Primary lung lymphoma is an uncommon tumor, which constitutes 0.5% of primary lung cancer, and 3% of extranodal lymphoma. The most frequent radiologic presentation of pulmonary parenchymal lymphoma is single mass or nodule. But we have experienced a case which was radiologically presented as patchy lung infiltration at first, and then progressive multiple reticulonodular infiltrations in lung. A 48-year-old woman was admitted to the hospital because of fever and cough. Chest PA obtained on admission revealed multiple patchy infiltration. Eventually, open lung biopsy was performed and the specimen disclosed extranodal NK/T cell lymphoma, and in bone marrow aspiration, hemophagocytosis was present. We report a case of primary extranodal NK/T cell lung lymphoma presented as patchy lung infiltrations, which was treated with chemotherapy.