Thanks for choosing health care magic for posting your query.
I have gone through your question in detail and I can understand what you are going through.
The kind of lump on the skin that you are describing has no relation to the migraine
of visual disturbance. Most probably the kind of lump fro your description appears to be a lipoma
. It is a soft, spongy mass which slips when trying catch it between fingers.
Its a benign lesion and nothing has to be done. It generally stays of the same size and doesn't cause any problem except for cosmetic if it is in a visible area.
Hope I am able to answer your concerns.
If you have any further query, I would be glad to help you.
In future if you wish to contact me directly, you can use the below mentioned link:
Wish you good health,
Dr. Srikanth Reddy M.D.