Hi, its difficult to tell if its a tumor, unless a biopsy is done. A biopsy facilitates a histological study of cells, which gives you a definite diagnosis. If a biopsy has been done six months back and it was negative for malignancy, Then even if a tumor is detected now, the prognosis is good, provided the biopsy is has been taken from the same site. So once you have the diagnosis you will know what measures or precautions you need to follow. Good luck with your therapy. Regards.