastic neuroepithelial tumor (DNT). Although the pathogenesis has not been elucidated, a supratentorial RGNT presenting with epilepsy may exhibit a rosette component, which is the major feature of this tumor, against the background of a specific glioneuronal element mimicking DNT. However, RGNT arising in regions other than the fourth ventricle is rare, and the pathogenesis of epilepsy due to RGNT has not been fully elucidated. Further clinical and histological studies are required to understand the pathology underlying epilepsy caused by RGNT.

Indicators of the need for insulin treatment and the effect of treatment for gestational diabetes on pregnancy outcomes in Japan.

This study assessed indicators of the need for insulin therapy and the effect of treatment on pregnancy outcomes in Japanese patients with gestational diabetes mellitus (GDM). All patients diagnosed with GDM were hospitalized for three days. Plasma glucose profiles in patients under strict dietary management and the characteristics of GDM patients with high daily glucose levels were investigated. Patients who failed to achieve glycemic targets were treated with insulin. Indicators of the need for insulin treatment were investigated. Pregnancy outcomes in patients prescribed dietary management and patients prescribed insulin treatment were compared. The study included 112 patients with GDM. GDM patients with high daily glucose levels in the hospital exhibited significantly higher 1-h and 2-h plasma glucose levels in oral glucose tolerance tests (OGTTs) at diagnosis. In our hospital, 102 GDM patients with singleton pregnancies were followed until delivery; 32 (31.3%) were treated with insulin. Univariate analysis identified significant associations of insulin requirement with family history of diabetes and with 1-h and 2-h OGTT values at diagnosis. Multivariate analysis showed that the 1-h OGTT plasma glucose level at diagnosis was an independent predictor of the need for insulin. In perinatal outcomes, insulin treatment was associated with low birth weight.

A multi-institutional study designed by members of Tokyo Guidelines (TG) Core Meeting to elucidate the clinical characteristics and pathogenesis of acute cholangitis after bilioenteric anastomosis and biliary stent insertion with a focus on biliary obstruction: Role of transient hepatic attenuation difference (THAD) and pneumobilia in improving TG diagnostic performance.

BACKGROUND/PURPOSE: The aim of this study was to clarify the clinical characteristics of acute cholangitis (AC) after bilioenteric anastomosis and stent-related AC in a multi-institutional retrospective study, and validate the TG18 diagnostic performance for various type of cholangitis. METHODS: We retrospectively reviewed 1079 AC patients during 2020, at 16 Tokyo Guidelines 18 (TG 18) Core Meeting institutions. Of these, the post-biliary reconstruction associated AC (PBR-AC), stent-associated AC (S-AC) and common AC (C-AC) were 228, 307, and 544, respectively. The characteristics of each AC were compared, and the TG18 diagnostic performance of each was evaluated. RESULTS: The PBR-AC group showed significantly milder biliary stasis compared to the C-AC group. Using TG18 criteria, definitive diagnosis rate in the PBR-AC group was significantly lower than that in the C-AC group (59.6% vs. 79.6%, p < .001) because of significantly lower prevalence of TG 18 imaging findings and milder bile stasis. In the S-AC group, the bile stasis was also milder, but definitive-diagnostic rate was significantly higher (95.1%) compared to the C-AC group. The incidence of transient hepatic attenuation difference (THAD) and pneumobilia were more frequent in PBR-AC than that in C-AC. The definitive-diagnostic rate of PBR-AC (59.6%-78.1%) and total cohort (79.6%-85.3%) were significantly improved when newly adding these items to TG18 diagnostic imaging findings. CONCLUSIONS: The diagnostic rate of PBR-AC using TG18 is low, but adding THAD and pneumobilia to TG imaging criteria may improve TG diagnostic performance.

Long-term surgical outcomes of patients with type 1 autoimmune pancreatitis.

