Paradoxical Worsening of Cerebral Venous Sinus Thrombosis Due to Heparin-Induced Thrombocytopenia: A Case Report and Literature Review.

Development of cerebral venous sinus thrombosis (CVST) is a rare manifestation of heparin-induced thrombocytopenia (HIT). Herein, we present a case in which heparin administration for primary CVST caused paradoxical worsening of CVST secondary to HIT. A 53-year-old woman diagnosed with CVST was provided with intravenous unfractionated heparin therapy. After 12 days, the patient presented tonic convulsive seizures (TCS). Subsequent magnetic resonance image (MRI) scans revealed an exacerbation of cerebral edema with a subcortical hemorrhage on the left parietal lobe. Laboratory test results revealed a significant decline in platelet count. Heparin was immediately discontinued and replaced with argatroban. The definitive diagnosis of HIT was made through the presence of HIT antibodies. The present case, in which HIT caused the secondary CVST exacerbation, is distinctly rare. Our case provides an instructive example by highlighting the potential of TCS as the first sign of HIT development during CVST treatment.

Technique for Recanalization of Sheath Introducer Occlusion due to Captured Thrombus during Mechanical Thrombectomy for Acute Ischemic Stroke: A Technical Note.

Objective: Mechanical thrombectomy (MT) is the gold standard treatment for acute ischemic stroke. During these interventions, a thrombus frequently obstructs a guiding catheter. The obstructed guiding catheter should be withdrawn before distal embolism occurs; however, albeit infrequently, the thrombus occludes even a sheath introducer (SI). While conventionally new SI placement is required for continuation of treatment, we propose a viable alternative for recanalization of the occluded SI, termed vacuum-assisted delivery of thrombus (VADT), with a clinical report of our cases. The usefulness of this technique was also evaluated in simulation experiments. Case Presentations: The VADT procedure is as follows: 1) insert a peel-away sheath, originally attached to a balloon-guiding catheter (BGC), into the SI to continuously open the hemostatic valve; 2) advance the BGC into the peel-away sheath while applying mechanical aspiration; and 3) remove the peel-away sheath/BGC assembly slowly. In a simulation environment using an artificial thrombus, we repeated the VADT procedure five times and reproducibly achieved SI reopening within only 10-20 seconds. From March 2013 to September 2022, 204 patients were treated with MT at our stroke center and SI occlusion occurred in three patients (1.5%). These events occurred exclusively in patients with extracranial internal carotid artery occlusion. All three patients with SI occlusion underwent successfully thrombus extraction in the SI using the VADT on the first try. Conclusion: The results of clinical experience and simulation experiments strongly support VADT as a reliable option for recanalization of an occluded SI.

Correlation of T1- to T2-weighted signal intensity ratio with T1- and T2-relaxation time and IDH mutation status in glioma.

The current study aimed to test whether the ratio of T1-weighted to T2-weighted signal intensity (T1W/T2W ratio: rT1/T2) derived from conventional MRI could act as a surrogate relaxation time predictive of IDH mutation status in histologically lower-grade gliomas. Strong exponential correlations were found between rT1/T2 and each of T1- and T2-relaxation times in eight subjects (rT1/T2 = 1.63exp-0.0005T1-relax + 0.30 and rT1/T2 = 1.27exp-0.0081T2-relax + 0.48; R2 = 0.64 and 0.59, respectively). In a test cohort of 25 patients, mean rT1/T2 (mrT1/T2) was significantly higher in IDHwt tumors than in IDHmt tumors (p < 0.05) and the optimal cut-off of mrT1/T2 for discriminating IDHmt was 0.666-0.677, (AUC = 0.75, p < 0.05), which was validated in an external domestic cohort of 29 patients (AUC = 0.75, p = 0.02). However, this result was not validated in an external international cohort derived from TCIA/TCGA (AUC = 0.63, p = 0.08). The t-Distributed Stochastic Neighbor Embedding analysis revealed a greater diversity in image characteristics within the TCIA/TCGA cohort than in the two domestic cohorts. The failure of external validation in the TCIA/TCGA cohort could be attributed to its wider variety of original imaging characteristics.

Revisiting the definition of glioma recurrence based on a phylogenetic investigation of primary and re-emerging tumor samples: a case report.

