Reccuring raised colourless lumps on stomach

I have been getting horizontal, irregular shaped lumps on my stomach for some time now. They come and then go. They can vary in size from the size of a pea to the size of golf ball. Often when the lumps are first raised, it becomes quite itchy, though not uncomfortably so. The area around the raised lump is quite red, although the lump itself seems to be clear. The lump is very hard and solid.
Does anyone know what this might be?