BACKGROUND: Although pancreatectomy has sometimes been performed for patients with autoimmune pancreatitis (AIP) presenting atypical radiologic findings under the diagnosis of pancreatobiliary malignancy, the long-term surgical outcome of these patients had not yet been fully elucidated. METHODS: The long-term surgical outcomes of 13 patients with pathologically diagnosed type 1 AIP with immunohistochemical staining for immunoglobulin G4 (IgG4) were retrospectively compared with those of 34 patients with conventional chronic pancreatitis to evaluate the residual pancreatic function. RESULTS: A definite relapse of AIP in terms of the clinical manifestations and diagnostic imaging was not found in any of the patients, although one patient experienced an attack of acute pancreatitis caused by pancreatic stones, and stricture of the hepaticojejunostomy occurred in one patient. The overall body weight decreased significantly more in patients with AIP than in patients with conventional chronic pancreatitis (p < 0.05); however, there was no difference in the preoperative nondiabetic patients. Refractory diarrhea occurred in only one patient with AIP. The cumulative new-onset rates of diabetes mellitus of the ten patients with AIP and 24 patients with conventional chronic pancreatitis at 5 years after the surgery were 32.5 and 26.1 %, respectively (p = 0.70). CONCLUSIONS: Careful long-term follow-up is needed for patients undergoing pancreatectomy for type 1 AIP because remnant pancreatic function can deteriorate as severely as that of patients who undergo pancreatectomy for conventional chronic pancreatitis. In the present series, however, there were few definite manifestations indicating relapse or the persistent existence of AIP.

Effects of switching from liraglutide to semaglutide or dulaglutide in patients with type 2 diabetes: A randomized controlled trial.

INTRODUCTION: Few studies have examined the effects of glucagon-like peptide-1 receptor agonist switching, particularly in Japanese patients. Therefore, we aimed to investigate the effects of switching from liraglutide to semaglutide or dulaglutide on blood glucose, body weight, and the occurrence of adverse effects in clinical practice. MATERIALS AND METHODS: This was an open-label, prospective, randomized, parallel-group controlled trial. Patients with type 2 diabetes treated with liraglutide (0.6 or 0.9 mg) at Yokosuka Kyosai Hospital in Japan were recruited from September 2020 to March 2022 and, after obtaining informed consent, randomly assigned to the semaglutide or dulaglutide group (1:1). Changes in the glycated hemoglobin level from baseline to weeks 8, 16, and 26 were evaluated post-treatment. RESULTS: Initially, 32 participants were enrolled, of whom 30 completed the study. Glycemic control was significantly better in the semaglutide group than in the dulaglutide group (-0.42 ± 0.49% vs -0.00 ± 0.34%, P = 0.0120). Body weight significantly decreased in the semaglutide group (-2.6 ± 3.6 kg, P = 0.0153), whereas no change was observed in the dulaglutide group (-0.1 ± 2.7 kg, P = 0.8432). We found a significant difference in body weight between the groups (P = 0.0469). The proportion of participants who reported adverse events was 75.0% and 18.8% in the semaglutide and dulaglutide groups, respectively. One patient in the semaglutide group had difficulty continuing treatment due to severe vomiting and weight loss. CONCLUSIONS: Switching from once-daily liraglutide to once-weekly semaglutide 0.5 mg significantly improved glycemic control and body weight compared with switching to once-weekly dulaglutide 0.75 mg.

Sclerosing meningioma with a large peritumoral cyst: Case report.

Meningioma morphology is diverse. Although unlisted in the WHO classification, sclerosing meningioma is a rare variation featuring an extremely low signal intensity on MRI T2-weighted imaging. About 50 cases of sclerosing meningiomas, including spinal tumors, have been reported; however, cases with an accompanying large peritumoral cyst remain unreported. Here, we first report a rare case of sclerosing meningioma with a large peritumoral cyst and review relevant literature.

Single-incision laparoscopic enucleation for pancreatic insulinoma with preoperative nasopancreatic stent placement: A case report.

INTRODUCTION AND IMPORTANCE: Most insulinomas are benign and solitary, with a tumor diameter less than 2 cm; therefore, laparoscopic enucleation, which is a minimally invasive procedure that can preserve the pancreatic parenchyma, is considered an optimal procedure. The key to enucleation is to avoid injury to the main pancreatic duct (MPD). Herein, we present a case in which single-incision laparoscopic enucleation (SILE) was performed for insulinomas, with preoperative nasopancreatic stent (NPS) placement. CASE PRESENTATION: A male patient in his fifties underwent SILE for insulinomas. To prevent injury to the MPD, an NPS was preoperatively placed. All surgical procedures were performed through a single mini-laparotomy site in the umbilicus. NPS placement facilitated identification of the MPD under laparoscopic ultrasonography. Enucleation was successfully completed without any injury to the MPD, and the NPS was removed immediately after confirming that there was no injury to the MPD by the NPS via pancreatography. The postoperative course was uneventful. CLINICAL DISCUSSION: This report serves to highlight the maximum safety and minimal invasiveness of SILE with the preoperative NPS placement. Preoperative NPS placement is useful for avoiding injury to the MPD during enucleation and has the merit of helping to recognize whether leakage occurs by intraoperative pancreatography via the NPS. CONCLUSION: Preoperative NPS placement helps to ensure the safe enucleation of pancreatic insulinomas even in single-incision laparoscopic surgery, with minimal invasiveness and better cosmetic outcomes.

