title: Multiple lesions of gastrointestinal tract invasion by monomorphic epitheliotropic intestinal T-cell lymphoma, accompanied by duodenal and intestinal enteropathy-like lesions and microscopic lymphocytic proctocolitis: a case series.
abstract: BACKGROUND
  In East Asia, monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL), previously known as type II enteropathy-associated T-cell lymphoma (EATL), occurs more frequently than type I EATL, and coeliac disease is rare.
  
  
  METHODS
  Here we present four cases of MEITL in Japanese patients, including the endoscopic and pathological findings of their duodenal and colorectal lesions. Tumor specimens obtained from duodenal, intestinal, and colorectal biopsies in all four patients showed a diffuse intramucosal infiltration of small to/or medium-sized lymphoma cells and numerous atypical intraepithelial lymphocytes (IELs). These cells were immunohistologically positive for CD103, CD3, CD7, CD8, CD56, and T-cell intracellular antigen-1. Upper and lower gastrointestinal and antegrade double-balloon endoscopy revealed foci of edematous mucosa, with or without villous atrophy, in the non-neoplastic mucosa. Histological studies demonstrated duodenal and intestinal enteropathy-like lesions as well as microscopic (lymphocytic) proctocolitis with increased CD3- and CD8-positive and CD56-negative T-IELs in all four patients. The clinicopathological findings of the non-neoplastic lesions were similar to those characteristic of coeliac disease, suggesting that variants of coeliac disease may be present in the prodromal lesions of MEITL.
  
  
  CONCLUSIONS
  Our study supports the need for random gastrointestinal biopsies to determine tumor spread, the features of MEITL in the particular patients, and the presence of prodromal non-neoplastic lesions.
authors.affiliation: Department of Gastroenterology and Medicine, Faculty of Medicine, Fukuoka University, Fukuoka, 814-0180, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Ishibashi
authors.affiliation: Department of Pathology, Faculty of Medicine, Fukuoka University, Fukuoka, 814-0180, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nimura
authors.affiliation: Department of Gastroenterology and Medicine, Faculty of Medicine, Fukuoka University, Fukuoka, 814-0180, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kayashima
authors.affiliation: Division of Medical Oncology, Hematology and Infectious Diseases, Faculty of Medicine, Fukuoka University, Fukuoka, 814-0180, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Takamatsu
authors.affiliation: Department of Gastroenterology and Medicine, Faculty of Medicine, Fukuoka University, Fukuoka, 814-0180, Japan.
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Aoyagi
authors.affiliation: Department of Gastroenterology, Clinical Research Institute, National Hospital Organization, Kyushu Medical Center, Fukuoka, 810-8563, Japan.
authors.forename: Naohiko
authors.initials: N
authors.lastname: Harada
authors.affiliation: Department of Hematology, Clinical Research Institute, National Hospital Organization, Kyushu Medical Center, Fukuoka, 810-8563, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Kadowaki
authors.affiliation: Department of Pathology, Saiseikai Kumamoto Hospital, Kumamoto, 861-4193, Japan.
authors.forename: Takihiko
authors.initials: T
authors.lastname: Kamio
authors.affiliation: Department of Gastroenterology and Medicine, Faculty of Medicine, Fukuoka University, Fukuoka, 814-0180, Japan.
authors.forename: Shotaro
authors.initials: S
authors.lastname: Sakisaka
authors.affiliation: Department of Pathology, Faculty of Medicine, Fukuoka University, Fukuoka, 814-0180, Japan. m-take@adm.fukuoka-u.ac.jp.
authors.forename: Morishige
authors.initials: M
authors.lastname: Takeshita
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism*; D058527:Enteropathy-Associated T-Cell Lymphoma / Q000175:diagnosis* / Q000378:metabolism; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000473:pathology*; D007564:Japan; D008297:Male; D008875:Middle Aged; D039102:Poly(A)-Binding Proteins / Q000378:metabolism; D011350:Proctocolitis / Q000175:diagnosis* / Q000378:metabolism; D000074019:T-Cell Intracellular Antigen-1; D013601:T-Lymphocytes / Q000378:metabolism / Q000473:pathology
chemical_list: D015703:Antigens, CD; D014408:Biomarkers, Tumor; D039102:Poly(A)-Binding Proteins; D000074019:T-Cell Intracellular Antigen-1; C071558:TIA1 protein, human
keywords: Enteropathy; Gastrointestinal T-cell lymphoma; Intraepithelial lymphocytes; Microscopic proctocolitis