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Dive into the research topics where Masashi Sugasawa is active.

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Featured researches published by Masashi Sugasawa.


Cancer | 2002

Results of Multimodality Therapy for Squamous Cell Carcinoma of Maxillary Sinus

Ken-ichi Nibu; Masashi Sugasawa; Masao Asai; Keiichi Ichimura; Masato Mochiki; Atsuro Terahara; Nobutaka Kawahara; Hirotaka Asato

A wide variety of modalities, including surgery, radiation therapy, and chemotherapy, alone or in combination, have been used for the treatment of squamous cell carcinoma (SCC) of the maxillary sinus to obtain better local control and maintain functions. However, there is still much controversy with regard to the optimum treatment.


Neurosurgery | 1998

Complications of craniofacial surgery for tumors involving the anterior cranial base.

Ken-ichi Nibu; Tsutomu Sasaki; Nobutaka Kawahara; Masashi Sugasawa; Takashi Nakatsuka; Yamada A

OBJECTIVE To evaluate the risk factors for postoperative complications among patients undergoing craniofacial resection for the treatment of anterior cranial base tumors, a retrospective analysis of patients treated in University of Tokyo Hospital between September 1987 and November 1996 was conducted. METHODS Twenty-nine patients underwent 33 craniofacial resections for tumors involving the anterior cranial base. Twenty-three of the 29 patients had malignant tumors and 6 patients had benign tumors. Anterior craniofacial resection was performed using a combination of intracranial and extracranial approaches. Radiotherapy and neoadjuvant chemotherapy were administrated to some patients. RESULTS Severe intracranial infections were more common among patients who underwent partial frontal lobectomies (P < 0.03). These infections occurred only in patients who had been treated previously with a craniotomy (P < 0.02) and a total radiation dose of > or =60 Gy (P = 0.06). Neither management of the extracranial structures nor methods of reconstruction of the cranial base showed significant correlation with major postoperative complications. CONCLUSION Compared with previous reports, craniofacial resection has become a relatively safe and effective procedure for the treatment of tumors involving the anterior cranial base. However, additional care should be taken with patients who have experienced a previous craniotomy, frontal lobe involvement, or radiotherapy with a total dose of > or =60 Gy.


Otolaryngology-Head and Neck Surgery | 2002

Stomal recurrence after total laryngectomy for squamous cell carcinoma of the larynx.

Yutaka Imauchi; Ken Ito; Esao Takasago; Ken-ichi Nibu; Masashi Sugasawa; Keiichi Ichimura

OBJECTIVE : Stomal recurrence after total laryngectomy is one of the most serious issues in the management of laryngeal carcinoma. The management of stomal recurrence, including chemotherapy, radiotherapy, and surgery, has been reported as unsatisfactory. STUDY DESIGN AND SETTING : From 1985 to 1995, 69 patients underwent total laryngectomy for the treatment of laryngeal cancer at the University of Tokyo Hospital. To identify the risk factors for stomal recurrence, we analyzed these patients according to various clinicopathological factors. RESULTS : Stomal recurrence developed in 6 of 69 patients who underwent total laryngectomy for laryngeal carcinoma. Statistical analysis reveals that primary site, preoperative tracheotomy, and paratracheal lymph node metastasis are significant risk factors for stomal recurrence. CONCLUSION : Intensive follow-up should be performed for patients with glottic carcinoma who had preoperative tracheotomy, paratracheal lymph node metastasis, or both to detect stomal recurrence at an early stage.


Oncology | 2014

Prevalence of Human Papillomavirus in Oropharyngeal Cancer: A Multicenter Study in Japan

Takanori Hama; Yutaka Tokumaru; Masato Fujii; Katsunari Yane; Kenji Okami; Kengo Kato; Muneyuki Masuda; Hiroyuki Mineta; Torahiko Nakashima; Masashi Sugasawa; Noriyuki Sakihama; Tomokazu Yoshizaki; Toyoyuki Hanazawa; Hisayuki Kato; Shigeru Hirano; Yorihisa Imanishi; Yuichirou Kuratomi; Naoki Otsuki; Ichiro Ota; Taro Sugimoto; Shinsuke Suzuki

