Yoichi Nakazato

Publications (131)425.18 Total impact

• Article: Cytoplasmic iron deposition is associated with the expression of oxidative DNA damage marker in meningiomas.

  Masaya Nagaishi, Hideaki Yokoo, Tadashi Osawa, Sumihito Nobusawa, Yuko Tanaka, Hayato Ikota, Yuhei Yoshimoto, Yoichi Nakazato
  [show abstract] [hide abstract]
  ABSTRACT: Angiomatous meningiomas are rare meningioma subtypes, which are characterized by abundant, well-formed vessels. We encountered two cases of newly diagnosed angiomatous meningiomas exhibiting tumor cells with brown pigments, which were histochemically proven to be iron. In an attempt to understand its pathological significance, we assessed this unusual finding in representatives for each grade of meningiomas and immunoexpression of transferrin receptor (CD71) and the oxidative DNA damage marker, 8-hydroxy-2'-deoxyguanosine (8-OHdG). Iron deposition in the tumor cells was observed in 8/15 (53%) angiomatous meningioma cases, 2/6 (33%) microcystic meningiomas and 2/20 (10%) meningothelial meningiomas, which included clustered microvessels, but not in fibrous, atypical or anaplastic meningiomas (P = 0.001). Cytoplasmic CD71 expression was largely negative in angiomatous meningioma cases, but positive in meningothelial and high-grade meningiomas, suggesting that the transferrin-dependent iron transporter was involved in iron uptake in meningiomas. Nuclear expression of 8-OHdG was observed in ≥50% of the tumor cells in all 15 cases of angiomatous meningioma and was associated with the presence of regressive histopathological findings, such as hyalinized vessels and cystic changes. In addition, the fraction of iron-containing tumor cells was correlated to those expressing 8-OHdG (P = 0.005). Our finding indicates that cytoplasmic iron deposition in tumor cells is characteristic of highly vascularized benign meningiomas and related to increased oxidative DNA damage markers.
  Neuropathology 02/2013; · 2.02 Impact Factor
• Article: Characterization of microglia/macrophages in gliomas developed in S-100β-v-erbB transgenic rats.

  Atsushi Sasaki, Hideaki Yokoo, Yuko Tanaka, Taku Homma, Yoichi Nakazato, Hiroko Ohgaki
  [show abstract] [hide abstract]
  ABSTRACT: Glioma-infiltrating microglia/macrophages are referred to as tumor-associated macrophages (TAMs). Transgenic (TG) rats expressing v-erbB, which is a viral form of the epidermal growth factor receptor, under transcriptional regulation by the S100-β promoter, develop brain tumors. This study was designed to clarify the pathological characteristics of TAMs in these experimental tumors. We carried out immunohistochemical and morphometrical analyses of microglia/macrophages in brain tumors (5 malignant glioma, 4 anaplastic oligodendroglioma, 4 astrocytoma) that developed in TG rats. TAMs with ionized calcium-binding adaptor molecule 1 (Iba1) positivity and morphology of activated, non-phagocytic microglia increased within and around the tumors in malignant gliomas and anaplastic astrocytomas. The Iba1-positive TAMs of the tumor core were significantly more activated than Iba1-positive microglia of non-neoplastic brain tissue in intraparenchymal anaplastic oligodendrogliomas. Iba1 expression showed a significant positive correlation to Ki-67 expression in all the gliomas. Most TAMs showed no or little expression against CD68, CD163 or CD204, although CD204-positive TAMs were observed in necrosis as well as in the proliferating vascular wall. In conclusion, S-100β-v-erbB TG rats may serve as a useful animal model for further analysis of TAMs in terms of tumor cell proliferation, microvascular proliferation and phagocytosis, and as a tool for therapeutic use in malignant gliomas, although it should be noted that the polarization of TAMs toward the M2 phenotype remains unclear.
  Neuropathology 01/2013; · 2.02 Impact Factor
• Article: Intradural extramedullary spinal nerve sheath myxoma: a report of two cases.

