An uncommon mature T-cell lymphoma of intraepithelial lymphocytes. It usually arises from the small intestine, most commonly the jejunum or ileum. Other less frequent primary anatomic sites include the duodenum, stomach, colon, or outside the gastrointestinal tract. It is seen with increased frequency in regions with a high prevalence of celiac disease. The disease is enteropathy-associated T-cell lymphoma (MONDO_0019473). Also known as: EATL, EATL, type I, ETTL, enteropathy associated T-cell lymphoma, enteropathy-associated T-cell lymphoma, type I, enteropathy-type T-cell lymphoma, intestinal T-cell lymphoma.