My ultrasound says i have unusual 12mm axiliary lymph node , it lacks hilum fatty.im doing a biopsy. is this something i should be concerned ? thanks

Yes: I am assuming you are feeling well. This is most likely due to a minor skin problem on your arm or hand, past or present. At your age, it is very likely that this will simply be a big lymph node. The chance of Hodgkin's / malignant lymphoma is quite small, and of some other illness even less. The decision to biopsy reflects only the reasonable concern that treatable disease might be found early.