Toru Motoi

Tokyo Metropolitan Cancer and Infectious Diseases Center, Edo, Tōkyō, Japan

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Publications (37)84.98 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: A patient who had a primary undifferentiated high-grade pleomorphic sarcoma/malignant fibrous histiocytoma that apparently arose in the mandible, but showed uncertain differentiation on histopathological examination, is described. Our regimen, a combination of pre- and postoperative chemotherapy and surgical resection, produced a good outcome.
    International Journal of Oral Science 01/2014; · 2.72 Impact Factor
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    ABSTRACT: Angiofibroma of soft tissue is a recently described soft tissue tumor that is characterized by fibroblastic spindle tumor cells with arborizing capillary proliferation. Cytogenetically, it harbors a specific fusion gene involving the nuclear receptor coactivator 2 (NCOA2) gene. We report here additional new pathological and cytogenetic features. A soft tissue tumor in the left thigh of 73‐year‐old female was investigated. Microscopically, histiocytoid tumor cells were scattered in an edematous background with branching capillary proliferation. Immunohistochemically, we identified that the tumor cells were positive for histiocytic markers such as CD68 and CD163. Rearrangement of the NCOA2 gene was detected successfully by chromogenic in situ hybridization; however, abnormal signal patterns were observed in only a small subset of tumor cells. Unlike typical tumors with bland spindle cells, the present tumor needs to be distinguished from myxoid, dendritic and clear cell tumors. This case may suggest that angiofibroma of soft tissue is not in the center of the fibroblastic/myofibroblastic tumor group, but rather shows a fibrohistiocytic nature. We also found intratumor genetic heterogeneity, which is uncommon for a translocation‐associated tumor. Therefore, careful evaluation is required to detect the gene rearrangement in this tumor entity.
    Pathology International 01/2014; 64(5). · 1.72 Impact Factor
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    ABSTRACT: Myxoid liposarcomas (MLSs) are characterized by t(12;16)(q13;p11) translocation and expression of TLS-CHOP chimeric oncoprotein. However, the molecular functions of TLS-CHOP have not been fully understood. On the other hand, microRNAs (miRNAs) comprise an abundant class of endogenous small non-coding RNAs that negatively regulate the expression of their target genes, and are involved in many biological processes. It is now evident that dysregulation of miRNAs is an important step in the development of many cancers. To our knowledge, however, there have been no reports of the miRNAs involved in MLS tumorigenesis and development. In this study, we have found that miR-486 expression was repressed in TLS-CHOP-expressed NIH3T3 fibroblasts and MLS tissues, and exogenous overexpression of miR-486 repressed growth of MLS cells. Thus, downregulation of miR-486 may be an important process for MLS. In addition, we have identified plasminogen activator inhibitor-1 (PAI-1) as a novel target gene of miR-486. PAI-1 is a unique type of serine protease inhibitor and is known to be one of the key regulators of tumor invasion and metastasis. Furthermore, knockdown of PAI-1 by a specific small interfering RNA (siRNA) inhibited growth of MLS cells, suggesting that increased expression of PAI-1 by miR-486 repression is critical for survival of MLS cells. Collectively, these results suggest a novel essential molecular mechanism that TLS-CHOP activates PAI-1 expression by repression of miR-486 expression in MLS tumorigenesis and development.
