Primary Intestinal Malignant Lymphomas Associated With Celiakia ? A Pathologist´s Review

Celiakia represents a prototype of chronic antigenic stimulation and autoimmune dysregulation leading to the accumulation of reactive cytotoxic intraepithelial lymphocytes (IEL) and small intestinal mucosal injury. These lymphocytes possess a potential of transformation, gaining an aberrant phenotype and genotype during their clonal expansion. The development of type I enteropathy ?associated T-cell lymphoma (EATL) in patients with celiac disease might represent a gradual multistep transformation process starting from the increasing accumulation of IEL, and developing through the refractory celiac disease I and refractory celiac disease II, the last representing probably a lymphoma in situ. These transformational stages of the progressing celiac disease are showing increasing risk of type I EATL development, and decreasing survival of the patients. The whole process of progressing EATL lymphomagenesis resembles the hyperplasia-adenoma-dysplasia-adenocarcinoma sequence of colorectal carcinomas. Similar to the already more understood multistep developmental process from CD to type I EATL, an overt type II EATL lymphoma might represent a final step in a process of progression from IEL, representing the lymphoma precursors. However, the patients with the type II lymphoma show signs of celiakia neither clinically nor morphologically and the pathogenetical link to CD is missing. The lymphomagenesis of EATL type II seems to utilize activation of other pathways than that of type I. The recent data support the attempts to set apart the type II from the EATL category and to rename it.