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Dive into the research topics where Shinichiro Koyama is active.

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Featured researches published by Shinichiro Koyama.


European Journal of Radiology | 2015

Multiple, thin-walled cysts are one of the HRCT features of airspace enlargement with fibrosis

Yasutaka Watanabe; Yoshinori Kawabata; Tetsu Kanauchi; Eishin Hoshi; Kazuyoshi Kurashima; Shinichiro Koyama; Thomas V. Colby

PURPOSE Airspace enlargement with fibrosis (AEF) has been identified pathologically as a smoking related change. We sought to identify the HRCT findings of AEF and search for distinguishing features from honeycombing. MATERIALS AND METHODS 50 patients (47 males; mean age 69) were evaluated. All had undergone lobectomy for lung cancer and had confirmed AEF and/or usual interstitial pneumonia (UIP) by pathological evaluation. HRCT findings were first evaluated preresection for resected lobes, and then correlated with the subsequent pathological findings in the resection specimens. Three groups were devised: one with AEF alone to determine the HRCT findings of AEF, a second with AEF and UIP and third with UIP alone. HRCT features of AEF and honeycombing were compared. RESULTS There were 11 patients (10 male; mean age 69) with AEF alone, 24 patients (22 male; mean age 69) with AEF and UIP, and 15 patients (15 male; mean age 68) with UIP alone. The HRCT on the AEF alone showed subpleural (but not abutting the pleura) multiple thin-walled cysts (MTWCs) in 7 and reticular opacities in 3. The HRCT in AEF and UIP showed MTWCs in 10, reticular opacities in 17; and honeycombing in 5. Among these 35 patients with the pathological finding of AEF (with or without UIP), 17 showed MTWCs. The maximum cyst wall thickness of MTWCs (mean 0.81 mm) was significantly thinner than that of honeycombing (mean 1.56 mm). MTWCs did not locate in lung base and was distant from the pleura. HRCT findings correlated with gross findings on both cysts and honeycombing. No MTWCs were seen in the 15 patients with UIP, 8 of 15 had honeycombing on CT. CONCLUSIONS We confirmed that HRCT features of AEF were MTWCs and/or reticular opacities. MTWCs might be distinguished from those of honeycomb change. While we prefer the term MTWCs, these sorts of changes have probably been confused with/interpreted as honeycombing and/or empysema in the past.


The Japanese Journal of Thoracic and Cardiovascular Surgery | 2010

Thymic clear cell carcinoma

Tomoyuki Nakano; Shunsuke Endo; Hiroyoshi Tsubochi; Mitsuhiro Nokubi; Yasutaka Watanabe; Shinichiro Koyama

We report a 42-year-old man with a rare thymic clear cell carcinoma. Marked nodal metastases involved right hilar, mediastinal, and left supraclavicular regions. Complete resection including thymothymectomy, cervicomediastinal nodal dissection, and right upper lobectomy with hilar lymphadenectomy was successful. Postoperative chemoradiation therapy was uneventful. The patient had no recurrence or metastasis until brain metastasis occurred 1 year after surgery.


Chemotherapy | 2017

Distinct Benefit of Overall Survival between Patients with Non-Small-Cell Lung Cancer Harboring EGFR Exon 19 Deletion and Exon 21 L858R Substitution

Nobuyuki Koyama; Yasutaka Watanabe; Yuki Iwai; Rumi Kawamura; Chihiro Miwa; Yoshiaki Nagai; Koichi Hagiwara; Shinichiro Koyama

Background: Exon 19 deletion (Del19) and exon 21 L858R substitution (L858R), which account for 90% of epidermal growth factor receptor (EGFR) mutations as common mutations, are associated with favorable outcomes with EGFR-tyrosine kinase inhibitors (TKIs) compared with other uncommon EGFR mutations in non-small-cell lung cancer (NSCLC). However, whether there are differences in overall survival (OS) between patients with these common EGFR mutations remains controversial. Methods: The subjects studied were 74 NSCLC patients with common EGFR mutations treated with gefitinib or erlotinib. Using univariate and multivariate analyses, we retrospectively compared the clinicopahological characteristics of patients harboring Del19 with those harboring L858R. Results: Compared with patients harboring L858R, EGFR-TKIs provided a significant OS benefit in patients harboring Del19 (p = 0.024), as well as favorable therapeutic responses (p = 0.045) and progression-free survival (PFS) benefits (p = 0.031). In multivariate analyses, Del19 was independently associated with PFS (p = 0.029) and OS (p = 0.009), whereas no parameters other than pleural dissemination at the initial treatment were associated with EGFR mutation types. Conclusion: Del19 and L858R have distinct prognostic implications and may require individual therapeutic strategies.


