Abstract
Pulmonary infections and lung cancer can resemble each other on radiographic images, which makes it difficult to diagnosis accurately and apply an appropriate therapy. Here we report two cases that two postoperative patients with lung adenocarcinoma developed diffuse nodules in bilateral lungs in a month which needed to be distinguished between metastatic malignancies and infectious diseases. Although there are much similarities in disease characteristics of two cases, patient in case one was diagnosed as acute miliary pulmonary tuberculosis (TB) while patient in case two was diagnosed as metastatic disease. The symptoms and pulmonary foci on CT scan of patient in case one improved distinctly after the immediate anti-TB treatment, but the disease of patient in case two progressed after chemotherapy. These findings caution us that differential diagnosis is crucial and have significance in guiding clinical work.