A recurrent tumor is defined as a re-emerging subclone originating from an ancestorial clone of the primary neoplasm. Hence, it should be distinguished from de novo tumor emerging from other clones. Herein, we describe an exceptional case in which the locally re-emerging glioma did not share genetic alterations of the primary tumor. While the initial tumor harbored mutations in IDH1 and TERT genes as well as 1p/19q codeletion, the re-emerging tumor did not present any of these genetic abnormalities. Variant calling for tumor samples using whole-genome sequencing revealed that 1696 mutations within the primary tumor faded in the re-emerging tumor, and that 4591 mutations were newly detected in the re-emerging tumor. These results suggested that the initial and re-emerging tumors did not share same clonal origins, although the second tumor appeared adjacent to the old surgical cavity 5 years after the initial surgery. We finally speculated that the re-emerging tumor could be a "de novo glioma" or "radiation-induced glioblastoma following treatment of a diffuse glioma." This case highlights the importance of molecular re-evaluation of clinically diagnosed "recurrent" glioma lesions.

Dysbiosis of Gut Microbiome Is Associated With Rupture of Cerebral Aneurysms.

BACKGROUND AND PURPOSE: Environmental factors are important with respect to the rupture of cerebral aneurysms. However, the relationship between the gut microbiome, an environmental factor, and aneurysm rupture is unclear. Therefore, we compared the gut microbiome in patients with unruptured intracranial aneurysms (UIAs) and ruptured aneurysms (RAs) to identify the specific bacteria causing the rupture of cerebral aneurysms. METHODS: A multicenter, prospective case-control study was conducted over one year from 2019 to 2020. The fecal samples of patients with stable UIAs and RAs immediately after onset were collected. Their gut microbiomes were analyzed using 16S rRNA sequencing. Subsequently, a phylogenetic tree was constructed, and polymerase chain reaction was performed to identify the specific species. RESULTS: A total of 28 RAs and 33 UIAs were included in this study. There was no difference in patient characteristics between RAs and UIAs: age, sex, hypertension, dyslipidemia, diabetes status, body mass index, and smoking. No difference was observed in alpha diversity; however, beta diversity was significantly different in the unweighted UniFrac distances. At the phylum level, the relative abundance of Campylobacter in the RA group was larger than that in the UIA group. Furthermore, the gut microbiome in the RA and UIA groups exhibited significantly different taxonomies. However, Campylobacter was focused on because it is widely known as pathogenic among these bacteria. Then, a phylogenetic tree of operational taxonomic units related to Campylobacter was constructed and 4 species were identified. Polymerase chain reaction for these species identified that the abundance of the genus Campylobacter and Campylobacter ureolyticus was significantly higher in the RA group. CONCLUSIONS: The gut microbiome profile of patients with stable UIAs and RAs were significantly different. The genus Campylobacter and Campylobacter ureolyticus may be associated with the rupture of cerebral aneurysms.

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.

Clinical significance of CDKN2A homozygous deletion in combination with methylated MGMT status for IDH-wildtype glioblastoma.

OBJECTIVE: Accumulating evidence from recent molecular diagnostic studies has indicated the prognostic significance of various genetic markers for patients with glioblastoma (GBM). To evaluate the impact of such genetic markers on prognosis, we retrospectively analyzed the outcomes of patients with IDH-wildtype GBM in our institution. In addition, to assess the impact of bevacizumab (BEV) treatment, we compared overall survival (OS) between the pre- and post-BEV eras. METHODS: We analyzed the data of 100 adult patients (over 18 years old) with IDH-wildtype GBM from our database between February 2006 and October 2018. Genetic markers, such as MGMT methylation status, EGFR amplification, CDKN2A homozygous deletion, and clinical factors were analyzed by evaluating the patients' OS. RESULTS: CDKN2A homozygous deletion showed no significant impact on OS in patients with methylated MGMT status (p = 0.5268), whereas among patients with unmethylated MGMT status, there was a significant difference in OS between patients with and without CDKN2A homozygous deletion (median OS: 14.7 and 16.9 months, respectively, p = 0.0129). This difference was more evident in the pre-BEV era (median OS: 10.1 and 15.6 months, respectively, p = 0.0351) but has become nonsignificant in the post-BEV era (median OS: 16.0 and 16.9 months, respectively, p = 0.1010) due to OS improvement in patients with CDKN2A homozygous deletion. However, these findings could not be validated in The Cancer Genome Atlas cohort. CONCLUSIONS: MGMT and CDKN2A status subdivided our cohort into three race-specific groups with different prognoses. Our findings indicate that BEV approval in Japan led to OS improvement exclusively for patients with concurrent unmethylated MGMT status and CDKN2A homozygous deletion.