    Biochemical and Biophysical Research Communications 09/2012; 427(2):355-60. · 2.41 Impact Factor
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    ABSTRACT: Low-grade osteosarcomas comprise a distinct subset of osteosarcomas. They may occasionally dedifferentiate into high-grade tumors, typically in the form of high-grade osteosarcoma, which are histologically indistinguishable from conventional osteosarcomas. MDM2 and CDK4 are often amplified in low-grade osteosarcomas and their dedifferentiated counterparts, and the encoded proteins are accordingly overexpressed. As MDM2/CDK4 expression was reportedly rare in conventional osteosarcoma, we hypothesized that these markers may help separate dedifferentiated osteosarcoma from the conventional type. To test this, we performed MDM2 and CDK4 immunohistochemistry on 81 primary and 26 recurrent/metastatic high-grade osteosarcomas and correlated these data with the histology of the primary resection material, with particular attention to the potential presence of any coexisting low-grade osteosarcomatous components. MDM2 and CDK4 coexpression was identified in 7 cases, and on careful histologic review 6 of them were discovered to contain foci of coexisting low-grade elements. One case was a known dedifferentiated parosteal osteosarcoma, and the remaining 5 cases were newly identified dedifferentiated osteosarcomas in which the limited low-grade components were originally unrecognized. An additional 11 cases expressed either marker alone, whereas the remaining 89 cases were negative for both markers; no resection material from these 100 cases presented with a low-grade component. MDM2/CDK4 gene amplification status, determined by quantitative polymerase chain reaction in selected cases, was largely concordant with immunoexpression. Our data suggest that MDM2 and CDK4 coexpression in high-grade osteosarcomas is sensitive and specific to those that progressed from low-grade osteosarcomas, and immunohistochemistry may help identify this dedifferentiated subgroup to facilitate accurate subclassification.
    The American journal of surgical pathology 03/2012; 36(3):423-31. · 4.06 Impact Factor
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    ABSTRACT: Chondromyxoid fibroma (CMF) of the rib is exceedingly unusual and few detailed image findings have been reported. Plain radiograph, computed tomography (CT), and magnetic resonance (MR) imaging findings and pathological aspects of a case of CMF of the right 2nd rib in a 15-year-old woman are reported, which was difficult to diagnose preoperatively. Though it is challenging to diagnose CMF preoperatively, it is important to be aware that CMF can exhibit atypical prominent exophytic features in unexpected locations such as the ribs.
    Japanese journal of radiology 12/2011; 30(1):81-5. · 0.73 Impact Factor
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    ABSTRACT: We recognized immunoreactivity for the α subset of inhibin and synaptophysin in synovial sarcomas with granular cell features. Histologic findings of 90 cases of synovial sarcoma were reviewed. Two (2.2%) of the 90 cases had granular cell features, showing sheet or nested proliferation of characteristic epithelioid cells with abundant eosinophilic and granular cytoplasm, in addition to the typical spindle cell component. The 2 cases were both female (aged 86 and 76 years). The tumors were located in the foot and the retroperitoneum and measured 3.5 and 14 cm in maximum diameter. Reverse transcriptase polymerase chain reaction analysis revealed SS18-SSX1 transcripts in both cases. SS18 gene rearrangement was detected in granular cells as well as spindle cells by chromogenic in situ hybridization. Immunohistochemistry found the granular cells to be positive for inhibin-α in both cases and for synaptophysin in 1 case, whereas spindle cells were not. Thirty-six cases (20 monophasic fibrous, 11 biphasic, and 5 poorly differentiated synovial sarcomas) were additionally examined for comparison; they showed no immunoreactivity for inhibin-α or synaptophysin. This is the first report of immunoreactivity for inhibin-α and synaptophysin in synovial sarcoma. These immunohistochemical findings might be characteristic of synovial sarcomas with granular cell features.
