Sometimes those scans can give an idea of a nodule but also an infection can appear as ground glass (weird identifier, right?). Mine was actually an infection in my lung and my esophageal stage was stage 3 because it was in lymph nodes.
But it's been almost 2 1/2 years since my treatments followed by esphogectomy and I'm doing great!! Don't focus on the labels of stage; take one day at a time, eat lots of protein and high calories with the help of an oncology dietician.
Not a piece of cake, but it's definitely worth giving it your best.