I have a lump on the back of my neck. all my bloodwork is normal. i did have a ct of chest and abdomen and it was normal. could this be lymphoma. i am a past cancer patient. will a ct scan of the chest and abdomen show the neck?

There is not enough information given by you to tell the nature of the lump on the back of your neck. It is important to discuss with your clinician rather than being anxious. It may be that the would do a biopsy or removal of the lump but you best discuss with your doctor. It depends on how high the cut went when they did the CT and that also you should ask your doctor.