Publications by authors named "Rikiya Okuyama"

Article Synopsis
  • Cytological diagnosis for gastric submucosal spindle cell tumors is difficult due to the similarities in tumor characteristics, which include GISTs, leiomyomas, and schwannomas.
  • A study reviewed EUS-FNA specimens from different tumor types to identify key cytomorphological features that can help differentiate between them.
  • An algorithm was created based on significant features, which improved diagnostic accuracy among cytologists after training, allowing for more effective on-site evaluations of these tumors.
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Aims: Recent studies have provided the concept of invasive intramucosal colorectal carcinoma (CRC), and a case of intramucosal CRC with lymphatic invasion has been reported; however, the characteristics of such cases and the risk of lymph node metastasis have never been investigated. Therefore, we aimed to assess the pathological characteristics of intramucosal CRCs with lymphovascular invasion as well as the possibility of lymph node metastasis as an indication for additional surgery.

Methods And Results: To delineate the histological features of intramucosal CRCs with lymphovascular invasion, we analysed several histological features and compared their incidence among nine such cases, as well as 20 other cases of intramucosal CRCs without lymphovascular invasion.

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Lobular endocervical glandular hyperplasia (LEGH) is an endocervical glandular hyperplastic lesion containing pyloric gland-like mucin, and has recently been recognized as a precursor lesion of malignant glandular lesions of the endocervix. The pyloric gland-like mucin contained in LEGH and gastric-type adenocarcinoma is observed as golden-yellowish by Papanicolaou staining. However, to our knowledge, the chronological course of the endocervical cytology of LEGH, eventually resulting in malignancy, has never been demonstrated to date.

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L-type amino acid transporter 1 (LAT1) has an essential role in cell proliferation especially in neoplasms. Although immunohistochemical expression of LAT1 has been investigated in invasive esophageal carcinoma, its expression in intraepithelial neoplasia (IEN) has not been reported. Further, classification of esophageal IEN is currently different between the World Health Organization (WHO) and Japanese criteria.

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