My dad has what doctors think its lymphoma in the brain, they are not sure what it is, can it be identified without drilling his skull, ?

Check body: The first thing that must be done is to image the whole body to see if there is something that looks like lymphoma somewhere else other than the brain. A lump somewhere else may be easier to biopsy. If not, they must see what is there. These days, neurosurgeons are very precise in obtaining biopsies and the real risk lies in what area of the brain they see the problem in terms of side effects.

No: Without a biopsy it can not be certain what type of cancer is in the brain. These lesions can be similar to glioblastoma and the right diagnosis needs to be made as the treatment is different.