Anatomical variation of the internal carotid artery and its implication to the endoscopic endonasal translacerum approach.

BACKGROUND: The endoscopic endonasal trans-lacerum approach (EETLA) is useful in handling skull base tumors around inferior petrous apex (IPA); however, its surgical corridor is exclusively a triangular space (supra-eustachian triangle [SET]), between the internal carotid artery (ICA) and eustachian tube. METHODS: We investigated correlation between SET size and extent of resection around the IPA (lateral extent of resection [EOR]) through a retrospective analysis of 15 surgeries using EETLA. RESULTS: Of 15 cases (9 chordomas, 4 chondrosarcomas, and 2 meningiomas), 20 sides of IPA were affected by the tumor. When being restricted to sides with severe lateral tumor extension beyond the midpoint of petrous ICA (10 sides), the SET size was significantly broader in the group with lateral EOR of ≥90% (p value = 0.019). CONCLUSIONS: The SET size was a powerful index of tumor resectability in EETLA, especially in cases with severe tumor extension. The individual anatomical variations should be considered when determining EETLA application.

Efficacy of the Endoscopic Triportal Transmaxillary Approach for Treating Lateral Middle Skull Base Tumors: A Technical Note and Retrospective Case Series.

BACKGROUND: The endoscopic approach, chiefly via the maxillary sinus, has growing applications for the lateral skull base, and can be classified into the use of "endonasal" or "sublabial" entry. Although the endonasal transmaxillary approach has been well accepted, it has a limitation with respect to the lateral exposure. A possible solution is the use of the sublabial transmaxillary approach via the canine fossa, which assures lateral accessibility. In clinical practice, we have taken advantage of the concomitant use of the endonasal and sublabial transmaxillary approach for selected patients harboring lateral skull base lesions. In addition to binostril pathways, canine fossa trephination was constructed to facilitate this combined approach, termed the endoscopic triportal transmaxillary approach (ETTA). METHODS: The efficacy of the ETTA was evaluated within a case series. A single-institution retrospective analysis was performed in patients with lateral middle skull base tumors treated via ETTA. RESULTS: In clinical practice, 4 patients were eligible for the study, including 1 receiving a combined endoscopic and transcranial approach. No major complications occurred in patients included in this series. The ETTA facilitated the dynamic manipulation of instruments, which led to rapid hemostasis and the satisfactory surgical resection of tumors. Furthermore, it reduced intraoperative postural stress experienced by the surgeons who performed the procedures. CONCLUSIONS: The concomitant use of the trans-canine fossa approach effectively ameliorated significant technical challenges that tend to occur when using a purely endonasal approach. The ETTA can be an attractive option for treating lateral and middle skull base lesions.

Molecular characteristics and clinical outcomes of elderly patients with IDH-wildtype glioblastomas: comparative study of older and younger cases in Kansai Network cohort.

Aging is a known negative prognostic factor in glioblastomas (GBM). Whether particular genetic backgrounds are a factor in poor outcomes of elderly patients with GBM warrants investigation. We aim to elucidate any differences between older and younger adult patients with IDH-wildtype GBM regarding both molecular characteristics and clinical outcomes. We collected adult cases diagnosed with IDH-wildtype GBM from the Kansai Network. Clinical and pathological characteristics were analyzed retrospectively and compared between older (≥ 70 years) and younger (≤ 50 years) cases. Included were 92 older vs. 33 younger cases. The older group included more patients with preoperative Karnofsky performance status score < 70 and had a shorter survival time than the younger group. MGMT promoter was methylated more frequently in the older group. TERT promoter mutation was more common in the older group. There were significant differences in DNA copy-number alteration profiles between age groups in PTEN deletion and CDK4 amplification/gain. In the older group, no molecular markers were identified, but surgical resection was an independent prognostic factor. Age-specific survival difference was significant in the MGMT methylated and TERT wildtype subgroup. Elderly patients have several potential factors in poor prognosis of glioblastomas. Varying molecular profiles may explain differing rates of survival between generations.

Submucosal Inferior Turbinectomy to Widen the Surgical Corridor for Endoscopic Endonasal Skull Base Surgery.

