Understanding Intracapsular Breast Implant Rupture on Ultrasound
What You're Seeing: The Anatomy of Intracapsular Rupture
When a breast implant ruptures intracapsularly, the elastomer shell of the implant fails but the fibrous capsule formed by the body around the implant remains intact, containing the silicone within this outer layer. 1
The ultrasound findings you're describing—material "inside and between the outer layer in the fibrous capsule"—represent the collapsed implant shell floating within silicone gel that remains contained by the fibrous capsule. This is the hallmark of intracapsular rupture. 1
Key Ultrasound Findings to Recognize
Specific signs of intracapsular rupture on ultrasound include: 1
- Stepladder sign: The collapsed implant shell appears as multiple parallel echogenic lines within the anechoic silicone gel
- Keyhole, noose, or subcapsular signs: Various configurations of the collapsed shell
- Loss of the normal featureless, anechoic appearance: An intact implant should be completely anechoic and smooth
Important caveat: A normal intact implant shows a smooth trilaminar margin (the capsule-shell complex) and is completely anechoic internally. Radial folds are normal infoldings of the shell and should not be mistaken for rupture. 1
Diagnostic Accuracy and Limitations
Ultrasound has variable accuracy for detecting intracapsular rupture, with reported sensitivities ranging from 30% to 98.3% depending on operator expertise. 1, 2
The ACR guidelines emphasize that if more than 2 signs of rupture are present on ultrasound, you can act on these findings; if only 1 sign is present, MRI confirmation is recommended. 1, 2 This is critical because several mimics exist including reverberation artifacts, radial folds, and silicone impurities that can falsely suggest rupture. 1
Clinical Implications and Management
Intracapsular rupture is typically asymptomatic and poses minimal immediate health risk, with no consensus requiring surgery in asymptomatic patients. 3
However, the ACR recommends referral to plastic surgery for evaluation and surgical planning, particularly because: 3
- The rupture may progress from intracapsular to extracapsular over time (observed in 11% of cases in one study) 4
- Leaving ruptured implants in place complicates future breast imaging and cancer detection 3
- Patients may develop nonspecific breast symptoms (2.1-fold increased odds) 4
When to Escalate to MRI
MRI without contrast is the gold standard for confirming intracapsular rupture, with 87% sensitivity and 89.9% specificity. 2, 3
- Only 1 ultrasound sign of rupture is present
- Ultrasound findings are equivocal
- You need definitive confirmation before surgical planning
On MRI, complete intracapsular rupture shows the pathognomonic "linguini" or "wavy-line" sign (the collapsed shell floating within silicone), while incomplete rupture shows "keyhole," "teardrop," or "hang noose" signs. 1, 2
Critical Distinction: Intracapsular vs. Extracapsular
You must differentiate intracapsular from extracapsular rupture, as the latter requires more urgent surgical intervention. 3
Extracapsular rupture appears on ultrasound as the classic "snowstorm" pattern—highly echogenic scattered and reverberating echoes with well-defined anterior margin and posterior shadowing—representing free silicone in breast parenchyma outside the fibrous capsule. 1 This finding is diagnostic of extracapsular rupture and mandates plastic surgery referral within 2-4 weeks. 3
Practical Management Algorithm
If ultrasound shows ≥2 signs of intracapsular rupture: Refer to plastic surgery for evaluation; shared decision-making regarding explantation vs. observation 1, 2
If ultrasound shows only 1 sign or equivocal findings: Order MRI without contrast for definitive diagnosis 1, 2
If extracapsular rupture (snowstorm pattern): Urgent plastic surgery referral within 2-4 weeks 3
If patient opts for observation: Clinical follow-up with imaging every 2-3 years per FDA recommendations, as progression to extracapsular rupture can occur 3, 4