About a year ago my neurologist ran an MRI, trying to figure out what was going on. The only abnormality they found was a large growth in my left maxillary sinus. Referred to an ear/nose/throat specialist, who dx'd it as a cyst. Said we could remove it, but it wasn't strictly necessary. I'm also prone to getting dime sized cysts just below the skin, usually on my hips.

My question is, how big of a cyst can lyme form? I understand the cystic form is generally microscopic, but could it, I don't know, trigger the growth of larger, fluid filled cysts?

Sinusitis is common with Lyme. My sinusitis and the post nasal drip I had had for years went away after treatment with a combo of flagyl & zithromax. But at the beginning of that treatment I thought my nasal sinuses were blowing up and I had a terrible smell of something like burnt plastic. My tongue also got very fuzzy and I thought it was a fungal attack. It wasn't. But it was scary for a while.

CA Quest

I have the same type of cyst just below my right eyball. It is harmless, except that I do have sinus trouble on that side of my head. My ENT said he could remove it, if I wanted. But, when he explained the procedure I felt ill so I said no thanks.