E1496. Silicone Imaging in Breast Radiology: An Educational Review
  1. Katherine Smith; Mayo Clinic
  2. Lyndsay Viers; Mayo Clinic
  3. Tara Anderson; Mayo Clinic
  4. Katrina Glazebrook; Mayo Clinic
Breast reconstruction with silicone implants is commonly performed following breast cancer surgery and for breast augmentation. Because of this procedure’s ubiquity, general radiologists, and especially breast radiologists, should be proficient in the evaluation of silicone breast implants and their complications.

Educational Goals / Teaching Points
In this educational review, we will present multiple cases to review imaging findings of silicone breast implants and their complications, both common and uncommon. Specialized imaging techniques for implant evaluation will be discussed, including silicone-sensitive MRI sequences, dual energy CT, and MR elastography. The implications of imaging findings and the role of imaging in directing treatment will be discussed. This educational review is targeted to general radiologists, breast radiologists, and radiologists-in-training.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Common complications of silicone breast implants include intracapsular rupture, extracapsular rupture, and gel bleed, in which unpolymerized silicone molecules permeate through the intact elastomer shell of the implant. Silicone from gel bleed and envelope rupture may be taken up into the lymphatic system and spread to distant sites. The prevalence of silicone breast implant rupture in a population-based study has been reported to be as high as 55%, with 22% of ruptured implants showing extracapsular spread of silicone. Rare sites of silicone spread can include the liver, spleen, and lungs. Evaluation for implant integrity and lymphatic spread of silicone can be accomplished with multiple imaging modalities, in a tailored and patient-based approach. A notable complication of silicone breast implants is breast implant associated anaplastic large cell lymphoma (BIA-ALCL). With 467 cases reported worldwide, this is an extremely rare complication of silicone implants. BIA-ALCL is a clinically significant breast implant complication with significant management considerations, therefore breast and general radiologists should have an understanding of the appearance of this entity on multiple modalities. An additional very rare complication is squamous cell carcinoma related to implants with 5 cases noted in the literature.

It is important to recognize imaging correlation of intracapsular and extracapsular silicone from implant rupture within the breast. Correlation of imaging findings with mammograms, ultrasound, dual energy CT, PET/CT, and silicone sensitive MRI sequences can be helpful in evaluating complications of breast implant rupture and breast implant-associated cancers.