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Dive into the research topics where Hajime Yonezawa is active.

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Featured researches published by Hajime Yonezawa.


Brain Tumor Pathology | 2014

Immunoreactivity of Wnt5a, Fzd2, Fzd6, and Ryk in glioblastoma: evaluative methodology for DAB chromogenic immunostaining

Hirofumi Hirano; Hajime Yonezawa; Shunji Yunoue; Mika Habu; Hiroyuki Uchida; Takako Yoshioka; Shosei Kishida; Michiko Kishida; Tatsuki Oyoshi; Shingo Fujio; Sei Sugata; Hitoshi Yamahata; Ryousuke Hanaya; Kazunori Arita

The aim of this study was to determine the influence of Wnt5a and its receptors on the survival of glioblastoma patients and to determine reliable evaluation methods for immunohistochemistry. Diagnostic specimens from 41 histopathologically confirmed primary glioblastoma patients whose Gd-enhanced tumors had been totally removed were immunohistochemically stained for Wnt5a, Fzd2, Fzd6, and Ryk. The immunoreactivity was evaluated using the following methods: (A) grayscale optical density after color deconvolution, (B) percentage of stained cells, (C) density of stained cells, (D) staining amount (multiplication product of B and C), and (E) staining rank. The data sets of A to E were statistically evaluated by correlation matrix analysis and regression analysis. The influence of the expression of the markers on survival was analyzed using a proportional hazard model. The results of color deconvolution (A) were well correlated with the results of the staining rank (E). In the semiquantitative results (B, C, and D), the staining amount (D) tended to show a better correlation with results of color deconvolution (A). Among all data sets, color deconvolution (A) demonstrated the most preferable fit in a proportional hazard model, and the expression of Fzd2 and Fzd6 was associated with poor prognosis in glioblastoma patients.


Neuropathology | 2012

TLR4, IL-6, IL-18, MyD88 and HMGB1 are highly expressed in intracranial inflammatory lesions and the IgG4/IgG ratio correlates with TLR4 and IL-6.

Hirofumi Hirano; Takako Yoshioka; Shunji Yunoue; Shingo Fujio; Hajime Yonezawa; Tadaaki Niiro; Mika Habu; Tatsuki Oyoshi; Sei Sugata; Takashi Kamezawa; Hiroshi Arimura; Ryosuke Hanaya; Hiroshi Tokimura; Mai Tokudome; Kazunori Arita

We determined distribution of plasma cells and IgG4/IgG index and factors associated with the index in intracranial inflammatory lesions. Specimens of nine patients were analyzed immunohistochemically using antibodies against CD45, CD68, CD3, CD4, CD8, CD20, CD138, lambda chain, kappa chain, IgG, IgG4, IL‐1α, IL‐6, IL‐18, toll‐like receptor (TLR) 2, TLR4, high‐mobility group box 1 (HMGB1), tumor necrosis factor‐alpha (TNF‐α), myeloid differentiation factor 88 (MyD88), and anaplastic lymphoma kinase (ALK). The relationship between all the factors was assessed using Spearmans rank correlation coefficient (ρ). Negative ALK staining was observed in all the patients. Plasma cells were detected in eight patients with varying degrees. The highest number of neutrophils, but no plasma cells, was observed in a patient with the shortest history of inflammation. IgG4/IgG index was independent of the number of plasma cells. The index was relatively highly correlated with IL‐6 (ρ = 0.7271) and TLR4 expression (ρ = 0.7246). IL‐6 expression was highly correlated with TLR4 expression (ρ = 0.8042). IL‐18 was maximally expressed in all the patients. TLR4 expression was strong, but TRL2 expression was weak. Positive HMGB1 staining was observed in all the patients, predominantly in the nuclei, but also in the cytoplasm in four patients. The cytoplasmic expression strongly correlated with IL‐1α expression (ρ = 0.9583). The cytoplasmic colocalization of HMGB1 and IL‐1α was histologically confirmed in cells with collapsing nuclei by the double‐staining method. The IgG4/IgG indexes varied case by case. IL‐6 and TLR4 expressions may influence IgG4/IgG index. The nuclei of cells with both IL‐1α and HMGB1 expressions in the cytoplasm collapse in the cell death stage. The cooperative high expression of TLR4, IL‐6, IL‐18, MyD88 and HMGB1 suggest their critical roles in the inflammation circuit.