The nasal cavity is the exclusive surgical corridor for endoscopic endonasal surgery; however, it is sometimes too narrow to allow extensive surgical maneuvering. Here we show the technique of submucosal inferior turbinectomy (SIT) to widen this surgical corridor. Its effectiveness is evaluated quantitatively by comparing pre- and intraoperative magnetic resonance images. Between March 2015 and October 2018, we performed endoscopic endonasal resection of 57 skull base tumors with 3T intraoperative magnetic resonance imaging (iMRI). Among these resections, cases with previous endonasal surgery and cases for which the iMRI did not cover the entire nasal cavity were excluded. Finally, six cases with and 19 cases without SIT were included in the subsequent retrospective analysis. We measured the dimensions of the narrowest area in inferior nasal cavity on pre- and intraoperative coronal plane gadolinium (Gd)-enhanced T1-weighted MR images using dedicated software, and compared them. The incidence rates of postoperative nasal complaints at outpatient clinics were also compared. Considerable widening of the inferior nasal cavity could be achieved with the SIT, which was statistically significant compared with those without the SIT (111.1 ± 56.5% vs. 39.4 ± 59.4%, respectively; P = 0.0093). In terms of the incidence rate of postoperative nasal complaints at 6 months, there was no statistical difference between the groups (33.3% vs. 15.8%, respectively; P = 0.35). SIT is effective for widening the surgical corridor while keeping nasal function and is especially helpful for lower clivus and laterally extended skull base lesions.

Comparative Evaluation of 3-Dimensional High Definition and 2-Dimensional 4-K Ultra-High Definition Endoscopy Systems in Endonasal Skull Base Surgery.

BACKGROUND: The differences between 3-dimensional (3D) high definition (HD) and 2-dimensional (2D) 4-K ultra-HD (4K) endoscopy and their respective advantages remain unclear. OBJECTIVE: To evaluate the utility of these endoscopy systems in endonasal skull base surgery. METHODS: Consecutive series of endoscopic endonasal surgeries performed after introduction of 3D/HD and 2D/4K systems (July 2017) were retrospectively evaluated. Sporadic cases treated with either system, or a conventional 2D standard definition (SD) system, during the rental period from March 2016 were also included. Objective comparisons between the systems were made for newly diagnosed Knosp grade 0 to 3 pituitary adenomas. Surgical procedures were divided into nasal, sphenoidal, and intradural phases, and the surgical procedural time was compared for each phase. The time required for and accuracy of suturing the sellar floor dura was also evaluated. RESULTS: A total of 74 cases were treated with 3D/HD and/or 2D/4K, and 12 cases with 2D/SD. 3D/HD was advantageous in the nasal phase because of its intuitive depth perception. 2D/4K was advantageous in the intradural phase because of its superior image quality. Surgical time of the nasal phase with 3D/HD, and that of the intradural phase with 2D/4K, were significantly shorter than that with 2D/SD. The time required for and accuracy of sellar floor dural suturing showed a trend toward improving in the order of 2D/SD, 2D/4K, and 3D/HD. CONCLUSION: 3D/HD and 2D/4K endoscopy systems have different advantages, which are useful in distinct surgical phases. Understanding the characteristics of endoscopy systems is important for selecting the most appropriate system for distinct surgical situations.

Distribution differences in prognostic copy number alteration profiles in IDH-wild-type glioblastoma cause survival discrepancies across cohorts.

The diagnosis and prognostication of glioblastoma (GBM) remain to be solely dependent on histopathological findings and few molecular markers, despite the clinical heterogeneity in this entity. To address this issue, we investigated the prognostic impact of copy number alterations (CNAs) using two population-based IDH-wild-type GBM cohorts: an original Japanese cohort and a dataset from The Cancer Genome Atlas (TCGA). The molecular disproportions between these cohorts were dissected in light of cohort differences in GBM. The Japanese cohort was collected from cases registered in Kansai Molecular Diagnosis Network for CNS tumors (KNBTG). The somatic landscape around CNAs was analyzed for 212 KNBTG cases and 359 TCGA cases. Next, the clinical impacts of CNA profiles were investigated for 140 KNBTG cases and 152 TCGA cases treated by standard adjuvant therapy using temozolomide-based chemoradiation. The comparative profiling indicated unequal distribution of specific CNAs such as EGFR, CDKN2A, and PTEN among the two cohorts. Especially, the triple overlap CNAs in these loci (triple CNA) were much higher in frequency in TCGA (70.5%) than KNBTG (24.3%), and its prognostic impact was independently validated in both cohorts. The KNBTG cohort significantly showed better prognosis than the TCGA cohort (median overall survival 19.3 vs 15.6 months). This survival difference between the two cohorts completely resolved after subclassifying all cases according to the triple CNA status. The prognostic significance of triple CNA was identified in IDH-wild-type GBM. Distribution difference in prognostic CNA profiles potentially could cause survival differences across cohorts in clinical studies.

