[Successful treatment with high-dose methotrexate/cytarabine regimen in a patient in SMILE regimen-resistant extranodal natural killer/T-cell lymphoma].

: A 28-year-old man complained of pain in the oral mucosa and pharynx in March 2011, and then developed fever and generalized swelling of the cheek. In March 2012, a gum biopsy led to a diagnosis of extranodal natural killer/T-cell lymphoma (ENKL). (18)F-FDG-PET revealed significant uptake in the mouth, tonsils, jawbone, shoulder blade, humerus, ilium, femur, and spleen. After two courses of the SMILE (dexamethasone, methotrexate (MTX), ifosfamide, L-asparaginase, etoposide) regimen, the response was stable disease. However, a high-dose MTX/cytarabine (MA) regimen was effective. After three courses of the MA regimen, a partial response was achieved. Then, allogeneic bone marrow transplantation from an unrelated donor was performed. At 10 months after transplantation, there was no sign of recurrence. Although the optimal treatment for ENKL refractory to the SMILE regimen has yet to be established, our case suggests the MA regimen to be a potentially effective treatment option.