On a mammogram what does stable right breast nodule consistent with benign etiology (br-rads 2 benign) mean? what's does the meaning of etiology?

Benign: Bi-RADS is a system used by radiologist to categorize the level of suspicion of breast lesion for cancer. It includes 0-6. BiRADS 2 is benign, meaning NOT a cancer. Bi-RADS 4 or above is more suspicious for cancer. Thus, biopsy should be done. But, the system does not incorporate clinical suspicion. So, biopsy may still be indicated for low Bi-RADS lesion if clinical suspicion is high.

Non cancerous: It means that a nodule that is in the right breast has remained unchanged and it is from a non cancerous process.