They've confirmed that the enlarged (and removed) parathyroid was indeed an adenoma: a benign tumour. Also taken a blood sample to check calcium and parathyroid hormone levels are back to normal. They'll write to me and my GP and let me know the results, if so we're all done and dusted. He didn't say what happens if they're still elevated! Also apparently my scar should be all but invisible within 12 months, which is excellent news. It's fairly unobtrusive anyway, all things considered. All good.
In other news I'm actively looking at wedding venues now: have three visits to colleges lined up, all inconveniently on different weekends, but Mum and Dad will be able to come along for one of them. V exciting, and scarily expensive looking!