I have one lump under my skin in left lower back hip area. It is hard and pain is reduced a lot, this one is there since two weeks. I don't know this is tumour or cancer I am scared. Tomorrow I am going to cancer care centre to test it. But main thing is I have tested 4 months hiv 4th generation test came nonreactive. Now am feeling this lump. If it is tumour or cancer my hiv 4th generation test is conclusive. I am I free from hiv else can because of tumour or cancer my hiv result shows false negative. I have swollen tongue as well.