Pathological and immunohistological findings and genetic aberrations of intestinal enteropathy-associated T cell lymphoma in Japan

Takeshita M, Nakamura S, Kikuma K, Nakayama Y, Nimura S, Yao T, Urabe S, Ogawara S, Yonemasu H, Matsushita Y, Karube K & Iwashita A
(2011) Histopathology 58 , 395–407
Pathological and immunohistological findings and genetic aberrations of intestinal enteropathy‐associated T cell lymphoma in Japan Aims: To elucidate the clinicopathological findings of primary intestinal enteropathy‐associated T cell lymphoma (EATL) in Japan, a non‐endemic area for coeliac disease. Methods and results: Of the 24 cases, four (17%) had large‐cell lymphoma (type I), and the remaining 20 (83%) had medium‐sized lymphoma (type II). Lymphoma cells of the three type I cases were CD56‐positive. Only one (4%) case showed typical CD56‐ and CD8‐negative and CD30‐positive type I EATL. In type II EATL, lymphoma cells of the 16 (80%) and 11 (55%) cases were positive for CD56 and CD8, respectively. Intramucosal tumour spreading and adjacent enteropathy‐like lesions were detected in 15 (71%) and 16 (76%) of 21 cases, with a severe increase of intraepithelial lymphocytes (IELs) in 12 (57%). IELs of enteropathy‐like lesions in five (24%) cases expressed T‐bet, with no cases of CD30‐positive IELs. Characteristic findings from comparative genomic hybridization of 15 cases indicated gains of 8q2 (47%), Xp (53%) and Xq (73%), but no gain of 9q3. Regarding, human leucocyte antigen (HLA) status, six cases examined did not express the DQB1*02 allele. Conclusions: Japanese EATL exhibited different histology, cytogenetic findings and HLA status from those of typical type I EATL. The rare incidence of coeliac disease may influence the tumour cell characteristics of EATL and IELs.