Hidden breast cancer after breast augmentation, not presenting as a hypoechoic mass lesion, diagnosed using colour Doppler ultrasound.

The main concern after breast augmentation with silicone injection is that silicone granulomas make it difficult to detect breast cancer. A case of breast cancer was diagnosed using colour Doppler ultrasound (CD) to detect an non-palpable mass not presenting as a hypoechoic mass lesion. An 83-year-old woman was incidentally found to have a lesion in her right breast, which was injected with silicone, showing 18F-fluorodeoxyglucose (FDG) uptake; the lesion was suspected to be breast cancer or silicone granuloma. A mass at the FDG uptake site was not detected on ultrasonography (US); however, observation using CD revealed a slightly hypoechoic area with hypervascularity. Core needle biopsy showed invasive ductal carcinoma. Patients in whom US does not reveal lesions after breast augmentation with silicone injection should undergo CD to detect hypervascularised tissue. To prevent false-negative biopsy results, CD is essential to detect cancer at suspected sites.