Brain Tumor Pathology | 2011

Pineal mixed germ cell tumor with a synchronous sellar lesion in the sixth decade

Manoj Bohara; Hirofumi Hirano; Hiroshi Tokimura; Ryosuke Hanaya; Hajime Yonezawa; Francia Campos; Kazuhiko Sugiyama; Sei Sugata; Kazunori Arita

Intracranial germ cell tumors (GCTs) typically affect children and adolescents. We here report on a 59-year-old male patient presenting with diplopia, polydipsia and polyuria. On clinical examination, slight restriction of the upward gaze was seen on the left side. Computed tomography demonstrated calcifications in the pineal region and enhanced neurohypophysis. Magnetic resonance imaging displayed a heterogeneous pineal mass of 3-cm diameter, which was multicystic with an enhanced cyst wall, and also swelling of the pituitary stalk. The pineal lesion of the tumor, which included calcifications and keratinaceous components, was totally excised using an occipital transtentorial approach. Histopathological examination showed it to be a mixed GCT with germinoma and mature teratoma components. Postoperative chemoradiotherapy provided complete disappearance of the suprasellar lesion. To our knowledge, this is the first case of mixed bifocal GCT in an older adult reported in the literature, although a few cases of tumors with a single histological component have been reported. Hence, our case further underlines the possibility of the occurrence of GCTs in older adults and advocates the consideration of GCTs in the differential diagnosis of such cases for appropriate management.


British Journal of Neurosurgery | 2015

Improvement in treatment results of glioblastoma over the last three decades and beneficial factors

Hiroto Kawano; Hirofumi Hirano; Hajime Yonezawa; Shunji Yunoue; Kazutaka Yatsushiro; Mikio Ogita; Yoshiyuki Hiraki; Hiroyuki Uchida; Mika Habu; Shingo Fujio; Tatsuki Oyoshi; Yuriz Bakhtiar; Sei Sugata; Hitoshi Yamahata; Ryousuke Hanaya; Hiroshi Tokimura; Kazunori Arita

Abstract Background. The purpose of this study is to elucidate the trend of glioblastoma outcome and scrutinize the factors contributing to better outcome over three decades. Methods. Survival time and the influencing factors were retrospectively analyzed in 223 newly diagnosed primary glioblastoma patients during 1980–2010. Appraised factors included age, sex, tumor site, year of surgery, extent of resections, use of surgery supporting system, Karnofsky Performance Status (KPS), chemotherapy, conventional external beam radiotherapy (EBRT), and CyberKnife stereotactic radiotherapy (CK-SRT) use. Results. The median survival time (MST) in all patients was 13.6 months. The MSTs for 4 periods were 9.8 (1980–1990), 13.7 (1991–2000), 12.9 (2001–2005), and 15.8 months (2006–2010), respectively (p = 0.0047). Total resection, subtotal resection, partial resection, and biopsy had MSTs of 31.8, 13.9, 11.4, and 7.0 months, respectively (p < 0.0001). Regarding chemotherapy, MSTs of the temozolomide base group and nimustine hydrochloride (ACNU) base group were 16.9 and 14.6 months, respectively, whereas the MST of patients without chemotherapy was only 9.8 months (p < 0.0001). The MSTs for 40-Gy EBRT plus CK-SRT and 60-Gy EBRT were 19.1 and 10.7 months, respectively (p < 0.0001). But in sub-selected patients, treated during 2001–2010, whose resection rate was total resection or subtotal resection, EBRT was completed and postoperative KPS was greater than or equal to 70, the MST with and without CK-SRT was 26.6 and 18.3 months, respectively (p = 0.1529). According to the Cox proportional hazards model, degree of resection, KPS, ACNU use, temozolomide use, bevacizumab use, EBRT dose, and CK-SRT use were good prognostic factors. Use of neuronavigation and use of intraoperative magnetic resonance imaging were related to higher resection rate, but not determined as prognostic factors. Conclusions. We observed a gradual improvement in glioblastoma outcome, presumably because of improvements in therapeutic modalities for surgery, anticancer agents, and radiation, but the efficacy of CK-SRT remains unclear.


Surgical Neurology International | 2012

Primary malignant melanoma in the pineal region treated without chemotherapy.

Yoshinari Shinsato; Tomoko Hanada; Takao Kisanuki; Hajime Yonezawa; Shunji Yunoue; Takako Yoshioka; Ryosuke Hanaya; Hiroshi Tokimura; Hirofumi Hirano; Kazunori Arita

