Detection of Pathologically Proven Silicone Lymphadenopathy: Ultrasonography Versus Magnetic Resonance Imaging

Objectives To compare the abilities of ultrasonography (US) and magnetic resonance imaging (MRI) in diagnosing silicone lymphadenopathy. Methods Consecutive patients with silicone breast implants who underwent axillary and intramammary lymph node core needle biopsies were retrospectively collected (December 2011–May 2017). Ultrasonographic examinations were analyzed for the presence of the US snowstorm sign, and MRI examinations were evaluated for the presence of the silicone signal. A pathologist reviewed all biopsied specimens. Ultrasonographic and MRI evaluations were compared to pathologic results. The sensitivity and specificity in diagnosing silicone lymphadenopathy were calculated for the snowstorm sign on US and the MRI silicone signal. Results Forty-one lymph node biopsies were included: 8 (19.5%) silicone-containing lymph nodes, 29 (70.7%) reactive nodes, and 4 (9.8%) malignant nodes. All nodes were evaluated by US, and 18 of 41 (43.9%) were evaluated by MRI. Seven of 8 (87.5%) silicone-containing nodes showed the snowstorm sign compared to none (0.0%) of the reactive or malignant nodes (P = .0001). One of 5 (20.0%) silicone-containing nodes evaluated by MRI showed the silicone signal compared to none (0.0%) of the reactive or malignant nodes (P = .278). The sensitivity and specificity of the snowstorm sign for diagnosing silicone lymphadenopathy were 87.5% and 100%, respectively, whereas those of the MRI silicone signal were 20.0% and 100%, respectively. Conclusions The US snowstorm sign is much more sensitive for silicone lymphadenopathy than the MRI silicone signal. In cases of suspected silicone lymphadenopathy, the use of US in addition to MRI should be contemplated.