Internal Medicine | 2018

Advanced Lung Adenocarcinoma with Nivolumab-associated Dermatomyositis

Fumiaki Kudo; Yasutaka Watanabe; Yuki Iwai; Chihiro Miwa; Yoshiaki Nagai; Hiromitsu Ota; Hiroki Yabe; Toshio Demitsu; Koichi Hagiwara; Nobuyuki Koyama; Shinichiro Koyama

We herein report a 42-year-old man with advanced lung adenocarcinoma and nivolumab-associated dermatomyositis. Nivolumab, an anticancer drug that is classified as an immune checkpoint inhibitor, often induces immune-related adverse events (irAEs). However, there have so far been no reports regarding nivolumab-associated dermatomyositis. This patient was diagnosed with dermatomyositis due to the presence of proximal muscle weakness with abnormal electromyography and magnetic resonance imaging findings; skin lesions, such as heliotrope rash, shawl sign, and periungual erythema; and an elevated serum aldolase level after nivolumab administration. It is important to consider drug-associated dermatomyositis in the differential diagnosis of patients presenting with skin lesions and muscle weakness after nivolumab treatment.


The Japanese Journal of Thoracic and Cardiovascular Surgery | 2011

Extended sleeve lobectomy for interlobar lymph node metastasis invading the bronchus from peripheral lung cancer

Hiroyoshi Tsubochi; Yoshihiko Kanai; Kenji Tezuka; Yasutaka Watanabe; Shinichiro Koyama; Tomoyuki Nakano; Katsuhiko Isogami; Shunsuke Endo

Although extended sleeve lobectomy has been used as an alternative to pneumonectomy for the treatment of centrally located lung cancer, the validity of this surgical procedure is unclear in patients with peripheral lung cancer with interlobar lymph node metastasis invading the bronchus. We herein report four patients with peripheral lung cancer in the left lower lobe who underwent extended sleeve lobectomy consequent to interlobar lymph node metastasis. The tumor and metastasized lymph node was extirpated en bloc with division of the main bronchus and upper division bronchus, and those bronchi were anastomosed using the telescope method. All patients were doing well without recurrence. Extended sleeve lobectomy may be applicable to patients with peripheral lung cancer with interlobar lymph node metastasis invading the bronchus to avoid pneumonectomy.


The Japanese Journal of Thoracic and Cardiovascular Surgery | 2009

End-stage localized bronchiectasis mimicking a hemangioma

Sayaka Otani; Shunsuke Endo; Hiroyoshi Tsubochi; Mitsuhiro Nokubi; Shinichiro Koyama

We report a case of localized bronchiectasis mimicking a hemangioma demonstrated on enhanced chest computed tomography. Left lower lobectomy following selective bronchial arterial embolization was successful. Pathology evaluation showed markedly dilated bronchial arteries along a dilated bronchus displacing the lateral and posterior basal segments.


Respiratory medicine case reports | 2017

A young immunocompetent patient with spontaneous Aspergillus empyema who developed severe eosinophilia

Fumiaki Kudo; Hiromitsu Ohta; Yoshiaki Nagai; Kentaro Minegishi; Shinichiro Koyama

Aspergillus empyema is usually reported as a complication of surgical procedures, and spontaneous cases are quite rare. Here, we describe the case of a 16-year-old man who suddenly developed dyspnea despite previously being healthy. Chest computed tomography showed multiple mass-containing cavity lesions, pneumothorax, and pleural effusion in the left thorax. Within 2 weeks, Aspergillus fumigatus grew from his pleural effusion, thus he was diagnosed with Aspergillus empyema. He also developed severe eosinophilia after admission, and was treated with anti-fungal drugs. Although there are many factors that can cause eosinophilia, we suspect that infection with Aspergillus fumigatus was the major cause of the eosinophilia in this patient. The lack of bronchial symptoms and lesions were not consistent with a diagnosis of allergic bronchopulmonary aspergillosis. As far as we know, this is the first case of spontaneous Aspergillus empyema resulting in severe eosinophilia.


