Hi Georgie, the stringy thing you described might well be cording. This can occur after removal of some lymph nodes, and is a tightness that happens along the empty lymph channels. I haven't experienced this, but from what I have read, I don't think it is serious. Sometimes you might need a physio to massage and stretch these for relief. If you put cording into the search engine on this site you should pick up some advice. You could also google cording and see what comes up. All the best. Love Chris xx