Abstract: Objective:To investigate the clinicopathological features,immunophenotype and molecular genetics of enteropathic T-cell lymphoma(ETCL).Methods:The histopathological appearance,the immunophenotype,immunoglobulin heavy chain,the gene clonality rearrangement of T-cell receptor(TCR) of a ETCL cases were observed,and relevant references were reviewed.Results:Segmental ulcers were found in ileum and right colon.Superficial ulcer involving the ileal mucosa and submucosa,the deeper ulcerative lesions invasing the full thickness and abnormal lymphocytes encroached all layers of the intestinal wall in the context of inflammation of ileum and colon were observed under microscope.According to immunophenotype,the immunophenotype of CD43+,CD45RO+,CD56+,TIA1+,GB+ and PF+ of the tumor cells presented postive results,but the expression of CD3-,CD3(monoclone) CD30-,EMA-,CD20-and CD79a were negative.According to TCR- gene rearrangement,JVⅠ and JVⅡshowed positive,and the result of hybridization in situ of EBER was negative.Conclusions:ETCL occurs most in young men with no specific symptoms.Its progresses is rapidly and the result of prognosis is poor.The multiple ulcer in intestinal canal and TCR- gene rearrangement are its main characteristic.