DH had had a loss of vision to his left, it goes after a few hours, and he has been fine for the last 6 months. But due to this he has been going to the eye clinic at the hospital who diagnosed occular migraines. Today he had a follow up appointment and they showed him the MRI image of his brain, he has a thing there (circled in photo) he has had cancer before but they said it's nothing to worry about, surely he should see a specialist in that field to reassure us.
Did they say what it was/might be, when they told you not to worry about it? IMO with things like this, they should tell you what it is, and why its not a worry, not simply say, "this is nothing to worry about", particularly with your DH's history, where it would be totally natural for you to worry.
In that case no, I wouldn't be happy with them just saying "we don't know what this is, but its nothing to worry about." I mean, maybe they had it checked by someone, who told them what it was and that it was nothing to worry about, and by the time it got back to you, they only relayed the important bit that its nothing to worry about? If they're doing MRIs, they surely must have them checked by a specialist if they aren't actually trained to be able to fully read them properly themselves, otherwise there's no point doing the MRI.
The MRI would have been reported by a radiologist, hopefully a neuroradiologist as it is a brain scan. If they said it was nothing to worry about, one assumes that is what the report said. It probably also suggested your husband see a neurologist for clarification/explanation. I had a CT scan of my chest that unexpectedly showed up a nodule in my lung - thought to be of no importance and possibly present since birth, but the reporting radiologist advised I should see a chest physician for follow up. The "rules" lay down that people in this situation should have follow up scans for a couple of years to make sure there is no change in the lesion, so maybe this is a similar situation. It does seem unlikely they'd say it was nothing to worry about unless that is what the report said, so hopefully that's right. There are things that people have in their brains from birth, such as arachnoid cysts, about which nothing needs to be done and they never get any symptoms.