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Dive into the research topics where Masahiro Kitada is active.

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Featured researches published by Masahiro Kitada.


Breast Cancer | 2003

Granulomatous Mastitis Diagnosed by Core-Needle Biopsy and Successfully Treated with Corticosteroid Therapy : A Case Report

Satoshi Hirata; Takashige Saito; Kaori Kiyanagi; Masahiro Kitada; Kosuke Yamazaki; Tadahiro Sasajima; Yoshinobu Ohsaki; Naoyuki Miyokawa

A 46-year-old woman presented to our hospital with a rapidly growing lump in her right breast. Fineneedle aspiration (FNA) cytology and core needle biopsy of the mass revealed many epithelioid cells admixed with multinucleated Langhans-type giant cells, neutrophils, lymphocytes, and stromal cells, leading to a diagnosis of granulomatous mastitis. Mammography and ultrasonography provided little information for differentiating between granulomatous mastitis and carcinoma. This patient was successfully treated with low dose and short period of corticosteroid therapy.


Journal of Translational Medicine | 2011

Six-transmembrane epithelial antigen of the prostate and enhancer of zeste homolog 2 as immunotherapeutic targets for lung cancer

Satoshi Hayashi; Takumi Kumai; Yoshiya Matsuda; Naoko Aoki; Keisuke Sato; Shoji Kimura; Masahiro Kitada; Masatoshi Tateno; Esteban Celis; Hiroya Kobayashi

BackgroundT-cell based immunotherapy for lung cancer (LC) could be a promising and novel therapeutic approach. Six-transmembrane epithelial antigen of the prostate (STEAP) and the polycomb group protein enhancer of zeste homolog 2 (EZH2) are highly expressed in LC and since the expression of molecules in normal tissue is significantly lower as compared to tumor cells, these proteins are considered as potential tumor-associated antigens (TAAs) for developing T-cell based immunotherapy.MethodsWe assessed the capacity of predicted CD4 T-cell epitopes from STEAP and EZH2 to induce anti-tumor immune responses to LC cell lines.ResultsOut of several predicted epitopes, two synthetic peptides, STEAP281-296 and EZH295-109, were effective in inducing CD4 T-cell responses that were restricted by HLA-DR1, DR15, or DR53 molecules, indicating that the peptides function as promiscuous T-cell epitopes. Moreover, STEAP281-296 and EZH295-109-reactive T-cells could directly recognize STEAP or EZH2 expressing LC cells in an HLA-DR restricted manner. In addition, some STEAP-reactive T-cells responded to STEAP+ tumor cell lysates presented by autologous dendric cells. Most significantly, both of these peptides were capable of stimulating in vitro T-cell responses in patients with LC.ConclusionsPeptides STEAP281-296 and EZH295-109 function as strong CD4 T-cell epitopes that can elicit effective anti-tumor T-cell responses against STEAP or EZH2 expressing LC. These observations may facilitate the translation of T-cell based immunotherapy into the clinic for the treatment of LC.


Journal of Cardiothoracic Surgery | 2013

IgG4-related lung disease showing high standardized uptake values on FDG-PET: report of two cases

Masahiro Kitada; Yoshinari Matuda; Satoshi Hayashi; Kei Ishibashi; Kensuke Oikawa; Naoyuki Miyokawa; Yoshinobu Ohsaki

Immunoglobulin G4 (IgG4)-related lung disease is a disease in which IgG4-positive plasma cells and lymphocytes infiltrate lung tissues along with immunohistochemically evident fibrous interstitial proliferation in the background, in addition to hyper-IgG4 disease. The diagnosis of this disease can be difficult. Here, we report 2 cases with IgG4-related lung disease that was difficult to differentiate from malignant tumors because both cases had pulmonary lesions showing high standardized uptake values (SUV) on positron emission tomography (PET). Case 1: A 75-year-old man under treatment for autoimmune pancreatitis and diabetes mellitus was noted to have multiple nodular opacities in both lungs and a mass density in the right paravertebral region on computed tomography (CT). As high SUVmax was noted for both lesions on exploration by fluorodeoxyglucose (FDG)-PET/CT, an advanced malignant tumor was diagnosed and a video-assisted thoracoscopic (VATS) biopsy was performed and diagnosed IgG4-related lung disease. Case 2: A 48-year-old woman consulted our clinic with a chief complaint of bloody sputum. Chest CT revealed a mass density with 12-, 13-, and 16-mm spiculations in the S2 segment of the right upper lobe and irregular thickening of the pleura including the paravertebral region. The lesion was a mass showing high SUV in the S2 segment on FDG-PET. Malignancy was suspected from the imaging findings, and a VATS biopsy was performed and diagnosed IgG4-related lung disease. Actively undertaking VATS biopsy in cases with this disease is valuable for making the differential diagnosis between malignant tumors and IgG4-related lung disease, since the diagnosis can be difficult in some patients showing high SUV.


