Features of intestinal T-cell lymphomas in Chinese population without evidence of celiac disease and their close association with Epstein-Barr virus infection

BACKGROUND: Intestinal T-cell lymphoma (ITCL) is a heterogeneous lymphoid neoplastic group with variable clinical and pathological features. ITCL in oriental countries is different from enteropathy-type intestinal T-cell lymphoma (ETCL) in relation to celiac disease and Epstein-Barr virus (EBV). The objective of this study was to investigate the clinicopathological features, immunophenotype, expression of cytotoxic molecule (TIA-1), T-cell receptor (TCR)-gamma gene rearrangement, and Epstein-Barr virus (EBV) latent infection in primary ITCL without celiac disease in Chinese. METHODS: The clinical data of 42 patients were analyzed, and the patients were followed up. Compared with human reactive lymphoid tissues, in situ hybridization for EBER1/2, polymerase chain reaction for TCR-gamma gene rearrangement, and immunohistochemical staining for immunophenotypes, TIA-1 and EBV latent membrane proteins (LMP-1) were investigated. Survival curves of different clinicopathological features, immuno-phenotypes, expression of LMP1, TCR-gamma gene rearrangement and therapy were analyzed. RESULTS: Three fourths of the patients suffered from ITCL in China were men with a peak age incidence in the 4th decade. Common presenting features included fever and hemotochezia. The prognosis was poor with a median survival of 3.0 months. The lesions were mostly localized in the ileocecum and colon. About 38/42 (90.5%) patients demonstrated pleomorphic medium-sized on large cells. Histological features of celiac disease were rarely seen. All 42 patients with ITCL revealed CD45RO positive. Neoplastic cells partially expressed T-cell differentiated antigens (CD3epsilon, CD4, CD8) and NK cell associated antigen (CD56). The positive frequency of CD3epsilon, CD4, CD8 and CD56 was 28/42 (66.7%), 7/42 (16.7%), 10/42 (23.8%) and 12/42 (28.6%) respectively. Thirty-nine cells (92.9%) expressed TIA-1, but none expressed CD20 and CD68. More than half of the patients (64.3%, 64.3% and 59.5%) revealed TCR-gamma gene rearrangement by three different TCR-gamma primers respectively. EBER1/2 was detected in 41 (97.6%) of the 42 patients. The expression frequency of LMP-1 was 38.1% (16/42). CONCLUSIONS: Primary ITCL without celiac disease in Chinese is a special highly EBV-associated clinicopathological entity. There are few similarities in patients with celiac disease in western countries. A small proportion of primary ITCLs in Chinese and extranodal NK/T-cell lymphoma of nasal type belong to the same spectrum.