In some patients, the filler material in the implant can leak through an intact implant shell. This happens when the filler material is small enough to fit through the tiny gaps in the shell, similar to car tyres that become flat even though there is no obvious puncture.
Breast implants, because they are foreign material, are walled off by the body in scar tissue. This is known as a capsule. Intracapsular rupture means that the implant shell is damaged, but the filler material is contained within the capsule. Most women with intracapsular rupture are completely unaware of this. Some may notice a slight change in shape of the breast or how the breast feels.
When silicone from ruptured implants spreads beyond the capsule, patients are usually symptomatic. There may be a change in breast shape, lumps you can feel, or redness of the overlying skin (inflammatory changes).