Breast siliconoma diagnostic imaging challenges and recommendations: a case series

Free liquid silicone injection (FLSI) cases are still sporadically encountered despite advances in breast augmentation techniques. The American College of Radiology (ACR) guidelines support the use of breast magnetic resonance imaging (MRI) for silicone complication mapping in conventional medical-grade implant cases. However, FLSI-related complications remain lesser-known in clinical practice. A limited familiarity with their imaging appearances hinders accurate image interpretation and timely clinical management. This case series illustrates uncommonly reported multimodal imaging variations of siliconomas with histopathologic correlation. Two 56-year-old women (one Malay and one Chinese) with histories of FLSI presented with a unilateral breast lump and nipple discharge, respectively. Both patients underwent mammography, ultrasonography and MRI. Mammography showed innumerable siliconomas, potentially obscuring malignant lesions. In both cases, ultrasonography had limited diagnostic value. Dynamic contrast-enhanced MRI provided superior visualization but remained challenging to interpret due to the multiplicity of lesions and overlapping imaging features between benign silicone-related complications and malignancy. Both patients had uneventful surgeries, and histopathology confirmed the final diagnoses. This case series is a preliminary step toward larger longitudinal cohort studies, aimed at characterizing the full spectrum of FLSI imaging appearances. Improved understanding can reduce diagnostic uncertainty where silicone-related changes obscure or mimic malignancy. These case findings also highlight the need for standardized, evidence-based, FLSI-specific imaging protocols and clinical guidelines to support informed decision-making and optimize patient care.