What Does Prominence Of Cerebella Pontine Angle On CT Head Suggest?

On a recent head CT, I was found to have a "focal prominence of the right cerebella pontine angle, consistent with incidental arachnoid cyst or epidermoid (much less likely per radiology report). My internist has siad that no follow up is necessary. I need to know what is the likely progression and whether ornot I should get a second opinion.