World Journal of Surgical Oncology | 2013

Esophageal schwannoma: a case report.

Masahiro Kitada; Yoshinari Matsuda; Satoshi Hayashi; Kei Ishibashi; Kensuke Oikawa; Naoyuki Miyokawa

Most tumorous lesions of the esophagus are esophageal cancers. Benign primary tumors of the esophagus are uncommon, and account for approximately 2% of all esophageal tumors. More than 80% of benign esophageal tumors are leiomyomas, with schwannomas being rare. A 55-year-old woman visited our internal medicine department with complaints of palpitations and discomfort during swallowing. A chest computed tomography scan showed a lobulated tumor (75 × 57 × 80 mm) in the upper to middle mediastinum, with homogenous inner opacity, compressing the esophagus. Upper gastrointestinal endoscopy revealed a smooth-surfaced elevated lesion covered with normal mucosa, and a schwannoma was diagnosed based on the biopsy result. The tumor was large. It was thus considered to be difficult to repair the esophagus by direct anastomosis after tumor resection. Therefore, subtotal esophagectomy and esophagogastrostomy in the right thorax were performed. Histopathological examination revealed spindle-shaped cells in a fasciculated and disarrayed architecture and nuclei in a palisading pattern. Immunohistochemical studies revealed S100 protein positivity and the absence of staining for α smooth muscle actin (αSMA), CD34 and CD117, thereby establishing the diagnosis of benign schwannoma. Her postoperative course was uneventful and there has been no evidence of recurrence to date.


Journal of Cardiothoracic Surgery | 2011

Mucoepidermoid carcinoma of the lung: a case report

Masahiro Kitada; Yoshinari Matsuda; Kazuhiro Sato; Satoshi Hayashi; Kei Ishibashi; Naoyuki Miyokawa; Tadahiro Sasajima

Mucoepidermoid carcinoma of the lung (MEC) is a tumor of low malignant potential of bronchial gland origin. MEC and adenoid cystic carcinoma are both considered to be salivary gland-type neoplasms. MECs are comparatively rare with an incidence of all lung cancers. We recently encountered a case of this type of lung cancer. A 60-year-old man was found to have an abnormal shadow in the left lower lung field on a regular check-up for lung cancer at his company. Chest radiography and CT revealed a mass shadow measuring 30 mm in diameter in the left lower lung field. Bronchoscopy revealed a protuberant tumor in the S9 bronchus, leading to a diagnosis of low-grade MEC by transbronchial lung biopsy. He underwent left lower lobe resection and mediastinal lymph node dissection using VATS. Tumor cells had a scattering of mucus-producing epithelial components in papillary growth of stratified squamous epithelia with anisokaryosis and minimal pleomorphism, indicating a diagnosis of MEC. Because the postoperative course was good and the tumor was low-grade, no adjuvant treatment was administered. The patient has had no signs of tumor recurrence for 9 months, to date, since resection of the tumor


World Journal of Surgical Oncology | 2010

Adenoid cystic carcinoma of the peripheral lung : a case report

Masahiro Kitada; Keisuke Ozawa; Kazuhiro Sato; Satoshi Hayashi; Yoshihiko Tokusashi; Naoyuki Miyokawa; Tadahiro Sasajima

Adenoid cystic carcinoma of the peripheral lung is a rare entity. We recently encountered a patient with adenoid cystic carcinoma. A 75-year-old woman showed a nodular lesion with 10 mm in diameter in the right upper lung field on chest radiography. The diagnosis was unclear, but lung cancer could not be ruled out. Thoracoscopic biopsy was performed, and intraoperative pathological diagnosis revealed the carcinoma of the lung. We enforced upper lobectomy and mediastinal lymph node dissection to the patient. Histopathological examination revealed adenoid cystic carcinoma with a characteristic cribriform structure. Immunohistochemical examination revealed that the tumor cells were positive for thyroid transcription factor 1 (TTF-1), this tumor was diagnosed primary ACC of the lung.


