I have three nepenthes in which some of the leaves have 1/16 of an inch lumps in it. 5-10 per leaf. they are not stuck to the leave, they come out of the leaf from the inside. They of the same colour of the leaf and round. The plants don't look sick at all, and the leaves looks healthy except for the presence of those tiny lumps on the upper surface.
I look forward to anybody's input. Thanks