What is it and how do you get rid of it?

Today I was dismayed to find a light brownish looking haze beginning to cover the lens element cloud-like when viewed with a flashlight. There was a more ominous-looking broken ring at the very edge if the element where it meets the barrel but I couldn't determine if it was fungus or lens cleaner residue that had settled there from a previous cleaning. I separated the front and rear elements from the shutter and using Promaster Optic Clean, Olympic lens tissues, a microfiber lens cloth and condensation from my breath was able to clean the haze and residue from the elements. When not in use I store this lens in a Pelican waterproof case. No other lens stored in the same case exhibited a haze.

Was the haze the beginning of a fungal infection on the lens or something else?

Thomas