Current management of nasal NK/T-cell lymphoma.

Nasal natural killer (NK)/T-cell lymphoma--classified as extranodal NK/T-cell lymphoma (ENKTL), nasal type, by the World Health Organization--is a non-Hodgkin lymphoma that is almost always associated with Epstein-Barr virus. Up to 75% of ENKTL cases occur in the upper aerodigestive tract, primarily the nasal cavity. It is the most common type of peripheral T-cell lymphoma in many Asian countries. Histologic diagnosis is essential, and staging consists of bilateral bone marrow biopsy and imaging of the neck, thorax, abdomen, and pelvis. There is a marked dichotomy in treatment and survival between localized and disseminated disease. Since disease incidence is rare even in prevalent areas, experience is limited and most treatment protocols are consensus-guided. ENKTL is both chemosensitive and radiosensitive. Early-stage, localized nasal disease is highly curable with combination therapy, but the optimal dose, combination, and sequence of radiotherapy and chemotherapy are still undefined. For patients with disseminated and extranasal disease, either at initial presentation or at relapse, the prognosis is poor. For disseminated and refractory cases, the 5-year survival rate is below 10%, and better methods of treatment are needed.