Background: The incidence rates of oropharyngeal squamous cell carcinoma (OPSCC) have risen steadily in the USA and in northern Europe. These increases are thought to be a consequence of persistent infection with high-risk human papillomavirus (HPV) in OPSCC patients. HPV is an emerging etiologic factor in OPSCC. In Japan, the incidence of OPSCC has significantly increased over the last three decades. However, the population of HPV-positive OPSCC patients is currently unknown. We examined the nationwide trends with regard to HPV incidence in OPSCC patients at 21 specific sites, and examined the relationship between the presence of HPV and survival in OPSCC patients in Japan. Methods: Tumor samples were obtained from patients with OPSCC prior to treatment, and HPV infection was investigated by polymerase chain reaction (PCR). Hybrid Capture 2 (HC2) was also adopted for swab examination on the surface of fresh tumors. Results: HPV was detected by PCR in 79 (50.3%) out of 157 OPSCC patients. The clinical features of HPV-positive OPSCC were low differentiation, a tendency to involve the lateral wall, and high nodal staging. The sensitivity and specificity of HC2 were 93.7 and 96.2%, respectively, indicating its utility as a screening test. HPV-positive patients had significantly better overall survival and disease-free survival than HPV-negative patients.


European Archives of Oto-rhino-laryngology | 1993

An Electrocochleographic Study of Acute Low-Tone Sensorineural Hearing Loss

Tatsuya Yamasoba; Masashi Sugasawa; Shigeru Kikuchi; Masato Yagi; Takehiko Harada

SummaryTwenty-four patients with acute low-tone sensorineural hearing loss (ALHL) were examined using electrocochleography. The negative summating potential (SP) amplitude and the summating potential/action potential (AP) ratio were significantly greater in the ALHL patients than in normals. The SP/AP ratio was smaller in the ALHL patients than in patients with known Menieres disease and moderate hearing loss, although the SP amplitude was somewhat greater in the former. An abnormal increase in the SP amplitude following click stimuli was found in 54% of the ALHL patients, while the SP/AP ratio was increased abnormally in 63% of these patients. These findings suggest that the pathophysiology of ALHL may be similar to that for endolymphatic hydrops.


Acta Neurochirurgica | 1998

Dumbbell Type Jugular Foramen Meningioma Extending Both into the Posterior Cranial Fossa and into the Parapharyngeal Space: Report of 2 Cases with Vascular Reconstruction

Nobutaka Kawahara; Tsutomu Sasaki; Ken-ichi Nibu; Masashi Sugasawa; Keiichi Ichimura; Takashi Nakatsuka; Atsushi Yamada; Takaaki Kirino

Summary Two cases with huge dumbbell type jugular foramen meningioma with extension into the parapharyngeal space are reported. A well co-ordinated surgical strategy for total resection to this high risk tumour with neurosurgeons, otolaryngologists and plastic surgeons is mandatory to minimise operative complications. Both of our patients presented with a cervical mass and lower cranial nerve palsies, and had huge dumbbell type masses extending from the posterior cranial fossa through the jugular foramen to the parapharyngeal space, encasing the cervical internal carotid artery. Gross total resection of the tumours was successfully achieved by basically a 2-stage operation. In the first stage, posterior fossa tumours were removed by the transjugular approach, combined with the petrosal approach in one case. In the second stage, cervical tumours were removed along with the cervical carotid artery by the transcervical and/or transmandibular approach, followed by vascular reconstruction from the ipsilateral carotid artery to the middle cerebral artery using saphenous vein graft. From these experiences, we recommend this 2-stage operation for large dumbbell type meningiomas extending to the infratemporal/parapharyngeal space. The intracranial tumour is removed at the first operation. The extracranial portion is resected at the second, and if necessary, the involved cervical carotid artery is resected and simultaneous revascularisation using saphenous vein graft is performed with a vascularised free muscle graft. This strategy could maximise the functional preservation on the one hand, and minimise the surgical risk, such as postoperative infection, on the other.


Annals of Diagnostic Pathology | 2009

Ghost cell odontogenic carcinoma arising in calcifying odontogenic cyst.

Utaroh Motosugi; Ikuko Ogawa; Tetsuya Yoda; Takahiro Abe; Masashi Sugasawa; Shin-ichi Murata; Masanori Yasuda; Takaki Sakurai; Yoshihiko Shimizu; Michio Shimizu

A case of exceptionally rare odontogenic malignant tumor, called ghost cell odontogenic carcinoma, is described. The tumor was considered to be derived from calcifying odontogenic cyst, which had been resected 5 years before. In the present resected specimen, cellular atypia, mitotic activity, Ki-67 labeling index, and p53 positivity were all increased in comparison with the initially resected specimen. This is a valuable case in which malignant transformation from calcifying odontogenic cyst to ghost cell odontogenic carcinoma was proven by the histopathologic and immunohistochemical findings. Pathologists should be aware of this rare entity.