Tumor-to-tumor metastasis: an extremely rare combination with renal cell carcinoma as the donor and a pancreatic neuroendocrine tumor as the recipient.

BACKGROUND: Tumor-to-tumor metastasis is a rare phenomenon in which primary tumor cells metastasize hematogenously into another tumor. Herein, we report an extremely rare case of a renal cell carcinoma metastasis into a pancreatic neuroendocrine tumor exhibiting a tumor-to-tumor metastasis. Ours is the third reported case worldwide. CASE PRESENTATION: The patient, a 72-year-old male, was referred to our hospital for further examination and treatment due to high levels of prostate-specific antigen. A left renal tumor and pancreatic head tumor were revealed incidentally on screening computed tomography. There were suspected to be a renal cell carcinoma and primary pancreatic neuroendocrine tumor or pancreatic metastasis from the renal cell carcinoma according to preoperative examination. The left nephrectomy and subtotal stomach-preserving pancreaticoduodenectomy were performed because of the pancreatic tumor indicated for operation in either case of diagnosis. Postoperative pathological examination showed a diagnosis of clear cell renal cell carcinoma for the left renal tumor. The pancreatic tumor was diagnosed with clear cell renal cell carcinoma metastasis into the pancreatic neuroendocrine tumor, that is to say tumor-to-tumor metastasis. CONCLUSION: In some cases, conservative approach is selected for pancreatic neuroendocrine tumor patients who meet some requirements. However, if such patients exhibit tumor-to-tumor metastasis which combines with renal cell carcinoma and pancreatic neuroendocrine tumor as this case, conservative approach leads to progression of renal cell carcinoma. Therefore, conceiving the possibility of tumor-to-tumor metastasis, it is necessary to carefully choose a treatment plan for pancreatic neuroendocrine tumor patients associated with renal cell carcinoma, not easily choosing conservative approach.

The oligodendroglial histological features are not independently predictive of patient prognosis in lower-grade gliomas.

The relevance of oligodendroglial histological features to patient prognoses is controversial. 93 LrGGs resected for about 2 decades were re-assessed based on WHO2007 with special interest to pure oligodendroglial diagnosis (oligodendroglioma or anaplastic oligodendroglioma) and presence of CFO features. Those histological features, patients OS, and tumor chromosomal/genetic characteristics were correlated each other in each of the 3 IDH-1p/19q-based molecular groups. There was significant association between 1p19q status with the oligodendroglial histological diagnosis as well as presence of CFO in the entire cohort. The oligodendroglial diagnosis was associated with longer OS in IDHmut/codel group; however, this association was not significant in the multivariate analyses. In IDHmut/noncodel and IDH-wildtype groups, the oligodendroglial diagnosis was not associated with patient OS. Presence of CFO was not associated with patient OS in any molecular groups. Gain of 8q was associated with the oligodendroglial diagnosis in IDHmut/noncodel group. Neither the oligodendroglial diagnosis nor CFO was predictive for the methylation status of the MGMT gene in any molecular groups. The oligodendroglial histological features are not independently predictive of either patient prognosis or chemotherapeutic response in LrGGs, leaving the possibility of marginal favorable association only in IDHmut/codel tumors.

[A case of advanced mullerian cancer successfully treated with S-1 chemotherapy].