11C-methionine-18F-FDG dual-PET-tracer-based target delineation of malignant glioma: evaluation of its geometrical and clinical features for planning radiation therapy.

OBJECTIVE: It is important to correctly and precisely define the target volume for radiotherapy (RT) of malignant glioma. 11C-methionine (MET) positron emission tomography (PET) holds promise for detecting areas of glioma cell infiltration: the authors' previous research showed that the magnitude of disruption of MET and 18F-fluorodeoxyglucose (FDG) uptake correlation (decoupling score [DS]) precisely reflects glioma cell invasion. The purpose of the present study was to analyze volumetric and geometrical properties of RT target delineation based on DS and compare them with those based on MRI. METHODS: Twenty-five patients with a diagnosis of malignant glioma were included in this study. Three target volumes were compared: 1) contrast-enhancing core lesions identified by contrast-enhanced T1-weighted images (T1Gd), 2) high-intensity lesions on T2-weighted images, and 3) lesions showing high DS (DS ≥ 3; hDS). The geometrical differences of these target volumes were assessed by calculating the probabilities of overlap and one encompassing the other. The correlation of geometrical features of RT planning and recurrence patterns was further analyzed. RESULTS: The analysis revealed that T1Gd with a 2.0-cm margin was able to cover the entire high DS area only in 6 (24%) patients, which indicates that microscopic invasion of glioma cells often extended more than 2.0 cm beyond a Gd-enhanced core lesion. Insufficient coverage of high DS regions with RT target volumes was suggested to be a risk for out-of-field recurrence. Higher coverage of hDS by T1Gd with a 2-cm margin (i.e., higher values of "[T1Gd + 2 cm]/hDS") had a trend to positively impact overall and progression-free survival. Cox regression analysis demonstrated that low coverage of hDS by T1Gd with a 2-cm margin was predictive of disease recurrence outside the Gd-enhanced core lesion, indicative of out-of-field reoccurrence. CONCLUSIONS: The findings of this study indicate that MRI is inadequate for target delineation for RT in malignant glioma treatment. Expanding the treated margins substantially beyond the MRI-based target volume may reduce the risk of undertreatment, but it may also result in unnecessary irradiation of uninvolved regions. As MET/FDG PET-DS seems to provide more accurate information for target delineation than MRI in malignant glioma treatment, this method should be further evaluated on a larger scale.

Life-Threatening Hemorrhagic Moyamoya Disease: Report of Rare Case of Atraumatic Acute Subdural Hematoma Due to Ruptured Transdural Anastomosis.

BACKGROUND: Atraumatic acute subdural hematoma (ASDH) associated with moyamoya disease (MMD) is rare, and only a few studies have reported the bleeding origin. We present a case of atraumatic ASDH attributable to a transdural anastomosis that developed owing to the compensatory mechanisms involved in the pathogenesis of advanced MMD. This is the first case of life-threatening atraumatic ASDH associated with MMD in which the rupture point was clearly visualized using a 3-dimensional rotational reconstructed image. CASE DESCRIPTION: A 37-year-old woman presented with sudden-onset, serious, atraumatic ASDH requiring emergency decompressive craniectomy. The cerebral angiograms revealed that she had advanced MMD with transdural anastomosis that was classified as Suzuki stage V with a 5-mm saccular aneurysm in the middle meningeal artery on the affected side, which was suggested as the bleeding origin. Follow-up angiograms demonstrated that the aneurysm spontaneously disappeared and was inferred to be a pseudoaneurysm. We performed a left extraintracranial bypass to prevent recurrent hemorrhage. With intensive rehabilitation, the patient accordingly achieved stroke-free survival with a modified Rankin Scale score of 3 for 1 year. CONCLUSIONS: Atraumatic ASDH associated with MMD is a rare type of hemorrhagic MMD, and a 3-dimensional-rotational reconstructed image was useful to confirm the origin of the bleeding. The transdural anastomosis development most likely correlates with the occurrence of any type of hemorrhagic MMD. We should consider that the transdural anastomosis collapse can cause a life-threatening atraumatic ASDH and should plan a surgical strategy carefully so as not to destroy collateral supply through the transdural anastomosis in such cases.

A case of pilocytic astrocytoma requiring tumor resection during pregnancy.

