I'm a 19 year old female that went to the emergency room in early May because of severe chest pain and trouble breathing for a week. Since then I've gone through a lot of tests, including CT scans and PET scans. My CT shows a 3.5 cm mass in my anterior mediastinum, and PET scan shows a maximal SUV of the mass to be 4.47, with the maximum mediastinal blood pool SUV to be 3.54, but with no signs of metastasis. Results said findings were abnormal and showed signs of increased metabolic activity consistent with neoplasia. My primary care doctor's comment on the results said the mass needed a biopsy and showed signs of possible malignancy. Is it probable that I have cancer?