  Mariko Yamato, Hayato Ikota, Junya Hanakita, Yoichi Iizuka, Yoichi Nakazato
  [show abstract] [hide abstract]
  ABSTRACT: Nerve sheath myxoma, a myxoid variant of schwannoma, is a dermal tumor that usually occurs in the upper extremities, head and neck region, or trunk; occasionally, however, it has also been reported to develop in the spinal canal. Here, we describe two cases of intraspinal nerve sheath myxoma. Case 1 was a 74-year-old man with left hypochondrial pain. Gadolinium-enhanced magnetic resonance imaging (MRI) of his spine revealed a well-demarcated intradural extramedullary tumor with peripheral enhancement at the Th8 level. Case 2 was a 58-year-old man with lower back and left buttock pain. Gadolinium-enhanced MRI revealed a well-demarcated intradural extramedullary tumor with peripheral enhancement at the Th12-L1 level. Both cases were clinically diagnosed as schwannoma. Histological studies revealed characteristic myxoid lobules which were separated by fibrous septa or bands of more compact cellular area. The tumor cells were diffusely positive for S-100 and focally positive for Schwann/2E, which reacts with Schwann cells and myelin in the peripheral nervous system. The positive reaction to Schwann/2E confirmed the occurrence of peripheral nerve sheath differentiation. Nerve sheath myxoma should be included in differential diagnosis of spinal canal tumors.
  Brain Tumor Pathology 01/2013; · 1.19 Impact Factor
• Article: PDGFRA Gain in Low-Grade Diffuse Gliomas.

  Kazuya Motomura, Michel Mittelbronn, Werner Paulus, Benjamin Brokinkel, Kathy Keyvani, Ulrich Sure, Karsten Wrede, Yoichi Nakazato, Yuko Tanaka, Naosuke Nonoguchi, Daniela Pierscianek, Young-Ho Kim, Luigi Mariani, Anne Vital, Arie Perry, Hiroko Ohgaki
  [show abstract] [hide abstract]
  ABSTRACT: Glioblastomas with a proneural expression signature are characterized by frequent IDH1 mutations (i.e. genetic hallmarks of secondary glioblastomas) and PDGFRA (platelet-derived growth factor receptor-α) amplification. Mutations in IDH1/2 are frequent and early genetic events in diffuse astrocytomas (World Health Organization grade II), precursor to secondary glioblastomas, but little is known about the role and timing of PDGFRA amplification in these tumors. We assessed PDGFRA gain in 342 low-grade diffuse gliomas by quantitative polymerase chain reaction. Gain in PDGFRA was detected in 27 (16.3%) of 166 diffuse astrocytomas, significantly more frequent than in oligodendrogliomas (3 [2.6%] of 115, p < 0.0001). Analyses using previously published data from our laboratory showed an inverse correlation between PDGFRA gain and IDH1/2 mutations (p = 0.018) or 1p/19q loss (p < 0.0001). The vast majority of diffuse astrocytomas showed IDH1/2 mutations and/or PDGFRA gain (154 [93%] of 166). Mean survival of diffuse astrocytoma patients with PDGFRA gain was 8.8 ± 1.6 years, similar to that with IDH1/2 mutations (7.8 ± 0.5 years) or TP53 mutations (7.6 ± 0.6 years) but significantly longer than those with MET gain (4.4 ± 0.7 years). Dual-color fluorescence in situ hybridization in 6 diffuse astrocytomas with PDGFRA/MET co-gain identified by quantitative polymerase chain reaction revealed that PDGFRA and MET were typically amplified in different tumor cell populations. Tumor cells with coamplification were also focally observed, suggesting intratumoral heterogeneity, even in diffuse astrocytomas.
  Journal of neuropathology and experimental neurology. 12/2012;
• Article: Encephalopathy with amyloid angiopathy and numerous amyloid plaques with low levels of CSF Aβ1-40/Aβ1-42.

