About one half of all mammary tumors are benign (not cancerous), which would fall into the category of mammary fibroadenoma, tumors that form out of the glandular portion of the mammary gland. (web-dvm.net)
A breast fibroadenoma will usually feel smooth, firm and rubbery. (verywell.com)
Despite that both sides of my breast ducts were messed up from fibroadenoma tumor removal surges (3 surges total). (skepticalob.com)