Masaya Iwamuro1, Katsunori Matsueda2, Takahide Takahashi3, Sizuma Omote4, Takehiro Tanaka4, Daisuke Ennishi5, Fumio Otsuka6, Tadashi Yoshino4, Hiroyuki Okada7. 1. Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama iwamuromasaya@yahoo.co.jp. 2. Department of Gastrointestinal Oncology, Osaka International Cancer Institute, Osaka. 3. Division of Medical Support, Okayama University Hospital, Okayama. 4. Department of Pathology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama. 5. Department of Hematology and Oncology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama. 6. Department of General Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan. 7. Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama.
Abstract
OBJECTIVE: Flow cytometry has not been widely used in routine clinical practice for the diagnosis of gastrointestinal lymphoma; this is mainly because of the absence of an appropriate protocol. Here, we established a protocol for flow cytometric analysis of a single biopsy specimen from the gastrointestinal mucosa and investigated its sensitivity and specificity. DESIGN: In this prospective study, we enrolled patients with previously diagnosed gastrointestinal lymphoma and patients with gastrointestinal lesions that were suspected to be lymphoma. RESULTS: Overall, 15 patients with gastric extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (N=8), duodenal follicular lymphoma (grade 1; N=5), and benign lymphoid hyperplasia (ileum, N=1, and rectum, N=1) were included in this study. Of these, lymphocytes were isolated from 14 patients (93.3%). There were 200,000-1,500,000 viable cells per patient. Biopsy specimens from 10 out of the 12 patients with lymphoma were positive for light chain restriction; the two patients with benign lymphoid hyperplasia showed negative results. CONCLUSIONS: An adequate number of lymphocytes for flow cytometry could be isolated from a single specimen of endoscopic mucosal biopsy from 93.3% of the patients. Overall, the sensitivity of flow cytometric analysis of light chain expression for the diagnosis of B-cell lymphoma was 83.3%, and the specificity was 100%. Although further investigation is required as the sample size of the present study was small, our study suggests a potential option for diagnosing B-cell lymphoma in the gastrointestinal mucosa.
OBJECTIVE: Flow cytometry has not been widely used in routine clinical practice for the diagnosis of gastrointestinal lymphoma; this is mainly because of the absence of an appropriate protocol. Here, we established a protocol for flow cytometric analysis of a single biopsy specimen from the gastrointestinal mucosa and investigated its sensitivity and specificity. DESIGN: In this prospective study, we enrolled patients with previously diagnosed gastrointestinal lymphoma and patients with gastrointestinal lesions that were suspected to be lymphoma. RESULTS: Overall, 15 patients with gastric extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (N=8), duodenal follicular lymphoma (grade 1; N=5), and benign lymphoid hyperplasia (ileum, N=1, and rectum, N=1) were included in this study. Of these, lymphocytes were isolated from 14 patients (93.3%). There were 200,000-1,500,000 viable cells per patient. Biopsy specimens from 10 out of the 12 patients with lymphoma were positive for light chain restriction; the two patients with benign lymphoid hyperplasia showed negative results. CONCLUSIONS: An adequate number of lymphocytes for flow cytometry could be isolated from a single specimen of endoscopic mucosal biopsy from 93.3% of the patients. Overall, the sensitivity of flow cytometric analysis of light chain expression for the diagnosis of B-cell lymphoma was 83.3%, and the specificity was 100%. Although further investigation is required as the sample size of the present study was small, our study suggests a potential option for diagnosing B-cell lymphoma in the gastrointestinal mucosa.