A right middle lobe micronodule, meaning that a nodule less than five millimeters in diameter can be seen in the middle lobe of the right lung, may be caused by inflammation. However, if the micronodule is a growing nodule, it may be a precursor to cancer and should be seen promptly to identify the cause. Lung micronodules are usually less than five millimeters in diameter, and some are even less than three millimeters, and in most cases, they are a disease that is detected by high-resolution CT or MRI. Micronodules in the middle lobe of the right lung are mostly caused by inflammatory lesions, because the bronchial tubes in the middle lobe are thin and long, and easily blocked to form inflammation, so they are easy to be infected and thus form infected nodules. This is a benign disease and there is no need to be nervous, just need to observe the condition of the nodules regularly. However, if the micronodule continues to grow beyond six to eight millimeters and is accompanied by early signs of cancer such as short burrs, lobulation, and pleural pulling signs, this indicates that the right lobe micronodule is beginning to undergo malignant changes, and should be actively examined for lung cancer. If you feel uncomfortable, you should go to the hospital and receive treatment in time to avoid delaying your condition.