I had a mastectomy (left breast and all nodes removed) in 2016. Within last few months noted that my collar bone on left side (from v) is twice as thick as right side. I initially thought this to be a side effect of the chemo. No pain per se in that area. Have a sore throat on left only plus banger of a headache above left eye in last week. This got me going and called oncologist for visit. Have appointment in few days and will repost once I get feedback. Seeing other posts made me realize this could potentially be a problem.