Background: Primary pineal malignant melanomas are uncommon intracranial tumor. Here we discuss and review a case of primary pineal malignant melanoma over its feature of imaging studies, pathological findings, and management. Case Description: A 49-year-old woman receiving renal dialysis underwent computed tomography due to a 4-month history of tinnitus and hearing disturbance. A high-density 35-mm diameter tumor was detected in the pineal region; there was obstructive hydrocephalus. The tumor was heterogeneously hyperintense on T1-weighted magnetic resonance images, iso- and low-mixed intense on T2-weighted images with hemorrhagic components, and very low-intense on T2* images. A tumor was subtotally removed via the occipital transtentorial approach. Histologically, it consisted of densely proliferated spindle-shaped or polygonal cells with rich cytoplasmic melanin. The neoplastic cells manifested cellular pleomorphism, nuclear atypia, and mitosis (3/10 high-power fields) and were immunopositive for HMB45, Melan-A, and S100 protein. The MIB-1 index was 17.4%. Whole-body 18-fluoro-deoxyglucose positron emission tomography did not demonstrate any sites with hyper uptake. Examination of the skin and mucosa identified no lesions suggestive of melanoma. She underwent treatment with the whole brain and extended local boost irradiation. Chemotherapy was not delivered due to renal failure. Follow-up imaging studies showed no recurrence or distant lesions 56 weeks after surgery. Conclusion: We report a rare case of primary pineal malignant melanoma with prolonged survival of more than 56 weeks after subtotal tumor resection followed by whole-brain and extended local irradiation without chemotherapy. Radiotherapy without chemotherapy might be sufficient for the treatment of this tumor.


Surgical Neurology International | 2012

Posterior fossa immature teratoma in an infant with trisomy 21: A case report and review of the literature.

Yuriz Bakhtiar; Hajime Yonezawa; Manoj Bohara; Ryosuke Hanaya; Yasuhiro Okamoto; Kazuhiko Sugiyama; Takako Yoshioka; Kazunori Arita

Background: Intracranial teratoma associated with Down syndrome is rare. With only three previously reported cases, our case is the first one presenting an immature component. Case Description: A 2-month-old boy with trisomy 21 presented with lethargy and head enlargement. A magnetic resonance imaging (MRI) study showed an obstructive hydrocephalus with 0.5 cm posterior fossa tumor compressing the cerebellum. The tumor revealed a mixed intensity on T1- and T2-weighted MRI images and was surrounded by peritumoral cysts. It was heterogeneously enhancing and showed multinodular mass. The tumor was gross totally removed via suboccipital craniotomy and histologically diagnosed as immature teratoma. Four cycles of chemotherapy consisting of cisplatin and etoposide followed the surgery. The radiotherapy was withheld due to infancy. Recurrent lesions in the tumor bed were noted 10 months later. They were removed in the second surgery and histologically identified as mature teratoma. Conclusion: Maturation of immature teratoma may be a result of natural conversion of multipotent embryonal cells into mature tissues and following chemotherapy.


Molecular and Clinical Oncology | 2017

Efficacy of bevacizumab therapy for unresectable malignant glioma: A retrospective analysis

Hajime Yonezawa; Hirofumi Hirano; Hiroyuki Uchida; Mika Habu; Ryosuke Hanaya; Tatsuki Oyoshi; Yuko Sadamura; Tomoko Hanada; Hiroshi Tokimura; Fm Moinuddin; Kazunori Arita

Bevacizumab (BEV), an inhibitor of vascular endothelial growth factor A, has been used for primary and recurrent malignant gliomas in Japan since June, 2013. Previous randomized controlled studies demonstrated that BEV prolonged the progression-free survival, but not the overall survival (OS) of patients with newly diagnosed glioblastoma. The aim of the present study was to elucidate the effect of BEV on the OS of patients with unresectable malignant gliomas. Of the 440 cases of malignant glioma initially treated in our institute between 2000 and 2015, 88 were not suitable for maximal resection due to patient age, physical condition, tumor location and extent, or the patients wishes. Based on the biopsy results, the pathological diagnosis was glioblastoma, anaplastic astrocytoma and anaplastic oligodendroglioma in 60, 19 and 9 patients, respectively. Kaplan-Meier and log-rank analyses were performed to investigate the effect of BEV on OS. OS was longer in the BEV group (n=24) compared with that in the non-BEV group [n=64; median survival time (MST), 566 vs. 243 days, respectively; hazard ratio (HR)=0.413; 95% confidence interval (CI): 0.216-0.787; P=0.003]. In the 41 patients who received temozolomide (TMZ) and radiotherapy and the 31 patients with glioblastoma who received TMZ and radiotherapy, OS was longer in the BEV group compared with that in the non-BEV group (MST, 568 vs. 334 days, HR=0.404, 95% CI: 0.175-0.933, P=0.016; and MST, 566 vs. 160 days, HR=0.253, 95% CI: 0.099-0.646, P=0.001, respectively). In the Cox hazard model analysis of 41 patients who underwent TMZ-based chemoradiotherapy after biopsy, the use of BEV was the strongest independent beneficial factor associated with prolonged OS (HR=0.101; P=0.0002). Our retrospective survey suggested that BEV prolongs the OS of patients with unresectable malignant gliomas. However, these results must be verified by a well-designed prospective randomized controlled trial.


