hi @ashscott1012 - it's always worrying when an unexpected finding shows up on imaging. cancer generally gets bigger, not smaller. that said, sometimes there can be a difference in the way a radiologist measured the mass/nodule, or a difference from machine to machine. a PET scan would give additional information (the higher the uptake, the more likely it's malignant.) but the only way to know for sure what you're dealing with is a biopsy. It's good he's seeing the pulmonologist next week. I expect they will order the PET scan (as recommended by the radiologist) and based on that result, decide what the best next step would be. please let us know how the appointment goes.