    Human pathology 11/2011; 43(6):850-7. · 3.03 Impact Factor
  • Journal of Orthopaedic Science 07/2011; · 0.96 Impact Factor
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    ABSTRACT: Tumor-induced osteomalacia (TIO) is an uncommon paraneoplastic syndrome rarely encountered in neurosurgical practice. We report on 2 cases of TIO caused by skull base tumors. Although the diagnosis of TIO is difficult to make and often is delayed because of the insidious nature of the symptoms, mostly systemic pain and weakness, it is curable once it is diagnosed and properly treated. Both patients presented with severe pain developing in the lower extremities and moving out to the entire body, as well as difficulty moving. They were diagnosed with TIO several years after onset. A high level of serum FGF23 was confirmed, and whole-body imaging studies demonstrated tumors in the middle and anterior cranial base, respectively. The patient with the anterior cranial base tumor had a history of hemorrhage into the frontal lobe and partial resection. En bloc resection of tumor with surrounding skull bone was performed. The histological diagnosis for both cases was phosphaturic mesenchymal tumor, mixed connective tissue variant. The level of FGF23 normalized immediately after surgery. Both patients experienced a dramatic relief of pain and recovery of muscle power. Although reports of osteomalacia caused by tumors in the neurosurgical field are extremely rare in the literature, its true incidence is unknown. We emphasize the importance of recognition of this syndrome and recommend total resection of tumors when possible.
    Neurosurgery 07/2011; 69(1):E239-44; discussion E244. · 2.53 Impact Factor
  • Journal of Orthopaedic Science 05/2011; 17(2):194-8. · 0.96 Impact Factor
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    ABSTRACT: Pathological diagnosis of synovial sarcoma is often problematic due to its broad spectrum of histology. Because synovial sarcoma consistently carries a specific chromosomal translocation, t(X;18), and its derivative chimeric gene, either SS18-SSX1 or SS18-SSX2, detecting these abnormalities by reverse transcription polymerase chain reaction or fluorescence in situ hybridization has been recognized as a powerful aid for diagnosis. Recently, chromogenic in situ hybridization, which enables simultaneous visualization of both genomic abnormality and the morphology of tumor cells, has gained attention. This study investigated the diagnostic utility of dual-color break-apart chromogenic in situ hybridization as a novel method for detecting SS18 rearrangement in synovial sarcoma. Formalin-fixed, paraffin-embedded tissue samples from 16 cases of synovial sarcoma and 10 cases of 5 other types of soft tissue sarcoma were collected. Dual-color break-apart probes were designed against the genomic region adjacent to SS18. Fluorescence and chromogenic in situ hybridization studies were performed using the same sections. In both assays, the number of signals was counted for sixty nuclei per sample. Scoring ratios (unpaired signals/paired signals) were calculated. Subsequently, SS18-SSX1 and SS18-SSX2 were examined by reverse transcription polymerase chain reaction. The results of chromogenic in situ hybridization, fluorescence in situ hybridization, and reverse transcription polymerase chain reaction were correlated. Unpaired signals were clearly observed in all the synovial sarcoma samples, which mostly indicated rearranged SS18. Synovial sarcoma and non-synovial sarcoma samples were clearly distinguished from each other by the scoring ratios. Reverse transcription polymerase chain reaction demonstrated SS18 chimeric gene transcripts in all the synovial sarcoma cases, while no fusion genes were detected in the non-synovial sarcoma cases. Taken together, unpaired signals in synovial sarcoma reflected rearranged SS18. The present chromogenic in situ hybridization-based SS18 rearrangement detection system provides a highly sensitive and specific method for the diagnosis of synovial sarcoma. Chromogenic in situ hybridization-based methods have great potential for routine use in the diagnosis of synovial sarcoma.
