I've had a swollen lymphnode in my neck for about a month that I know of now. I have a sebaceous cyst right next to it as well. I had annual blood labs done about 3 weeks ago. Doctor said my CBC was normal. So my question is 1) Can a srbaceous cyst cause a swollen lymph node? 2). Would my CBC be off if I had lymphoma? 23 yr old white male. I'm worried about cancers because i spent 15 months in Iraq where we had open air burn pits 24/7 and the only water available was sitting outside in direct sunlight in plastic bottles for god knows how long.