Brain lesion or tumor

Hi,
My first symptoms were numbness in my right arm. After emergency room visit and multiple tests, a small lesion was found on the upper left side.(MRI) Small seizures followed in my right arm but are controlled by 1000 mg of Keppar. A lumbar puncture was preformed with all tests coming back negative or normal. A month later another MRI showed lesion still there. Neorologist feels it dose not have the morphology of a tumor but has not ruled it out. A biopsy could cause paralysis of my right side. General health is good at age 41. My main concern is cancer or ALS
What are some possible diagnosis and possible outcomes?

[Demiguise]

A stable benign lesion has been referenced as a tumor but
generally it's a wait-see w/ other clinical findings before
they use the T word. If you had a seizure, why didn't they do a
EEG immediately. A sm-tumor is always questionable so repeats of
mri are a great tool. Some tumors turn out to be cysts. a
seizure generally affects more than one limb & also the eyes
even when mild. Get copies of mri for files to track yourself.
Any labs done or just found accidently from vascular searching?
Scarey & would hold off on surgery. Maybe Dr meant paralysis if
he did procedure? There are many top neuro-surgeons I'd consult
w/ first. Some radiologists do fast scan/reports. Keep a file.