Low-grade glioma (LGG) is often encountered in relatively young individuals, including women of childbearing age. Notably, case series describing pregnant women with LGG have been reported in the literature. The present study reported a case of pilocytic astrocytoma (PA) requiring tumor resection during pregnancy. The patient had a history of γ-knife radiotherapy for a brainstem tumor 17 years previously. The histological diagnosis was unclear. The tumor had remained stable following radiosurgery for 17 years, including during her first pregnancy. However, rapid tumor growth around the fourth ventricle occurred at week 25 of her second pregnancy. Therefore, an urgent tumor resection was performed despite the pregnancy. Partial resection was performed since the tumor had infiltrated the brainstem. The histological diagnosis was PA. The residual tumor volume decreased gradually following the delivery. Immunostaining of the tumor for the expression of progesterone receptor revealed focal staining. It is possible that reproductive factors, including specific hormonal changes during pregnancy, affected the tumor growth. The present study described this rare case of PA, which exhibited rapid growth and required urgent surgery during pregnancy.

Efficacy of generic allometric equations for estimating biomass: a test in Japanese natural forests.

Accurate estimation of tree and forest biomass is key to evaluating forest ecosystem functions and the global carbon cycle. Allometric equations that estimate tree biomass from a set of predictors, such as stem diameter and tree height, are commonly used. Most allometric equations are site specific, usually developed from a small number of trees harvested in a small area, and are either species specific or ignore interspecific differences in allometry. Due to lack of site-specific allometries, local equations are often applied to sites for which they were not originally developed (foreign sites), sometimes leading to large errors in biomass estimates. In this study, we developed generic allometric equations for aboveground biomass and component (stem, branch, leaf, and root) biomass using large, compiled data sets of 1203 harvested trees belonging to 102 species (60 deciduous angiosperm, 32 evergreen angiosperm, and 10 evergreen gymnosperm species) from 70 boreal, temperate, and subtropical natural forests in Japan. The best generic equations provided better biomass estimates than did local equations that were applied to foreign sites. The best generic equations included explanatory variables that represent interspecific differences in allometry in addition to stem diameter, reducing error by 4-12% compared to the generic equations that did not include the interspecific difference. Different explanatory variables were selected for different components. For aboveground and stem biomass, the best generic equations had species-specific wood specific gravity as an explanatory variable. For branch, leaf, and root biomass, the best equations had functional types (deciduous angiosperm, evergreen angiosperm, and evergreen gymnosperm) instead of functional traits (wood specific gravity or leaf mass per area), suggesting importance of other traits in addition to these traits, such as canopy and root architecture. Inclusion of tree height in addition to stem diameter improved the performance of the generic equation only for stem biomass and had no apparent effect on aboveground, branch, leaf, and root biomass at the site level. The development of a generic allometric equation taking account of interspecific differences is an effective approach for accurately estimating aboveground and component biomass in boreal, temperate, and subtropical natural forests.

Choroid Plexus Metastasis of Follicular Thyroid Carcinoma Diagnosed due to Intraventricular Hemorrhage.

Choroid plexus metastasis (CPM) is extremely rare and originates most frequently from renal cell carcinoma (RCC). We herein report the case of a 58-year-old man who developed a solitary CPM lesion derived from follicular thyroid carcinoma in addition to intraventricular hemorrhage. Computed tomography revealed acute hydrocephalus as a result of the hemorrhage, and we planned endoscopic hematoma evacuation. Since it was too difficult to reach the hematoma, we considered the possibility of a neoplasm and performed a biopsy of the lesion, the results of which led to an accurate diagnosis of CPM in this case. We also review previous reports of CPM originating from thyroid carcinoma compared with RCC.

Efficacy of temozolomide and bevacizumab for the treatment of leptomeningeal dissemination of recurrent glioblastoma: A case report.

The prognosis of leptomeningeal dissemination of recurrent glioblastoma is poor, and chemotherapy results in minimal palliative efficacy. Temozolomide (TMZ) is an established therapy for patients with malignant glioma and the standard of care in parenchymal gliomas; however, few reports have been published with regard to its use for the treatment of leptomeningeal dissemination. Only one report has indicated the radiographic response of leptomeningeal dissemination to a TMZ rechallenge, suggesting a potential causative effect. While bevacizumab is an effective therapy for recurrent glioblastoma, its effect on leptomeningeal dissemination of recurrent glioblastoma remains unclear. The present study reports a case of leptomeningeal dissemination of recurrent glioblastoma in which transient neurological and radiological improvement was observed following chemotherapy with TMZ and bevacizumab. However, five months after the diagnosis of leptomeningeal dissemination the patient succumbed to the disease.