Neuropathology | 2017

Calcifying pseudoneoplasm of the neuraxis in direct continuity with a low-grade glioma: A case report and review of the literature: CAPNON associated with low-grade glioma

Nayuta Higa; Hideaki Yokoo; Hirofumi Hirano; Hajime Yonezawa; Tatsuki Oyoshi; Yuko Goto; Kazunori Arita

Calcifying pseudoneoplasms of the neuraxis (CAPNON) are presumed to be a non‐neoplastic reactive pathology, based on the frequent finding of granulomatous inflammation. To our knowledge, there are few reports of CAPNON in association with a neoplasm. Here, we report the case of a 62‐year‐old man presenting with headache, which was caused by CAPNON in the left cingulate gyrus. CT scan revealed a calcified mass exhibiting gradual growth and increasing peritumoral edema. MRI showed an intra‐axial hypointense mass on T1‐ and T2‐weighted images. Development of a peri‐lesional hyperintense lesion on T2‐weighted images suggested local edema or tumoral invasion. Gadolinium‐enhanced T1‐weighted images revealed mild peripheral enhancement of the calcified nodule. L‐methyl‐11C methionine‐positron emission tomography revealed the uptake of tracer in the calcified nodule. The calcified mass and its enveloping brain tissue were removed using a parietal craniotomy. The calcified tissue was surrounded by spindle‐shaped cells positive for GFAP and nestin. The MIB‐1 labeling index of spindle cells was around 10% (i.e. a hot spot). Fourteen months after surgery, gadolinium‐enhanced MRI evidenced growth of a tiny residual lesion. Therefore, this report illustrates a potential case of CAPNON arising from low‐grade glial neoplasm.


Brain Tumor Pathology | 2013

Mature posterior fossa teratoma mimicking dermoid cyst

Manoj Bohara; Hajime Yonezawa; Prasanna Karki; Yuriz Bakhtiar; Hirofumi Hirano; Ikumi Kitazono; Nozomu Matsuyama; Kazunori Arita

We describe a very rare case of mature posterior fossa teratoma in an adult who presented with clinico-radiological findings consistent with a dermoid cyst. A computed tomography scan showed a hypodense mass in the cistern magna with calcification and a sinus tract in the occipital bone. Magnetic resonance imaging revealed a hypo- to hyperintense mass without contrast enhancement. The intraoperative picture showed a dermal sinus and a cyst containing lipid, keratin and hair. Histopathological examination showed a tumor with components of all the three germ layers; thereby, a diagnosis of mature teratoma was made. The histopathological differentiation between teratoma and dermoid cyst is very valuable for ruling out the presence of immature/malignant or germinomatous components that would require further adjuvant therapies. Thus, we here present a rare case of posterior fossa teratoma mimicking dermoid cyst and emphasize the importance of histopathological differentiation between these entities.


Rivista Di Neuroradiologia | 2017

Radiologic and histologic features of the T2 hyperintensity rim of meningiomas on magnetic resonance images.

Hiroyuki Uchida; Hirofumi Hirano; F M Moinuddin; Ryosuke Hanaya; Yuko Sadamura; Hiroshi Hosoyama; Hajime Yonezawa; Hiroshi Tokimura; Hitoshi Yamahata; Kazunori Arita

A hyperintensity rim is often seen at the brain–tumor interface of meningiomas upon T2-weighted (T2WI) magnetic resonance imaging (MRI), and it is referred to as the cerebrospinal fluid (CSF) space; however, the true nature of the rim remains unclear. We surveyed the MRI findings and the histopathologic characteristics of such rims. Our study population consisted of 53 consecutive patients who underwent meningioma removal at our hospital. The intensity of the rim on MRI scans obtained with different imaging sequences was assessed in all patients. We used 22 tumors for histopathologic investigation: tissue samples were acquired from both the tumor surface and from a deep intratumoral site. Of the 53 meningiomas, 37 (69.8%) manifested a hyperintensity rim on T2WI (T2-rim). The other 16 showed neither a hyperintense nor a hypointense rim on their T2WI. An enhancement effect corresponding to the rim was observed in 28 of the 37 (75.7%) T2-rim positive tumors. While 9 among the 37 tumors with a T2-rim (24.3%) did not show rim enhancement, they showed low intensity on fluid-attenuated inversion recovery (FLAIR) images. The microvascular density in the tumor capsule was significantly greater in the 12 T2-rim and rim enhancement positive tumors than in 10 tumors that were T2-rim negative or T2-rim positive, but rim enhancement-negative (p < 0.001, Mann–Whitney U test). We found that 75.7% of T2 hyperintense rims that were detected at the brain–meningioma interface reflected a microvascular-rich capsule layer, rather than the CSF space.

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