Key Points Question Are cohesive gel breast implants associated with silicone bleed? Findings In this case series including 389 women with silicone gel breast implants, 384 women (98.8%) showed silicones in the tissues. There was no statistically significant difference between women with cohesive gel implants and those with noncohesive gel implants. Meaning These findings suggest that cohesive silicone gel breast implants leak silicones and may potentially harm patients, as noncohesive gel implants do.