A 53-year-old woman was admitted to our hospital in April 1995, because of nasal obstruction, bloody rhinorrhea and hearing disturbance. She had no lymphadenopathy or skin eruptions. Laboratory examinations revealed a WBC count of 2.7 x 10(9)/L without abnormal cells, positive serum anti-HTLV-I antibody, normal lactate dehydrogenase and normal calcium level. MRI showed an epipharyngeal mass. No involvement was detected by CT scanning of the chest and abdomen, 67Ga scintigraphy and bone marrow biopsy. The pathological diagnosis of the biopsied specimen from the epipharyngeal mass was T-cell diffuse lymphoma, pleomorphic type. Monoclonal integration of HTLV-I proviral DNA was detected in lymphoma cells, which confirmed a diagnosis of extranodal adult T-cell leukemia lymphoma primarily involving the epipharynx. She was treated with CAMBO-VIP regimen followed by adjuvant involved-field radiotherapy and she continues to be in complete remission as of April 1996.