  Masaki Ikeda, Kimitoshi Hirayanagi, Motonobu Arai, Satoko Kakuda, Kouki Makioka, Natsumi Furuta, Eriko Takai, Hiroo Kasahara, Setsuki Tsukagoshi, Yukio Fujita, Masakuni Amari, Masamitsu Takatama, Yoichi Nakazato, Koichi Okamoto
  [show abstract] [hide abstract]
  ABSTRACT: A middle-aged male suffering from encephalopathy with cerebral amyloid angiopathy (CAA) with amyloid beta (Aβ) presented with initial symptoms of transient consciousness disturbance and left visual field photophobia. Lesions with aberrantly high signal on T2-weighted magnetic resonance imaging (MRI) of the brain appeared in the right temporal lobe posterior to the occipital lobe and spread to other areas. Brain biopsy revealed Aβ deposits in vascular walls and numerous diffuse plaques in parenchymal areas. Based on MRI findings, Initial corticosteroid therapy with beta methasone effectively improved the neurological symptoms of consciousness disturbance and motor deficits. After corticosteroid therapy was stopped at 4 weeks, recurrence occurred. Additional corticosteroids did not improve clinical symptoms and the patient progressed to a bed-ridden state with a severe consciousness disturbance. Notably, CSF Aβ1-42 and CSF Aβ1-40 decreased while the recurrent encephalopathy worsened. After intense deterioration, the patient became stable. CSF Aβ1-42 increased but remained at a very low level. This case of CAA encephalopathy with apolipoprotein E ϵ4/ϵ4 homozygosity showed Aβ deposits in vascular walls and numerous diffuse plaques in parenchymal areas. The clinical course suggests that reduction of CSF Aβ1-42 and Aβ1-40 might be related to clinical deterioration in cases of encephalopathy.
  Amyloid: the international journal of experimental and clinical investigation: the official journal of the International Society of Amyloidosis 09/2012; · 2.12 Impact Factor
• Article: Cerebral astroblastoma in an adult: An immunohistochemical, ultrastructural and genetic study.

  Yong-Juan Fu, Yoshinori Taniguchi, Shigekazu Takeuchi, Atsushi Shiga, Kouichirou Okamoto, Junko Hirato, Sumihito Nobusawa, Yoichi Nakazato, Akiyoshi Kakita, Hitoshi Takahashi
  [show abstract] [hide abstract]
  ABSTRACT: Astroblastoma is a rare glial tumor of unknown origin, usually affecting the cerebral hemispheres of children and young adults. Here we report an unusual cerebral tumor in a 60-year-old woman. On MRI, the tumor appeared as a well circumscribed lesion in the left frontal lobe. Histopathologically, it was composed of rounded eosinophilic cells, and was divisible into two areas. One area was characterized by a collection of GFAP-positive cells around sclerotic blood vessels (astroblastic pseudorosettes and perivascular hyalinization), and had a Ki-67 labeling index of 2.8%. However, the other area was highly cellular, showing many GFAP-negative cells often with a rhabdoid appearance, mitoses and a Ki-67 index of 15.7%. Thus, a final diagnosis of malignant astroblastoma was made. In both areas of the tumor, nearly all the cells were positive for epithelial membrane antigen, and many were positive for oligodendrocyte transcription factor 2 (Olig2). Focal expression of cytokeratin was also evident. With regard to genetic markers, the tumor cells were positive for INI1 and negative for mutant IDH1. The p53 labeling index was <1%. Ultrastructurally, the presence of intra- and intercellular lumina with microvilli was a feature. DNA examination of IDH1/2 and TP53 showed no mutations. In conclusion, although ependymal features were evident ultrastructurally in the present tumor, the immunohistochemical expression pattern of Olig2 was that of diffuse astrocytoma. On the other hand, the absence of mutations in both IDH1/2 and TP53 suggested that the present tumor was not a purely astrocytic neoplasm. Further studies, including molecular and genetic analyses, will provide insight into the histogenesis of astroblastoma.
  Neuropathology 09/2012; · 2.02 Impact Factor
• Article: DMBT1 homozygous deletion in diffuse astrocytomas is associated with unfavorable clinical outcome.

  Kazuya Motomura, Michel Mittelbronn, Werner Paulus, Benjamin Brokinkel, Kathy Keyvani, Ulrich Sure, Karsten Wrede, Yoichi Nakazato, Yuko Tanaka, Daniela Pierscianek, Young-Ho Kim, Luigi Mariani, Anne Vital, Hiroko Ohgaki
  [show abstract] [hide abstract]
  ABSTRACT: Primary glioblastomas develop with a short clinical history, without evidence for less malignant precursor lesions, while secondary glioblastomas slowly develop via progression from diffuse astrocytoma (WHO grade II) or anaplastic astrocytoma (WHO grade III). The time until progression and the clinical outcome of diffuse astrocytomas vary significantly. We have shown that IDH1 mutations reliably distinguish between primary glioblastomas (without IDH1 mutations) and secondary glioblastomas (with IDH1 mutations). The most frequent genetic alteration shared by primary and secondary glioblastomas is loss of heterozygosity at 10q (up to 60% of cases). Here, we first assessed The Cancer Genome Atlas data to identify gene loss at 10q in glioblastomas with or without IDH1 mutations. Using log-ratio thresholds of -1.0, 10 genes were identified; with the log-ratio thresholds of -2.0, only the DMBT1 (deleted in malignant brain tumor 1) gene at 10q26.13 remained as a deleted gene in glioblastomas with or without IDH1 mutations (12.5% vs 8.0%). We then analyzed a total of 404 gliomas by differential polymerase chain reaction and found a DMBT1 homozygous deletion at a similar frequency in primary and secondary glioblastomas (19.6% vs 20.8%). A fraction (11.3%) of diffuse astrocytomas showed a DMBT1 homozygous deletion that was significantly associated with a shorter overall survival (52.8 vs 84.0 months; p = 0.003). These results indicate that a DMBT1 homozygous deletion is present in a fraction of diffuse astrocytomas and that it is associated with an unfavorable clinical outcome.
  Journal of Neuropathology and Experimental Neurology 07/2012; 71(8):702-7. · 4.26 Impact Factor
• Article: Autopsy case of delayed anaphylactic shock due to contrast medium.

