My mother has had COPD for 11 years and had a bad "flareup" last year which put her in the hospital and on oxygen 24/7 for the first time. While she was there she had a CT scan which showed a "lesion" show up on her lung. She is 85 and did not want to have PET scan done. Now it is 1 year later and she is still on oxygen 24/7 . Her pulmonologist told her today that she is expelling carbon dioxide well and he thinks the " shadow" is most likely malignant. My mom still chooses to not have a PET scan. She is actually doing pretty well except for getting tired after a full day and her breathing is a bit worse. Is it possible this could be something else less serious?