High frequency of EBV association and 30-bp deletion in the LMP-1 gene in CD56+ lymphomas of the upper aerodigestive tract

Natural killer (NK)/T‐cell lymphomas are frequently associated with Epstein–Barr virus (EBV), and usually lack TCR gene rearrangement. Studies from Asia have reported frequent deletion in the LMP‐1 gene in EBV‐associated nasopharyngeal carcinoma (NPC). The present study aims to investigate LMP‐1 and TCRγ gene status in upper aerodigestive tract lymphomas. A total of 43 cases were classified into T‐, B‐, and NK/T‐cell tumors based on the phenotype expressions of CD3+/CD20–/CD56–, CD3–/CD20+/CD56–, and CD3+/CD20–/CD56+, respectively. The presence of EBV in the tumor was confirmed by EBV early RNA‐in situ hybridization. LMP‐1 gene deletion and TCR γ gene rearrangement were analyzed by polymerase chain reaciton on paraffin‐embedded tissues. There were 20 NK/T‐, eight T‐, and 15 B‐cell phenotype lymphomas in the present series, and EBV was detected in 19 (95%), two (25%), and three (20%) cases in the respective groups. All EBV+ cases carried 30‐bp deletion in the LMP‐1 gene, and two of the NK/T‐cell cases were infected by both the wild type and deleted strains. Five (25%) of the NK/T‐cell phenotype lymphomas showed rearranged TCR γ gene. The present study revealed a high frequency of EBV association, and a high frequency of 30‐bp deletion in the LMP‐1 gene in the virus in the present series of lymphoma. The NK/T‐phenotype lymphomas are comprised of both NK‐cell and cytotoxic T‐lymphocyte‐derived tumors.