  Yayoi Nagai, Yuko Tanaka, Yoichi Nakazato, Nobuyuki Sugawara, Miho Arai, Etsuko Okada, Yoshinari Koyama, Hiroshi Hinohara, Koujirou Yamamoto, Masahiko Kurabayashi, Yoshihisa Nojima, Osamu Ishikawa
  [show abstract] [hide abstract]
  ABSTRACT: We report an autopsy case of delayed anaphylactic shock due to contrast medium. A 17-year-old Japanese man underwent angiography using non-ionic contrast medium under the suspected diagnosis of Buerger's disease. Initial symptoms appeared 6 h after the administration of the contrast medium, and death was confirmed 11 h later. Considering the clinical course and the results of the autopsy, we concluded that the direct cause of the patient's death was severe acute circulatory failure due to a delayed allergic reaction to the contrast medium. The reported incidence of serious delayed reactions or biphasic reactions to non-ionic contrast medium is extremely low; however, we should be aware of such rare adverse reactions.
  The Journal of Dermatology 06/2012; 39(10):852-4. · 1.49 Impact Factor
• Article: MET Gain in Diffuse Astrocytomas is Associated with Poorer Outcome.

  Daniela Pierscianek, Young-Ho Kim, Kazuya Motomura, Michel Mittelbronn, Werner Paulus, Benjamin Brokinkel, Kathy Keyvani, Karsten Wrede, Yoichi Nakazato, Yuko Tanaka, Luigi Mariani, Anne Vital, Ulrich Sure, Hiroko Ohgaki
  [show abstract] [hide abstract]
  ABSTRACT: Glioblastoma may develop rapidly without evidence for precursor lesions (primary glioblastomas), or progress from diffuse or anaplastic astrocytomas (secondary glioblastomas). Despite having distinct genetic profiles, these glioblastoma subtypes have similar histological features. We hypothesized that the highly malignant phenotype of glioblastoma may be attributable to genetic alterations that are common to both glioblastoma subtypes. In the present study, we first searched for commonly (>35%) amplified genes in glioblastomas with IDH1 mutation (a hallmark of secondary glioblastoma) and those without IDH1 mutation (typical for primary glioblastoma) in data from The Cancer Genome Atlas (TCGA). A total of 25 genes were identified, of which 21 were located at 7q31-34. We then screened 264 gliomas (70 glioblastomas, 112 diffuse astrocytomas, 82 oligodendrogliomas) for gain of the MET at 7q31.2 with quantitative polymerase chain reaction (PCR). MET gain was detected in primary glioblastomas (47%) and secondary glioblastomas (44%), suggesting that this genetic alteration plays a role in the pathogenesis of both glioblastoma subtypes. MET gain was also common in diffuse astrocytomas (38%), but less frequent in oligodendrogliomas (16%). MET gain in diffuse astrocytomas was associated with shorter survival (median, 43.0 vs. 70.7 months; P = 0.004), suggesting that MET gain is a useful prognostic marker for diffuse astrocytomas.
  Brain Pathology 06/2012; · 3.99 Impact Factor
• Article: Frequent BRAF Gain in Low-Grade Diffuse Gliomas with 1p/19q Loss.

