NK/T cell lymphoma developed during the follow up period of Kimura's disease

Kimura's disease is a rare chronic inflammatory disease of the lymphoid organs and this presents as painless nodules in the head and neck area. It occurs endemically in the Far East Asia and sporadically in the West. Its exact etiology is unknown and it has no potential to transform into malignant disease. However, it is often confused with malignant disease such as malignant lymphoma. We report a case of NK/T cell lymphoma patient who had Kimura's disease in the right thigh 3 years ago. She then suffered from sudden dyspnea. Radiological studies revealed multiple small nodules scattered in both lung fields. NK/T cell lymphoma was diagnosed by open lung biopsy. In addition, Epstein-Barr virus (EBV) was detected in the previous site of Kimura's disease and lung nodule by molecular pathologic examination. To the best of our knowledge, this is the first case of NK/T cell lymphoma complicating Kimura's disease with coexisting chronic EBV infection.