Fluid filled lumps

Definitely go and get them drained.  I had a seroma on my right breast drained four times after two lumpectomies in the same place, once by my breast care nurse, once by my plastic surgeon, and twice by my breast surgeon.  There was a slight 'pop' when the needle went in, and that was it.  A straw-coloured liquid is either drawn out or runs out, and the relief from pressure is enormous.  There is no need to fear it at all.  I asked for the last two to be done.  You don't need to brace yourself for pain at all.  Get it done and enjoy your holiday..