  Young-Ho Kim, Naosuke Nonoguchi, Werner Paulus, Benjamin Brokinkel, Kathy Keyvani, Ulrich Sure, Karsten Wrede, Luigi Mariani, Felice Giangaspero, Yuko Tanaka, Yoichi Nakazato, Anne Vital, Michel Mittelbronn, Arie Perry, Hiroko Ohgaki
  [show abstract] [hide abstract]
  ABSTRACT: Chromosomal 7q34 duplication and BRAF-KIAA1549 fusion is a characteristic genetic alteration in pilocytic astrocytomas. 7q34 gain appears to be common in diffuse astrocytomas, but its significance is unclear. We assessed BRAF gain and BRAF mutations in 123 low-grade diffuse gliomas, including 55 diffuse astrocytomas, 18 oligoastrocytomas and 50 oligodendrogliomas. Quantitative polymerase chain reaction (PCR) revealed BRAF gain in 17/50 (34%) oligodendrogliomas, a significantly higher frequency than in diffuse astrocytomas (7/55; 13%; P = 0.0112). BRAF gain was common in low-grade diffuse gliomas with 1p/19q loss (39%) and those lacking any of the genetic alterations analyzed (31%), but was rare in those with TP53 mutations (2%). Logistic regression analysis showed a significant positive association between 1p/19q loss and BRAF gain (P = 0.0032) and a significant negative association between TP53 mutations and BRAF gain (P = 0.0042). Fluorescence in situ hybridization (FISH) analysis of 26 low-grade diffuse gliomas with BRAF gain additionally revealed BRAF-KIAA1549 fusion in one oligodendroglioma. Sequencing of cDNA in 17 low-grade diffuse gliomas showed BRAF-KIAA1549 fusion in another oligodendroglioma. A BRAF(V600E) mutation was also detected in one oligodendroglioma, and a BRAF(A598V) in one diffuse astrocytoma. These results suggest that low-grade diffuse gliomas with 1p/19q loss have frequent BRAF gains, and a small fraction of oligodendrogliomas may show BRAF-KIAA1549 fusion.
  Brain Pathology 05/2012; 22(6):834-840. · 3.99 Impact Factor
• Article: Amplification of the STOML3, FREM2, and LHFP genes is associated with mesenchymal differentiation in gliosarcoma.

  Masaya Nagaishi, Young-Ho Kim, Michel Mittelbronn, Felice Giangaspero, Werner Paulus, Benjamin Brokinkel, Anne Vital, Yuko Tanaka, Yoichi Nakazato, Catherine Legras-Lachuer, Joel Lachuer, Hiroko Ohgaki
  [show abstract] [hide abstract]
  ABSTRACT: Gliosarcoma is a rare glioblastoma variant characterized by a biphasic tissue pattern with alternating areas that display either glial (glial fibrillary acidic protein-positive) or mesenchymal (reticulin-positive) differentiation. Previous analyses have shown identical genetic alterations in glial and mesenchymal tumor areas, suggesting that gliosarcomas are genetically monoclonal, and mesenchymal differentiation was considered to reflect the elevated genomic instability of glioblastomas. In the present study, we compared genome-wide chromosomal imbalances using array comparative genomic hybridization in glial and mesenchymal tumor areas of 13 gliosarcomas. The patterns of gain and loss were similar, except that the gain at 13q13.3-q14.1 (log(2) ratio >3.0), containing the STOML3, FREM2, and LHFP genes, which was restricted to the mesenchymal tumor area of a gliosarcoma. Further analyses of 64 cases of gliosarcoma using quantitative PCR showed amplification of the STOML3, FREM2, and LHFP genes in 14 (22%), 10 (16%), and 7 (11%) mesenchymal tumor areas, respectively, but not in glial tumor areas. Results of IHC analysis confirmed that overexpression of STOML3 and FREM2 was more extensive in mesenchymal than in glial tumor areas. These results suggest that the mesenchymal components in a small fraction of gliosarcomas may be derived from glial cells with additional genetic alterations.
  American Journal Of Pathology 05/2012; 180(5):1816-23. · 4.89 Impact Factor
• Article: Analysis of interleukin-6 gene expression in primary human gliomas, glioblastoma xenografts, and glioblastoma cell lines

