10/15/2026
Your breast has made a cyst. Congratulations on your new roommate!
Breast cysts are fluid-filled sacs, and they're one of the things that can show up with fibrocystic breast changes.
You may have heard the older term fibrocystic breast disease, but we've mostly stopped calling it that because—rather dramatically—it isn't actually a disease. It's a common, benign way breast tissue can behave.
Cysts can appear, disappear, change size, get tender, and occasionally return after being drained.
But here's the important bit: New lump ≠ “eh, it's probably another cyst.”
You cannot reliably diagnose a new lump with your fingers. New or persistent breast changes still deserve evaluation.