Yes, a lesion can be many things. I had a lesion on my right temporal lobe that turned out to be in fact a tumor. Has your husband had any symptoms to go along with this diagnosis of a lesion? Anything along the lines of headaches, seizures, vision changes etc? You can expect future MRI's and possibly CT scans. If it turns out to be a tumor and surgery may be an option then you can look forward to more testing such as neuropsychological testing, WADA, IQ (I can explain these in more detail if you'd like me to). I had my surgery 5.5 years ago and it was successful in removing the entire tumor. I also had refractory epilepsy as a result of the tumor (meaning medication did not control the seizures that I had as a result of the tumor) and I was seizure free for 4 years post op. I now only have an occasional seizure due to certain environmental conditions. I am once again on AED's (anti-epileptic drugs) to control constant migraines and seizures, which is working quite successfully I might add.
If you'd like to know more about the surgery let me know.
It's a frightening process to go through, but it can be a very enlightening one also. It brought me a lot closer to my family and really made me appreciate the little things in life.