  Atsushi Sasaki, Shogo Ishiuchi, Tsugiyasu Kanda, Masatoshi Hasegawa, Yoichi Nakazato
  [show abstract] [hide abstract]
  ABSTRACT: Our previous study showed that high-grade astrocytomas often expressed high interleukin (IL)-1β production. Coexpression of IL-1β and IL-6 has been found in a number of glioma samples and glioma cell lines. To characterize the expression of IL-6 in the human glioma microenvironment, we investigated surgically excised human gliomas, human glioblastoma xenografts, and human glioblastoma cell lines using the reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), and enzyme-linked immunosorbent assay (ELISA). In the 29 primary gliomas, transcripts of IL-6 were less frequently detectable (55.6%) than those of IL-1β (72.4%) or those of IL-10, IL-8, or IL-1α (>80% each). As for IL-6 gene expression, little or no transcription was observed in low-grade astrocytomas, oligodendroglial tumors, and 1 ependymoma. Strong IL-6 gene expression was found in only 5 of 9 glioblastomas. Immunohistochemically, IL-6 antigen was localized in the tumor cells and macrophages in 4 of 7 glioblastomas. In 3 glioblastomas transplanted into nude mice, both IL-1β and IL-6 were detected only in 1, but other cytokines (IL-8, IL-10, and IL-1α) were detected in all 3 xenografts by RT-PCR. Two cell lines both showed IL-6 expression at the mRNA level, and in a cell line with a high level of IL-6 and IL-1β transcripts, significant production of IL-6 was observed by IHC and ELISA. We concluded that IL-6 produced in tumor tissue may be involved in tumor progression in some glioblastomas, but not in low-grade astrocytomas and oligodendroglial tumors, and that IL-6 gene expression is closely correlated with IL-1β expression in biopsy tissue, xenografts, and cultures of human gliomas.
  Brain Tumor Pathology 04/2012; 18(1):13-21. · 1.19 Impact Factor
• Source

  Available from: jsnm.org

  Article: Central neurocytoma with unusually intense FDG uptake: Case report

  Toshiyuki Ohtani, Akio Takahashi, Fumiaki Honda, Shogo Ishiuchi, Hideyuki Kurihara, Tomio Inoue, Yoichi Nakazato, Tomio Sasaki
  [show abstract] [hide abstract]
  ABSTRACT: Central neurocytoma is a benign neuronal tumor with a favorable prognosis. This tumor is typically characterized by decreased uptake of18F-fluorodeoxy glucose (FDG) and any increased uptake of FDG in patients suffering from this tumor would be highly unusual. A case of central neurocytoma with an intense FDG uptake, combined with atypical histopathological features and a high proliferation index is reported in this paper. A 45-year-old male had a two months’ history of right hemiweakness. Magnetic resonance (MR) imaging showed a large tumor in the right lateral ventricle. Positron emission tomography (PET) with FDG revealed high glucose metabolism in the tumor. The histological diagnosis was central neurocytoma with atypical features characterized by microvascular proliferation. The MIB-1 labeling index, ordinarily smaller than 2.0%, was 7.0%. Conventional radiotherapy, with a total dose of 50 Gy, was administered after the surgical treatment. The patient returned to his normal daily activities after the cessation of radiation therapy.
  Annals of Nuclear Medicine 04/2012; 15(2):161-165. · 1.50 Impact Factor
• Article: Malignant transformation of ovarian mature cystic teratoma with a predominant pulmonary type small cell carcinoma component.

  Hayato Ikota, Kou Kaneko, Sachio Takahashi, Mitsue Kawarai, Yuko Tanaka, Hideaki Yokoo, Yoichi Nakazato
  [show abstract] [hide abstract]
  ABSTRACT: A 68-year-old woman was diagnosed with mature cystic teratoma of the left ovary when she was 44 years old. The tumor recently enlarged rapidly, and abdominal magnetic resonance imaging revealed an intrapelvic cystic lesion, which measured 123 × 120 × 107 mm and contained a mural nodule. Under a clinical diagnosis of malignant transformation of mature cystic teratoma, bilateral salpingo-oophorectomy with total hysterectomy and omentectomy were performed. The resected specimen showed a unilocular cystic lesion containing a well-demarcated mural nodule measuring 35 × 30 × 25 mm in the left ovary. A microscopic examination revealed various types of carcinoma in the mural nodule: pulmonary type small cell carcinoma (65%), adenocarcinoma (25%), squamous cell carcinoma (5%), and transitional cell carcinoma (5%). Small cell carcinoma was positive for CD56, synaptophysin, and chromogranin A. The adenocarcinoma component showed intestinal phenotypes; i.e. cytokeratin (CK) 7(-), CK20(+), CDX2(+), estrogen receptor(-), and progesterone receptor (-). Interestingly, CDX2 positivity was retained in all of the carcinomas. It was assumed that the adenocarcinoma had arisen from an intestinal epithelium in the mature cystic teratoma and then differentiated into the diverse histological types mentioned above.
  Pathology International 04/2012; 62(4):276-80. · 1.62 Impact Factor
• Article: Activation and alteration of lysosomes in multiple system atrophy.

