Spontaneous unilateral autoinflation of a saline-filled mammary implant.

We present the case of a woman with a massive volume increase in her right breast 12 years after breast augmentation with saline-filled silicone mammary implants (SMI). Tenderness of and pressure pain in the enlarged right breast were noted on physical examination. Intraoperatively, the right implant was seen to be markedly enlarged, altered in colour and filled with a brownish fluid as compared to the other side. No macroscopic damage, including to the valve of the enlarged SMI, was noticed. The liquid in the inflated SMI was subjected to biochemical analysis. Although neither cells nor nucleic acids were detected, 4mg/ml protein was found in the liquid of the autoinflated SMI. On SDS-PAGE separation, these proteins resolved in a pattern similar to that of serum proteins. This observation was corroborated by Western blots for several serum proteins. Surprisingly, proteins in the SMI liquid were significantly more glycosylated and oxidised than were serum proteins; this finding indicates a process of protein ageing. We hypothesise that the reason for this in vivo expansion was a defective valve and not colloid osmotic swelling, as previously suggested.