Respiratory Medicine | 2017

A clinicopathological study of surgically resected lung cancer in patients with usual interstitial pneumonia

Yasutaka Watanabe; Yoshinori Kawabata; Nobuyuki Koyama; Tomohiko Ikeya; Eishin Hoshi; Noboru Takayanagi; Shinichiro Koyama

BACKGROUND The clinicopathological characteristics of lung cancer with concomitant usual interstitial pneumonia (UIP) are insufficiently understood. This study aimed to elucidate a characteristic pathological feature of lung cancer that develops in patients with UIP, with a focus on the location of its onset. METHODS We reviewed surgically obtained specimens, including 547 tumors from 526 patients who underwent lobectomy for lung cancer. Surveyed patients were classified into three groups: patients with UIP (UIP group), patients with lung pathology other than UIP (non-UIP group), and patients without any associated lung pathology (normal group). The histology as well as the lobe and location of the onset of lung cancer were compared among these groups. The peripheral location was subdivided into subpleural, inner and tumor involved centrally secondary to extension. RESULTS The UIP group comprised 82 patients (male, 71 [87%]; mean age, 71 years; smoking rate, 94%), the non-UIP group comprised 334 patients (male, 267 [80%]; mean age, 69 years; smoking rate, 81%), and the normal group comprised 110 patients (male, 33 [30%]; mean age, 63; smoking rate, 29%). No statistical differences were noted in sex, mean age, or smoking index between the UIP and non-UIP groups. Compared with the non-UIP group, the frequency of squamous cell carcinoma (63% vs. 32%), lower lobe origin (76% vs. 32%), and subpleural location (24% vs. 5%) were significantly higher in the UIP group. CONCLUSIONS Lung cancers in patients with UIP show a predilection for the subpleural region, where UIP is also thought to originate.


Journal of General and Family Medicine | 2017

Early‐stage diffuse panbronchiolitis in a young patient confirmed by video‐assisted lung biopsy: A case report

Yasutaka Watanabe; Yoshinori Kawabata; Yuki Iwai; Fumiaki Kudo; Rumi Kawamura; Chihiro Miwa; Yoshiaki Nagai; Shinichiro Koyama

A 29‐year‐old man presented with sputum and cough, which were pointed out by his neighbors. A high‐resolution chest computed tomography scan showed well‐defined multiple centrilobular nodules and a tree‐in‐bud pattern. Chest auscultation revealed coarse crackles. He did not report any nasal sinus symptoms. We subsequently performed a video‐assisted lung biopsy; the specimen confirmed diffuse panbronchiolitis. Subsequently, sinusitis was confirmed by an otolaryngologist. His symptoms gradually improved following treatment with erythromycin. We report a case of early‐stage diffuse panbronchiolitis in a young patient, with multiple intralobular nodules, no bronchiectasis, and a good clinical course.


The Japanese Journal of Thoracic and Cardiovascular Surgery | 2008

Large-cell neuroendocrine carcinoma without immunohistological positivity or serum elevation of CEA until relapse

Yasutaka Watanabe; Shunsuke Endo; Hiroyoshi Tsubochi; Mitsuhiro Nokubi; Shinichiro Koyama; Yasunori Sohara

We herein report a case of large cell neuroendocrine carcinoma (LCNEC) originating in the right lung upper lobe and showing unique features at relapse in the right middle lobe. The relapsed tumor pathology included a carcinoembryonic antigen (CEA)-positive mantle component and a CEA-negative core area. The latter showed the same pathological picture as the original tumor, both histologically and immunohistochemically. The serum CEA concentration did not increase until the tumor relapsed, and it fell to within the normal range after resection of the relapsed tumor. Rarely, a newly elevated tumor marker suggests relapse, even in resected cases with a negative immunohistochemical study for the marker.

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Chihiro Miwa

Jichi Medical University

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Shunsuke Endo

Jichi Medical University

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Yoshiaki Nagai

Saitama Medical University

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Yuki Iwai

Jichi Medical University

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