  Kouki Makioka, Tsuneo Yamazaki, Masamitsu Takatama, Yoichi Nakazato, Koichi Okamoto
  [show abstract] [hide abstract]
  ABSTRACT: Multiple system atrophy (MSA) is a sporadic neurodegenerative disorder. Its histopathological features include glial cytoplasmic inclusions that contain α-synuclein as the main component. Recently, multiple lines of evidence have suggested a role for lysosomes in the pathogenesis of many neurodegenerative diseases. To elucidate whether lysosomes are also implicated in the pathology of MSA, we carried out an immunohistochemical study using antibodies against lysosomal proteins in the brains of patients with MSA and in control brains. A robust increase in the expression and an alteration in the morphology and distribution of lysosomal-protein-positive structures were observed in MSA brains. Double immunohistochemistry demonstrated that lysosomal markers did not colocalize mainly with glial cytoplasmic inclusions, but colocalized with a microglial marker. These immunohistochemical signatures suggest that lysosomes are activated in microglia during the disease process, and play a pivotal role in the pathology of MSA.
  Neuroreport 03/2012; 23(5):270-6. · 1.66 Impact Factor
• Article: Phagocytized corpora amylacea as a histological hallmark of astrocytic injury in neuromyelitis optica.

  Aya Suzuki, Hideaki Yokoo, Akiyoshi Kakita, Hitoshi Takahashi, Yasuo Harigaya, Hayato Ikota, Yoichi Nakazato
  [show abstract] [hide abstract]
  ABSTRACT: Neuromyelitis optica (NMO) is an inflammatory demyelinating and necrotizing disorder of the CNS that mainly affects the optic nerve and spinal cord. The etiology is still uncertain; however, the discovery of serum anti-aquaporin-4 (AQP4) autoantibody is becoming the center of attention, and a new hypothesis is emerging that NMO is essentially astrocytopathy provoked by this autoantibody. In this study, we focused on corpora amylacea (CA), glycoproteinaceous inclusions in astrocytic processes. We examined 57 lesions in nine cases of NMO spectrum disorder, and demonstrated that CA were phagocytized by macrophages in 42 lesions (74%) of eight cases, while phagocytized figures were not seen in unaffected areas. Phagocytized CA were frequently encountered in early-phase lesions still retaining myelin structures, while fewer or none were found in chronic destructive lesions. Moreover, phagocytized CA were significantly smaller in diameter than intact ones, and CA were decreased or absent in most lesions assessed. These findings suggest the following pathophysiological process: the astrocytes are affected at an early phase in NMO, CA are expelled from the astrocytes and phagocytized by macrophages finally leading to clearance. A phagocytized figure and subsequent loss of CA can be a histological hallmark of astrocytic injury of NMO.
  Neuropathology 02/2012; · 2.02 Impact Factor
• Article: Erratum to: Rapid progression of rhabdoid components of a composite high-grade glioma and rhabdoid tumor in the occipital lobe of an adult.

  Junkoh Yamamoto, Mayu Takahashi, Yoshiteru Nakano, Yoshiteru Soejima, Takeshi Saito, Daisuke Akiba, Junko Hirato, Yoichi Nakazato, Shigeru Nishizawa
  Brain Tumor Pathology 02/2012; · 1.19 Impact Factor
• Article: Nestin expression in brain tumors: its utility for pathological diagnosis and correlation with the prognosis of high-grade gliomas.

