During growth, due to an alteration in development, it may happen that the lining of the mammary gland present excessive rigidity and not properly expand along with the progressive growth of the mammary gland. This situation can cause the gland as it grows and dam sits on the skin that does not expand, have the tendency to herniate and out the place of least resistance, which is the thin skin of the nipple.

Treatment of a tuberous breasts or tubular (Tube-shaped) or goat or constrained, may include surgical release of the inside of the skin over the breast and placement of a breast implant, all through small incisions in the areola.
If the areola is too large, it can be corrected with the same incision.