Sore, swollen lymph nodes under my right arm for 8 months. spread to groin, & behind both knees. ct scan neg. had two sonograms under right arm, but surgeons say nodes not big enough to biopsy?

May need 2nd opinion: Sore lymph nodes are usually inflammatory and not malignant. I'm assuming that your nodes are less than 1 cm in size if your surgeon says they are too small to biopsy. Malignant nodes usually grow slowly to greater than 1cm. That is not an absolute rule and biopsy can be considered if nodes are persistent and are otherwise unexplained. If they persist and are concerning, get another opinion.