RESUMEN
NK-cell lymphoma, distinct clinicopathologic entity, almost always occurs in the naso-sinal region. NK-cell lymphomas of other extranodal sites have also been recognized in previous case reports, but very rare. As far as we know, only four cases of primary pulmonary NK-cell lymphoma were reported worldwide. We experienced a case of primary pulmonary NK-cell lymphoma. A 54-year-old man was admitted because of cough and chest discomfort. The chest CT shows multifocal ground-glass and nodular opacities in both lungs. Video Assisted Thoracoscopy (VATS) was performed to assess the lung lesion. The tumor cells were characterized by cytoplasmic CD3 (+), CD56 (+), T-cell receptor antigen (-), Epstein-Barr Virus (+) and T-cell gene rearrangement (-), These findings were compatible with NK-cell lymphoma. So we performed the whole body Flurodeoxyglucose-Positron Emission Tomography (FDG-PET) to exclude any other lesion. The FDG-PET showed multiple hypermetabolic lesions only located in both lungs. The patient underwent 6 cycles of chemotherapy according to a CHOP regimen. Now his disease state is complete remission. To our knowledge, this is the first case of primary pulmonary NK-cell lymphoma in Korea.