A 79-year-old woman was referred to our hospital with complaints of dyspnea. She was diagnosed with massive pleural effusion and cytology demonstrated the presence of adenocarcinoma, but no solid tumors were found in the systemic examination. Her serum CYFRA and CA125 level were increased. She was diagnosed with an effusion type of lung cancer or a cancer of unknown origin. S-1/CDDP was the chemotherapy of choice. After 2 courses of the treatment, her serum CYFRA level and CA125 level were normalized, and a chest CT detected no pleural effusion. Two years and 3 months after the first treatment, her CA125 level was increased. We found an FDG accumulation in her pelvic lesion by PET examination. To identify the FDG accumulated lesion in her pelvis, an operation was performed. Histopathological examination of the right ovary demonstrated the presence of an adenocarcinoma. Postoperatively, we administered 2 courses of paclitaxel/carboplatin combination treatment, considering the right ovarian tumor was the primary lesion. The patient remained alive and in good condition without any signs of recurrence 2 years after second treatment. This case suggests that S-1 therapy may be effective for patients with mullerian cancer.

Double Meningioma: A Case of Two Fibrous Meningiomas Coexisting Isolatedly in Meningothelial Meningioma.

Meningiomas are the most common intracranial primary neoplasm in adults, and show various histological subtypes, indicating heterogeneous clinical and molecular genetic characteristics. Different subtypes of meningioma coexisting independently within the main tumor of another different subtype is a quite rare clinical situation. A 69-year-old woman presented with a several- year history of dizziness as a non-specific complaint. Magnetic resonance imaging (MRI) revealed an extra-axial mass lesion in the left parieto-occipital region including two well-demarcated, round mass components. Total resection was performed via left parieto-occipital craniotomy. Two white masses were identified within the main tumor, with neither showing dural attachments. Pathological findings showed the main mass represented meningothelial meningioma and the demarcated mass lesions were both fibrous meningiomas. No transitional features existed between these subtypes. No differences in genetic characteristics were evident between subtypes of meningioma. We have described, apparently for the first time, a case of two fibrous meningiomas coexisting in an isolated manner in meningothelial meningioma with the similar molecular genetic profile.

Recurrence of cervical intramedullary gliofibroma.

INTRODUCTION: Gliofibroma is a rare tumor that develops in the brain and spinal cord. Due to the rarity of its nature, its pathophysiology and appropriate treatment remain elusive. We report a case of intramedullary spinal cord gliofibroma that was surgically treated multiple times. This report is of great significance because this is the first case of recurrence of this tumor. CASE PRESENTATION: A 32-year-old woman complained of gait disturbance and was referred to our institution. At the age of 13 years, she was diagnosed with intramedullary gliofibroma and underwent gross total resection (GTR) in another hospital. Based on imaging findings, tumor recurrence was suspected at the level of cervical spinal cord, and surgery was performed. However, the resection volume was limited to 50% because the boundary between the tumor and spinal cord tissue was unclear and intraoperative neuromonitoring alerted paralysis. At 1 year postoperatively, the second surgery was performed to try to resect the residual tumor, but subtotal resection was achieved at most. At 2 years after the final surgery, no tumor recurrence was observed, and neurologic function was maintained to gait with cane. DISCUSSION: Although complete resection is desirable for this rare tumor at the initial surgery, there is a possibility to recur even after GTR with long-term follow-up. During surgical treatment for tumor recurrence, fair adhesion to the spinal cord is expected, and reoperation and/or adjuvant therapy might be considered in the future if the tumor regrows and triggers neurological deterioration.

A case with massive hemobilia long-term after internal drainage surgery for congenital biliary dilation.

BACKGROUND: Currently, there is an unwavering consensus that the standard surgery for congenital biliary dilation (CBD) is extrahepatic bile duct resection and choledochojejunostomy. However, decades prior, choledochocyst-gastrointestinal anastomosis without extrahepatic bile duct resection (internal drainage surgery, IDS) was preferred for CBD because of its simplicity. Currently, there is almost no chance of a surgeon encountering a patient who has undergone old-fashioned IDS, which has been completely obsolete due to the risk of carcinogenesis from the remaining bile duct. Moreover, the pathological condition long after IDS is unclear. Herein, we report a case of life-threatening bile duct bleeding as well as carcinoma of the bile duct 62 years after IDS in a patient with CBD. CASE PRESENTATION: An 82-year-old Japanese woman with hemorrhagic shock due to gastrointestinal bleeding was transferred to our hospital. She had a medical history of unspecified surgery for CBD at the age of 20. Based on imaging findings and an understanding of the historical transition of the surgical procedure for CBD, the cause of gastrointestinal bleeding was determined to be rupture of the pseudoaneurysm of the dilated bile duct that remained after IDS. Hemostasis was successfully performed by transcatheter arterial embolization (TAE) in an emergency setting. Then, elective surgery for extrahepatic bile duct resection and choledochojejunostomy was performed to prevent rebleeding. Pathological examination revealed severely and chronically inflamed mucosa of the bile duct. Additionally, cholangiocarcinoma (Tis, N0, M0, pStage 0) was incidentally revealed. CONCLUSION: It has been indicated that not only carcinogenesis, but also a risk of life-threatening bleeding exists due to long-lasting chronic inflammation to the remnant bile duct after IDS for CBD. Additionally, both knowledge of which CBD operation was performed, and an accurate clinical history are important for the diagnosis of hemobilia.

