@deborah67, It’s always scary when there’s a new finding. I agree with the others, that 4mm is small, and a wait and see approach appears to be appropriate. Many people find lung nodules on CT screenings that are non-cancerous. You are correct that some lung cancers are aggressive and can grow very quickly, but there will be other signs if that is happening. Be sure to reach out to your doctor if you have any chest related symptoms; other lymph node swelling (lumps near your collar bone), a cough that won’t go away, any feelings of throat or chest heaviness or spasms, difficulty swallowing or wheezing when you breathe. Hopefully the nodule is nothing to be concerned about. I’m encouraged that it was identified at this small size, and can be monitored now.