The present study reports on a case of extra-nodal natural killer/T cell lymphoma, nasal-type (ENKL), stage IIEA, in a 50-year-old woman who presented with a white tumor on a refractory ulcer on the gum. Concurrent chemoradiotherapy was administered, and effected a partial response. However, tumor recurrence was observed 5 months after the final diagnosis, and the patient succumbed 1 month after recurrence. Although a definitive treatment for ENKL has yet to be established due to its rarity, radiation therapy (RT) is crucial to therapy, as ENKL is very sensitive to RT. However, treatment with radiation levels above 50 Gy with an extended RT field are required for a favorable outcome. The development of novel chemotherapy regimens may therefore be useful. Additionally, autologous or allogenic hematopoietic stem-cell transplantation may prove to be a promising approach.