World Journal of Surgical Oncology | 2011

Ectopic thymoma presenting as a giant intrathoracic tumor: A case report

Masahiro Kitada; Kazuhiro Sato; Yoshinari Matsuda; Satoshi Hayashi; Yoshihiko Tokusashi; Naoyuki Miyokawa; Tadahiro Sasajima

Ectopic thymoma rarely presents as an intrathoracic tumor. We report a case of ectopic thymoma presenting as a giant right intrathoracic tumor that was treated with resection. The patient was a 50-year-old Japanese woman who presented with the chief complaint of chest pain. Detailed examination revealed a solid tumor measuring 15 × 10 × 8 cm in diameter, with a clear border. The Imaging findings suggested a solitary fibrous tumor, and surgery was performed. At surgery, the tumor was found to beadherent to the diaphragm, mediastinal pleura, and lower lobe of the lung, although it could be dissected with relative ease and was removed. Pathological diagnosis indicated a type B1 tumor with no capsular invasion according to the World Health Organization classification, and a diagnosis of Masaoka stage I thymoma was made. No continuity with the normal thymus tissue was seen, and the thymoma was considered to be derived from ectopic thymic tissue in the pleura.


World Journal of Surgical Oncology | 2011

Alpha-fetoprotein-producing primary lung carcinoma: A case report

Masahiro Kitada; Keisuke Ozawa; Kazuhiro Sato; Yoshinari Matsuda; Satoshi Hayashi; Yoshihiko Tokusashi; Naoyuki Miyokawa; Tadahiro Sasajima

Alpha-fetoprotein (AFP)-producing lung adenocarcinoma is a rare type of lung cancer, with its characteristics not yet fully clarified. We recently encountered a case of this type of lung cancer. The patient was a 69-year-old man who consulted an internist with the chief complaint of epigastric pain. Chest X-ray and CT revealed a lobulated mass measuring 70 mm in diameter in the right lower lung field and a metastasis in the right hilar lymph nodes. Of the tumor markers, the serum AFP was elevated (4620 ng/ml), and the serum carcinoembryonic antigen and carbohydrate antigen 19-9 were also slightly elevated. Transbronchial lung biopsy revealed the diagnosis of lung cancer. Under thoracoscopic assistance, right lower lobectomy + mediastinal lymph node dissection was carried out. Immunostaining showed the tumor cells to be AFP-positive. The tumor was thus diagnosed as an AFP-producing lung adenocarcinoma. The patient followed an uneventful clinical course after the surgery, with serum AFP decreasing to the normal range by about 2 weeks after the surgery. As of this writing, no sign of tumor recurrence has been noted. This case is presented here with a review of the literature.


The Japanese Journal of Thoracic and Cardiovascular Surgery | 2010

Clear cell carcinoma of the lung

Masahiro Kitada; Keisuke Ozawa; Kazuhiro Sato; Satoshi Hayashi; Naoyuki Miyokawa; Tadahiro Sasajima

We present here in the case of a patient who underwent resection of clear cell carcinoma of the lung, a rare histological type. A screening test of the 71-yearold woman revealed a 2.0-cm lesion in S4 of the right lung with a diagnosis of bronchioloalveolar carcinoma before resection. Under the guidance of video-assisted thoracoscopy, right middle lobe resection and mediastinal lymph node dissection were performed. The histopathological examination showed clear, slightly acidophilic tumor cells rich in fine granular components proliferating in an alveolar fashion. Immunostaining was diagnostically useful, distinguishing clear cell carcinoma from lung metastasis of renal clear cell carcinoma or clear cell squamous cell carcinoma.


World Journal of Surgical Oncology | 2013

Combined large cell neuroendocrine carcinoma with giant cell carcinoma of the lungs: a case report

Satoshi Hayashi; Masahiro Kitada; Kei Ishibashi; Yoshinari Matsuda; Naoyuki Miyokawa

Combined large cell neuroendocrine carcinoma of the lungs (combined LCNEC) with giant cell carcinoma is extremely rare. A 65-year-old man was found to have an abnormal shadow in his left lung field. Computed tomography revealed a solid, round mass measuring 2.8 × 2.2 cm that was located in the left S9. The patient underwent left lower lobectomy and mediastinal lymph node dissection. Histopathological examination revealed an LCNEC, combined with giant cell carcinoma. The patient received by S-1 (TS-1, an oral fluoropyrimidine) chemotherapy, and he has been disease-free for over 8 months. Combined LCNEC with giant cell carcinoma is an extremely rare tumor with high malignant potential, and thus, multidisciplinary therapy and close follow-up are advised.

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Satoshi Hayashi

Asahikawa Medical University

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Kei Ishibashi

Asahikawa Medical University

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Yoshinari Matsuda

Asahikawa Medical University

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Yoshinobu Ohsaki

Asahikawa Medical University

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Tadahiro Sasajima

Asahikawa Medical University

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Nana Takahashi

Asahikawa Medical University

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Keisuke Ozawa

Asahikawa Medical University

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Satoshi Okazaki

Asahikawa Medical University

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