    Human pathology 10/2010; 41(10):1397-404. · 3.03 Impact Factor
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    ABSTRACT: Parosteal osteosarcoma and low-grade central osteosarcoma are two types of low-grade osteosarcoma that show similar clinical behaviors, histological features, and genetic background (ie, amplified sequences of 12q13-15, including MDM2 and CDK4). Low-grade osteosarcoma is often confused with benign lesions, and ancillary techniques to enhance diagnostic accuracy have been awaited. This study explores the use of MDM2 and CDK4 immunohistochemistry for the histological diagnosis of low-grade osteosarcoma. We studied 23 cases of low-grade osteosarcoma from 21 patients (parosteal osteosarcoma (n=14), low-grade central osteosarcoma (n=9)) and 40 cases of benign histological mimics (myositis ossificans (n=11), fibrous dysplasia (n=14), osteochondroma (n=6), desmoplastic fibroma (n=1), florid reactive periostitis (n=4), Nora's lesion (n=3), and turret exostosis (n=1)). Low-grade osteosarcoma labeled for MDM2 in 16 cases (70%) and for CDK4 in 20 cases (87%). All low-grade osteosarcomas expressed one or both markers (100%), with 13 cases (57%) expressing both. Staining pattern was diffuse in most cases, and the majority expressed moderate or strong intensity for either antibody. MDM2/CDK4 immunostaining was shown irrespective of low-grade osteosarcoma histological subtype. In contrast, only 1 Nora's lesion out of the 40 miscellaneous benign processes showed immunoreactivity for MDM2 or CDK4. The combination of these two markers thus shows 100% sensitivity and 97.5% specificity for the diagnosis of low-grade osteosarcoma. MDM2 and CDK4 immunostains therefore reliably distinguish low-grade osteosarcoma from benign histological mimics, and their combination may serve as a useful adjunct in this difficult differential diagnosis.
    Modern Pathology 09/2010; 23(9):1279-88. · 5.25 Impact Factor
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    ABSTRACT: Mature bone formation in well-differentiated liposarcoma and dedifferentiated liposarcoma has been described as a reactive or "metaplastic" change in most reports, and its neoplastic nature has not been widely appreciated. We herein describe 9 cases of well-differentiated/dedifferentiated liposarcoma with distinct areas of fibroosseous tissue histologically indistinguishable from low-grade osteosarcomas, that is, parosteal osteosarcoma or low-grade central osteosarcoma. The tumors affected middle-aged to elderly patients, and occurred in the retroperitoneum and deep soft tissue of the extremities without connection to the skeletal system. Grossly, all the tumors showed biphasic appearance with lipogenic and osteogenic area, the latter representing 5% to 50% of the total tumor volume. Histologically, the lipogenic component exhibited typical histology of well-differentiated liposarcoma, whereas the osteogenic area consisted of fibroosseous tissue with numerous mature neoplastic bone trabeculae largely lacking osteoblastic rimming, with intervening fascicles of spindle cell proliferation showing low nuclear grade. All samples were positive for MDM2 and/or CDK4 on immunohistochemical analysis; the antibodies stained many osteocytes, indicating that the bone is neoplastic rather than reactive. Three cases showed high-grade osteosarcomatous transformation juxtaposed to the low-grade osteosarcomatous component, reminiscent of the "dedifferentiation" phenomenon of skeletal low-grade osteosarcoma. Follow-up revealed local recurrence in 4 cases, but no distant metastases were documented. Recognition of this earlier underappreciated subtype of well-differentiated/dedifferentiated liposarcoma is important, because the fibroosseous component may seem so bland that it may be confused with benign metaplasia such as myositis ossificans, or conversely, the lipomatous component may be inconspicuous that it may be dismissed as normal fat, and such misinterpretation may potentially result in suboptimal treatment.
    The American journal of surgical pathology 09/2010; 34(9):1361-6. · 4.06 Impact Factor
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    ABSTRACT: To improve cytologic diagnostic accuracy for translocation-associated sarcomas, we explored dual-color break-apart (dc) chromogenic in situ hybridization (CISH) on liquid-based cytology (LBC) samples of 2 prototypic sarcomas: synovial sarcoma (SS) and Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET). LBC samples of 10 cases of SS and 9 cases of ES/PNET were subjected to dc-CISH using probes for the specifically rearranged genes in each tumor entity: SYT in SS and EWS in ES/PNET. Rearranged SYT was successfully detected in all SSs but not in any ES/PNETs. In contrast, EWS rearrangement was identified in all ES/PNETs but not in any SSs. These results were validated by dc-fluorescence in situ hybridization and reverse transcription-polymerase chain reaction. dc-CISH on LBC samples is a reliable modality to detect gene rearrangements in sarcomas. This system has a clear advantage over other methods, enabling simultaneous visualization of the genetic abnormality and well-preserved, nonoverlapping cytomorphologic features with clear background under bright-field microscope.
