Extranodal NK/T cell lymphoma, nasal type, of the small intestine diagnosed by double-balloon endoscopy.

Extranodal NK/T-cell lymphoma (ENKL), nasal type, is rare and the small intestine is quite extraordinary as a primary lesion site. We report a 47-year-old man with ENKL of the small intestine. He was referred to our hospital because of bloody stool and the diagnosis was made by double-balloon endoscopy (DBE) of the small intestine without surgical procedure. His clinical stage was IVB and he was categorized in group 4 by prognostic index of ENKL. He went into complete remission (CR) after intensive chemotherapy (DeVIC) and subsequently underwent allogeneic bone marrow transplantation (BMT). Although he remained in CR for about 8 months after BMT, he died of disease recurrence 14 months after the diagnosis was made. ENKL of the small intestine follows a highly aggressive course. We describe the usefulness of DBE for diagnosis and management for ENKL of the small intestine. Additional cases, however, should be accumulated to establish optimal treatment strategy.