Operations Research Letters | 1994

Occult Follicular Carcinoma Metastasizing to the Sinonasal Tract

Tatsuya Yamasoba; Shigeru Kikuchi; Masashi Sugasawa; Ryuzaburo Higo; Tomio Sasaki

We report a 34-year-old woman with a clinically occult primary carcinoma of the thyroid metastasizing to the sinonasal tract. The metastasis showed intensive vascularization and involved the nose, the maxillary, ethmoid and sphenoid sinuses, extending to the intracranial cavity. After embolization, the lesion was removed and histopathologically diagnosed as follicular carcinoma of the thyroid. A subsequent total thyroidectomy revealed an 8-mm primary lesion within the left lobe. Thyroid metastases, although rare, need to be considered in the differential diagnosis of hypervascular tumors in the sinonasal tract.


Otolaryngology-Head and Neck Surgery | 2006

Analysis of Prognostic Factors of Nasopharyngeal Carcinoma: Impact of in Situ Hybridization for Epstein-Barr Virus Encoded Small RNA 1

Kazunari Nakao; Masato Mochiki; Ken-ichi Nibu; Masashi Sugasawa; Hiroshi Uozaki

OBJECTIVES: To evaluate the impact of clinical, histopathological, and molecular biological parameters on the prognosis of nasopharyngeal carcinoma (NPC). STUDY DESIGN AND SETTING: The clinical records of 48 patients with a diagnosis of NPC were retrospectively reviewed. In situ hybridization for Epstein-Barr virus encoded small RNA 1 (EBER-ISH) was applied for 30 paraffin-embedded specimens available. Prognostic factors of NPC were meticulously analyzed. RESULTS: The EBER-ISH signal was shown to be highly significant as a favorable prognostic factor (P = 0.007). Although EBV was more commonly associated with Type III NPC, EBER-ISH-positive Type I-II NPC had also significantly better survival rate than EBER-ISH-negative Type I-II NPC (P = 0.036). CONCLUSIONS: In addition to the WHO histopathological grade, the 1997 UICC staging, nodal status, and distant metastasis at presentation, the EBER-ISH signal was shown to be significant as a prognostic factor. SIGNIFICANCE: This is the first report to describe the EBER-ISH as an independent prognostic factor of NPC regardless of histopathology.


American Journal of Otolaryngology | 2012

Quantitative diffusion-weighted magnetic resonance imaging as a powerful adjunct to fine needle aspiration cytology for assessment of thyroid nodules.

Mitsuhiko Nakahira; Naoko Saito; Shin-ichi Murata; Masashi Sugasawa; Yumiko Shimamura; Kei Morita; Fumihiko Takajyo; Go Omura; Satoko Matsumura

OBJECTIVES The purpose of this study was to assess the value of the apparent diffusion coefficient (ADC) in the differential diagnosis between benign and malignant thyroid nodules, particularly those found to have indeterminate cytology with fine needle aspiration (FNA). METHODS Thirty-eight patients with 42 thyroid nodules underwent neck magnetic resonance imaging consisting of T1-, T2-, and diffusion-weighted imaging. The final diagnosis of all nodules was confirmed by surgery, revealing 23 with benign and 19 with malignant lesions. Preoperative FNA cytology was performed in 38 of 42 nodules, including 15 of indeterminate cytology. The mean ADC values in benign and malignant groups were compared. RESULTS There was a significant difference between mean ADC values in benign and malignant nodules and between mean ADC in benign and malignant nodules of indeterminate cytology. A cutoff value for malignant nodules of 1.60 × 10(-3) mm(2)/s yielded sensitivity, specificity, and accuracy of 94.73%, 82.60%, and 88.09%, respectively. CONCLUSION The present study revealed that ADC measurements could potentially quantitatively differentiate between benign and malignant thyroid nodules, even those of indeterminate cytology. We propose that diffusion-weighted imaging evaluation should be used for the assessment of thyroid nodules in addition to FNA cytology.

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Kiyomi Kuba

Saitama Medical University

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Takahiro Asakage

Tokyo Medical and Dental University

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Kazuhiko Minami

Saitama Medical University

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Kimitaka Kaga

International University of Health and Welfare

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