What are the symptoms of slow leakage in silicone/gummy bear breast implants (2012)?

You dont indicate if you are experiencing discomfort in the breasts, or if it involves swollen lymph nodes. Modern cohesive gel implants have very little gel " bleed "  from an intact implant. Typically , this usually causes hardening, or capsule contracture, which can be uncomfortable. A repeat MRI is reasonable at this point, and if you have lymph nodes that remain enlarged and tender, a biopsy may be indicated. Make an appointment with your surgeon for a thorough evaluation.

MRI is the most sensitive and specific test for detecting rupture. An in-office consultation with your PS would provide you with the most accurate advice in determining whether another MRI is warranted and perhaps lessen your anxiety.Kenneth Hughes, MD, Board Certified Plastic SurgeonLos Angeles, CA

Modern cohesive silicon gel breast implants a do not leak. However a rupture is possible as is capsular contracture., I would suggest that you see your plastic surgeon and have another MRI to see if there is any evidence of rupture.