Extranodal NK/T-cell lymphoma: basic questions remain.

Extranodal natural killer/T-cell lymphoma (ENKTL), nasal type, is a distinct entity of non-Hodgkin lymphoma with interesting unique biologic and clinicopathologic features. The tumor is characterized by ethnic preponderance, a consistent association with Epstein-Barr virus (EBV) infection, peculiar histopathologic findings, and a predilection to affect primarily the upper aerodigestive tract, inclusive anatomically of the nasal cavity, nasopharynx, paranasal sinuses, oral cavity, hypopharynx, and larynx. The characteristic clinical features are nasal stuffiness, relentless, nonhealing ulcers, or symptoms due to obstruction of the aforementioned areas. Distant metastasis at time of diagnosis is uncommon.