Extranodal NK/T-cell lymphoma, nasal type, had a suspicious background of presentation of chronic active EB virus infection

Abstract

Chronic active Epstein–Barr virus (EBV) infection (CAEBV) has an indolent clinical course and a highly variable presentation, with symptoms including fever, lymphadenopathy, and hepatosplenomegaly. The clonality of CAEBV, which frequently involves T and/or natural killer (NK) cells, has been suggested by the monoclonal patterns of the virus. Extranodal NK/T-cell lymphoma, nasal type (ENKL), is an EBV-associated lymphoma and is most common among people in their 40s to 50s, but rare in children. A 12-year-old boy was diagnosed as having ENKL, which was complicated owing to a high number of EBV-DNA copies and EBV titer in the peripheral blood. ENKL resolved with radiochemotherapy, but the number of EBV-DNA copies did not decrease. Thus, ENKL with CAEBV as a background disease was diagnosed and hematopoietic stem-cell transplantation was performed. Complete remission of CAEBV was achieved. Thus, when diagnosing childhood-onset ENKL, CAEBV should always be considered as a possible underlying disease.