  Hideo Arai, Hayato Ikota, Ken-ichi Sugawara, Sumihito Nobusawa, Junko Hirato, Yoichi Nakazato
  [show abstract] [hide abstract]
  ABSTRACT: One of the type VI intermediate filament proteins, nestin, is expressed in neuroepithelial stem cells during neural embryogenesis. Nestin is also expressed in a variety of neoplasms. Its expression in brain tumors has not been thoroughly studied. The objectives of this study were to survey nestin expression in different types of brain tumor, and to evaluate nestin as a marker for diagnosis and prognosis. We used tissue microarrays of 257 brain tumors for an immunohistochemical overview of nestin expression: nestin was frequently expressed in gliomas and schwannomas. Most of the gliomas that expressed high levels of nestin were high-grade gliomas (anaplastic astrocytomas, anaplastic oligodendrogliomas, anaplastic oligoastrocytomas, and glioblastomas). We then focused on high-grade gliomas and performed immunohistochemistry again, using whole-mount slides. As a result, we found (1) significantly different nestin expression between glioblastomas and other high-grade gliomas, and (2) worse overall survival for high-grade gliomas with high nestin expression. Our results suggest that: (1) nestin is a useful marker for diagnosis of high-grade gliomas, (2) nestin is helpful in diagnosis of schwannomas, and (3) nestin expression is related to poor prognosis in high-grade gliomas.
  Brain Tumor Pathology 02/2012; 29(3):160-7. · 1.19 Impact Factor
• Article: Frequent IDH1/2 mutations in intracranial chondrosarcoma: a possible diagnostic clue for its differentiation from chordoma.

  Motohiro Arai, Sumihito Nobusawa, Hayato Ikota, Sunao Takemura, Yoichi Nakazato
  [show abstract] [hide abstract]
  ABSTRACT: Mutations in the genes encoding isocitrate dehydrogenase (IDH) 1/2 have been detected in a significant proportion of diffuse gliomas and in a small fraction of acute myeloid leukemia (AML) cases. Recently, in an examination of various types of mesenchymal tumor, IDH1/2 mutations were only found in cartilaginous tumors including central conventional and periosteal enchondromas/chondrosarcomas. The frequency of IDH1/2 mutations was 56%, and the IDH1 R132C mutation, which is not common in diffuse gliomas or AML, accounted for 40% of these mutations. In this study, we investigated the IDH1/2 mutation status of intracranial chondrosarcomas and chordomas, which are morphologically similar and affect similar regions of the cranial cavity. Of the 13 chondrosarcomas analyzed, six (46.1%) displayed IDH1/2 mutations (the predominant type was IDH1 R132C). Also, an IDH2 mutation (R172S) was observed in one case. Conversely, none of the ten chordomas analyzed displayed any IDH1 or IDH2 mutations. Our data suggest that the IDH1/2 mutation status could be valuable for distinguishing intracranial chondrosarcomas from chordomas.
  Brain Tumor Pathology 02/2012; · 1.19 Impact Factor
• Article: Analysis of chromosome 19q13.42 amplification in embryonal brain tumors with ependymoblastic multilayered rosettes.

  Sumihito Nobusawa, Hideaki Yokoo, Junko Hirato, Akiyoshi Kakita, Hitoshi Takahashi, Takashi Sugino, Kazuhiro Tasaki, Hideaki Itoh, Tsutomu Hatori, Yoshie Shimoyama, Atsuko Nakazawa, Shigeru Nishizawa, Hiroshi Kishimoto, Keiko Matsuoka, Masahiro Nakayama, Naoki Okura, Yoichi Nakazato
  [show abstract] [hide abstract]
  ABSTRACT: Recently, it was reported that ependymoblastoma and embryonal tumor with abundant neuropil and true rosettes (ETANTR) show 19q13.42 amplification at a high frequency, suggesting that these tumors may constitute a single entity. As ependymoblastic rosettes are the most prominent features in both subtypes, embryonal tumor with multilayered rosettes (ETMR) was proposed, for which 19q13.42 amplification represents a specific molecular hallmark. However, ependymoblastic rosettes are not specific to ependymoblastoma and ETANTR, and are also found in a few other embryonal tumors as well as immature teratomas, and knowledge on 19q13.42 amplification in these tumors is limited. In this study, we performed fluorescence in situ hybridazation (FISH) analysis and differential polymerase chain reaction (PCR), and detected 19q13.42 amplification in three out of four ETANTR, one ependymoblastoma and one medulloepithelioma with ETANTR components, whereas none of the two atypical teratoid/rhabdoid tumors (AT/RT) with ependymoblastic rosettes nor two immature teratomas with developing neuroectodermal structures showed such amplification, suggesting that medulloepitheliomas would possibly be included in ETMR, and ependymoblastic rosettes in AT/RT do not signify that these tumors constitute ETMR. Also, we found C19MC rather than miR-371-373 was amplified in one ETANTR, suggesting that C19MC miRNA cluster seems to be more closely linked to the pathogenesis of ETMR.
  Brain Pathology 02/2012; 22(5):689-97. · 3.99 Impact Factor