    American Journal of Clinical Pathology 08/2010; 134(2):323-31. · 2.88 Impact Factor
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    ABSTRACT: Tumor-induced osteomalacia (TIO) is a rare acquired paraneoplastic disease characterized by renal phosphate wasting and hypophosphatemia. Recently, it was reported that tumors associated with TIO produce fibroblast growth factor (FGF) 23, identified as the last member of the FGF family and of which excessive action causes several hypophosphatemic diseases whereas deficient FGF23 activity results in hyperphosphatemic tumoral calcinosis. In this case, although it was difficult to locate the associated tumor, an abnormal mass in the left maxilla was detected by imaging. The tumor was removed by partial resection of the left maxillary alveolar region. Thereafter, serum level of FGF23 rapidly decreased, hypophosphatemia improved, and the clinical symptoms greatly improved. Histopathologic diagnosis of the tumor was phosphaturic mesenchymal tumor, mixed connective tissue variant. Immunohistochemical findings confirmed that the removed tumor produced FGF23. These results indicate that development of osteomalacia in this patient was related to the maxillary tumor, which overexpressed FGF23.
    Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 03/2010; 109(3):e57-63. · 1.50 Impact Factor
  • Journal of Thoracic Oncology - J THORAC ONCOL. 01/2007; 2.
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    ABSTRACT: The distinction between ectopic hamartomatous thymoma and sarcoma is difficult, and preoperative biopsy and intraoperative histopathological examination fail to give a definitive diagnosis. It is important to recognise ectopic hamartomatous thymoma as one of the differential diagnoses of a cervical tumour.
    Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery 02/2006; 40(4):249-52. · 0.94 Impact Factor
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    ABSTRACT: We describe an 8-year-old male who had an intrapulmonary solitary fibrous tumor (SFT). SFTs of the pleura are now thought to originate from subpleural mesenchymal cells, and a pathological diagnosis is obtained by a specific marker, i.e., CD34 expression on the tumor cells. The SFT reported here is an extremely rare phenotype in two respects: it originated in a child under age 10 years, and it expanded in an intrapulmonary fashion.
    Pediatric Pulmonology 10/2005; 40(3):261-4. · 2.38 Impact Factor
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    ABSTRACT: Pigmented neurofibroma (PNF) is a rare variant of neurofibroma showing melanin production. To clarify the clinicopathologic features of PNF and to characterize melanogenesis in PNF, 12 cases of PNF were examined in comparison with schwannoma (SCH, n = 16) and neurofibroma (NF, n = 26). The PNF patients were all Japanese including 7 men and 5 women, and patient age ranged from 11 to 71 years (median, 23.5 years). They showed strong a predisposition for neurofibromatosis type 1. Their tumor size was large, and tumors arose from various sites of skin. Histologically, clusters of epithelioid, dendritic, and spindle melanin-producing cells with faint pigmentation had a tendency to locate in deep dermis and subcutis, which seems to be a characteristic pattern of melanogenesis. There was a transition between melanin-producing cells and Schwann cells. Immunohistochemical examination included known melanogenic markers, microphthalmia-associated transcription factor (MITF), which is a key regulator of melanogenesis, and 2 tyrosine kinase receptors, c-Met and c-Kit, which regulate the development of melanocytes. In PNF, melanin-producing cells were S100 (+), MITF (+), Melan-A (+), tyrosinase (+/-), HMB45 (+/-), c-Met (+), and c-Kit (-). Schwann cells were S100 (+), MITF (-), Melan-A (-), tyrosinase (-), HMB45 (-), c-Met (-), and c-Kit (-), and intermediate spindle cells were S100 (+), MITF (+), Melan-A (+), tyrosinase (-), HMB45 (-), c-Met (+), and c-Kit (-). When compared with SCH and NF, MITF was weakly expressed in a part of tumor cells of SCH, whereas no definite staining was found in NF. c-Met expression was very weak in a scattered manner in SCH (10/15 cases) and NF (10/26 cases). These results suggest that PNF is a unique tumor that shows differentiation toward mature melanin production, but ability of melanin synthesis seems to be impaired. There may be a close relationship between up-regulated MITF and c-Met and the peculiar melanogenic nature of PNF, and both of these are useful diagnostic tools for distinguishing PNFs with less melanin production from NFs.