Endocrinological and MRI features of pituitary adenomas with marked xanthogranulomatous reaction.

INTRODUCTION: The study aims to describe the endocrinological and magnetic resonance imaging (MRI) features of the rarely reported xanthogranulomas associated with pituitary adenoma. METHODS: Of 231 consecutive pituitary adenomas treated surgically, those with xanthogranulomatous reaction on histology were reviewed. RESULTS: Five patients (2.2%) had an adenoma with marked xanthogranulomatous reaction. They were all nonfunctioning macroadenomas and presented with anterior pituitary insufficiencies. On MRI, all adenomas showed mixed signal intensities on T1- and T2-weighted images with heterogeneous gadolinium enhancement, reflecting their complex histological features: Cholesterol clefts typically showed T1 high- and T2 low-signal intensities. Preoperative diagnosis was difficult in a case predominantly featuring xanthogranuloma. Although none of them had episodes of pituitary apoplexy, hemosiderin deposits and cysts with xanthochromic-like fluid were observed in five and four cases, respectively. CONCLUSIONS: Xanthogranulomatous reaction may develop in macroadenomas, probably triggered by hemorrhagic processes despite no apoplectic episodes. They typically exhibit complex mixed signal intensity on MRI, particularly T1 high- and T2 low-signal intensities, and patients present with pituitary dysfunction.

TERT promoter mutation confers favorable prognosis regardless of 1p/19q status in adult diffuse gliomas with IDH1/2 mutations.

TERT promoter mutations are commonly associated with 1p/19q codeletion in IDH-mutated gliomas. However, whether these mutations have an impact on patient survival independent of 1p/19q codeletion is unknown. In this study, we investigated the impact of TERT promoter mutations on survival in IDH-mutated glioma cases. Detailed clinical information and molecular status data were collected for a cohort of 560 adult patients with IDH-mutated gliomas. Among these patients, 279 had both TERT promoter mutation and 1p/19q codeletion, while 30 had either TERT promoter mutation (n = 24) or 1p/19q codeletion (n = 6) alone. A univariable Cox proportional hazard analysis for survival using clinical and genetic factors indicated that a Karnofsky performance status score (KPS) of 90 or 100, WHO grade II or III, TERT promoter mutation, 1p/19q codeletion, radiation therapy, and extent of resection (90-100%) were associated with favorable prognosis (p < 0.05). A multivariable Cox regression model revealed that TERT promoter mutation had a significantly favorable prognostic impact (hazard ratio = 0.421, p = 0.049), while 1p/19q codeletion did not have a significant impact (hazard ratio = 0.648, p = 0.349). Analyses incorporating patient clinical and genetic information were further conducted to identify subgroups showing the favorable prognostic impact of TERT promoter mutation. Among the grade II-III glioma patients with a KPS score of 90 or 100, those with IDH-TERT co-mutation and intact 1p/19q (n = 17) showed significantly longer survival than those with IDH mutation, wild-type TERT, and intact 1p/19q (n = 185) (5-year overall survival, 94% and 77%, respectively; p = 0.032). Our results demonstrate that TERT promoter mutation predicts favorable prognosis independent of 1p/19q codeletion in IDH-mutated gliomas. Combined with its adverse effect on survival among IDH-wild glioma cases, the bivalent prognostic impact of TERT promoter mutation may help further refine the molecular diagnosis and prognostication of diffuse gliomas.