I think that I know what you are talking about. occasionally I wil l get one or two lumps on the roof of my mouth, small, but larger than pimples. more like smooth pebbles. and they can be sore. they come for a couple of days and then disappear just before I get ill. this has been for the past few years so I have learned to use them as immune indicators and I do all that I can to boost my immune system and rest when I get them so that now I can usually fend off illnesses before the symptoms hit too hard. I have no idea what they are but nobody that I know has ever experienced them.