    Human Pathlogy 09/2005; 36(8):871-7. · 2.84 Impact Factor
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    ABSTRACT: A case of repeated obstructive jaundice and acute pancreatitis caused by mucus plug produced by metastatic liver tumor is reported. A 74-year-old woman, who had a past history of curative resection of mucinous rectal cancer, showed repeated obstructive jaundice and acute pancreatitis during the follow-up period. Neither computed tomographic scan nor abdominal ultrasound could detect the recurrent lesion, however, cholangioscopy detected mucin and tumor projection into the left hepatic duct. Since the biopsy specimen of the tumor revealed adenocarcinoma, left hepatectomy was performed. The tumor was mucinous adenocarcinoma having the same histology as the primary rectal cancer, with partly mucosal replacement and formation of intraluminal mucus plaque. This case indicates that repeated obstructive jaundice and acute pancreatitis should be considered one of the manifestations of liver metastasis of mucinous cancer.
    Hepato-gastroenterology 01/2005; 52(61):220-2. · 0.77 Impact Factor
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    ABSTRACT: A 46-year-old Japanese female with advanced gastric cancer with positive peritoneal cytology and who was refractory to methotrexate plus 5-FU sequential chemotherapy received low-dose, fractional irinotecan hydrochloride (CPT-11) in combination with cisplatin. This regimen could be repeated biweekly on an outpatient basis and was well tolerated. After 8 cycles of administration, a negative change in peritoneal cytology subsequently enabled a total gastrectomy, splenectomy, and cholecystectomy with a D3 lymph node dissection. The rationale for a low-dose, fractional administration of CPT-11 in combination with cisplatin is the synergistic antitumor activity obtained through the ability of SN-38 to potentiate cisplatin-induced cytotoxicity, as well as the increased therapeutic efficacy of a protracted CPT-11 administration over more intense treatment schedules. As far as we are aware, this case report demonstrates for the first time that a low-dose, fractional administration of CPT-11 with cisplatin can successfully produce a negative change in peritoneal lavage cytology, and potentiates a R0 resection in a 5-FU resistant advanced gastric cancer patient. This suggests that this combination could be an effective regimen for potentially disseminated, 5-FU resistant patients.
    Gan to kagaku ryoho. Cancer & chemotherapy 07/2004; 31(6):929-32.

Publication Stats

281 Citations
84.98 Total Impact Points


  • 2012–2014
    • Tokyo Metropolitan Cancer and Infectious Diseases Center
      Edo, Tōkyō, Japan
  • 2010
    • Teikyo University Hospital
      Edo, Tōkyō, Japan
    • Teikyo University
      • Department of Medicine
      Edo, Tōkyō, Japan
  • 2005
    • Showa General Hospital
      Edo, Tōkyō, Japan
  • 2002–2005
    • Tokyo Medical University
      • Department of Pathology
      Edo, Tōkyō, Japan
  • 1998–2004
    • The University of Tokyo
      • • Department of Surgical Sciences
      • • Department of Pathology
      Tokyo, Tokyo-to, Japan
  • 2000
    • University of Occupational and Environmental Health
      • Department of Pathology and Oncology
      Kitakyūshū, Fukuoka, Japan