The lesion is abnormal, that is for sure. There isn't an exact definition for big of a lesion because they can get bigger. This may mean your lung, breast or kidney(s) are/is inflamed. Also, this could be breast cancer, lung cancer, Wilm's tumor, chronic nephritis, neuroblastoma (highly unlikely for your age), and of course, benign tumor. I recommend taking this situation to your oncologist.
Hi,
What are the symptoms present? Can you elaborate on the lesion? I understand your concern regarding your CT scan result and many factors such as your medical history, results of other diagnostic tests, symptoms, and also your family history needs to be considered. It is best that you discuss the results with your attending physician for proper evaluation. Take care and do keep us posted.